diff --git a/CHANGELOG.md b/CHANGELOG.md
index 39a81d269..96a149c5c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -176,12 +176,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - `/api/v1/pleroma/scrobble`
   - `/api/v1/pleroma/accounts/{id}/scrobbles`
 - Deprecated endpoints
-  - `/api/v1/pleroma/chats`
   - `/api/v1/notifications/dismiss`
   - `/api/v1/search`
   - `/api/v1/statuses/{id}/card` 
-- Chats, they were half-baked. Just use PMs.
 - Prometheus, it causes massive slowdown
+- LDAP authenticator
 
 ## 2022.07
 
diff --git a/config/config.exs b/config/config.exs
index 5eaa8ce76..e11c774e5 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -269,6 +269,11 @@ config :pleroma, :welcome,
     sender_nickname: nil,
     message: nil
   ],
+  chat_message: [
+    enabled: false,
+    sender_nickname: nil,
+    message: nil
+  ],
   email: [
     enabled: false,
     sender: nil,
@@ -763,8 +768,7 @@ config :pleroma, :frontends,
     "mastodon-fe" => %{
       "name" => "mastodon-fe",
       "git" => "https://akkoma.dev/AkkomaGang/masto-fe",
-      "build_url" =>
-        "https://akkoma-updates.s3-website.fr-par.scw.cloud/frontend/${ref}/masto-fe.zip",
+      "build_url" => "https://akkoma-updates.s3-website.fr-par.scw.cloud/frontend/${ref}/masto-fe.zip",
       "build_dir" => "distribution",
       "ref" => "akkoma"
     },
diff --git a/config/description.exs b/config/description.exs
index 2a2d70a7b..6cceaeb51 100644
--- a/config/description.exs
+++ b/config/description.exs
@@ -957,7 +957,7 @@ config :pleroma, :config_description, [
         key: :privileged_staff,
         type: :boolean,
         description:
-          "Let moderators access sensitive data (e.g. updating user credentials, get password reset token, delete users, index and read private statuses)"
+          "Let moderators access sensitive data (e.g. updating user credentials, get password reset token, delete users, index and read private statuses and chats)"
       },
       %{
         key: :local_bubble,
@@ -1006,6 +1006,35 @@ config :pleroma, :config_description, [
           }
         ]
       },
+      %{
+        key: :chat_message,
+        type: :keyword,
+        descpiption: "Chat message settings",
+        children: [
+          %{
+            key: :enabled,
+            type: :boolean,
+            description: "Enables sending a chat message to newly registered users"
+          },
+          %{
+            key: :message,
+            type: :string,
+            description:
+              "A message that will be sent to newly registered users as a chat message",
+            suggestions: [
+              "Hello, welcome on board!"
+            ]
+          },
+          %{
+            key: :sender_nickname,
+            type: :string,
+            description: "The nickname of the local user that sends a welcome chat message",
+            suggestions: [
+              "lain"
+            ]
+          }
+        ]
+      },
       %{
         key: :email,
         type: :keyword,
@@ -2624,6 +2653,27 @@ config :pleroma, :config_description, [
       }
     ]
   },
+  %{
+    group: :pleroma,
+    key: :shout,
+    type: :group,
+    description: "Pleroma shout settings",
+    children: [
+      %{
+        key: :enabled,
+        type: :boolean,
+        description: "Enables the backend Shoutbox chat feature."
+      },
+      %{
+        key: :limit,
+        type: :integer,
+        description: "Shout message character limit.",
+        suggestions: [
+          5_000
+        ]
+      }
+    ]
+  },
   %{
     group: :pleroma,
     key: :http,
diff --git a/docs/docs/configuration/cheatsheet.md b/docs/docs/configuration/cheatsheet.md
index 4e84b9a44..f2adc1a45 100644
--- a/docs/docs/configuration/cheatsheet.md
+++ b/docs/docs/configuration/cheatsheet.md
@@ -8,6 +8,11 @@ For from source installations Akkoma configuration works by first importing the
 
 To add configuration to your config file, you can copy it from the base config. The latest version of it can be viewed [here](https://akkoma.dev/AkkomaGang/akkoma/src/branch/develop/config/config.exs). You can also use this file if you don't know how an option is supposed to be formatted.
 
+## :shout
+
+* `enabled` - Enables the backend Shoutbox chat feature. Defaults to `true`.
+* `limit` - Shout character limit. Defaults to `5_000`
+
 ## :instance
 * `name`: The instance’s name.
 * `email`: Email used to reach an Administrator/Moderator of the instance.
@@ -76,6 +81,10 @@ To add configuration to your config file, you can copy it from the base config.
   * `enabled`: Enables the send a direct message to a newly registered user. Defaults to `false`.
   * `sender_nickname`: The nickname of the local user that sends the welcome message.
   * `message`: A message that will be send to a newly registered users as a direct message.
+* `chat_message`: - welcome message sent as a chat message.
+  * `enabled`: Enables the send a chat message to a newly registered user. Defaults to `false`.
+  * `sender_nickname`: The nickname of the local user that sends the welcome message.
+  * `message`: A message that will be send to a newly registered users as a chat message.
 * `email`: - welcome message sent as a email.
   * `enabled`: Enables the send a welcome email to a newly registered user. Defaults to `false`.
   * `sender`: The email address or tuple with `{nickname, email}` that will use as sender to the welcome email.
diff --git a/docs/docs/development/API/admin_api.md b/docs/docs/development/API/admin_api.md
index 958388879..23998cb49 100644
--- a/docs/docs/development/API/admin_api.md
+++ b/docs/docs/development/API/admin_api.md
@@ -1031,6 +1031,7 @@ Most of the settings will be applied in `runtime`, this means that you don't nee
   - `:hackney_pools`
   - `:connections_pool`
   - `:pools`
+  - `:chat`
 - partially settings inside these keys:
   - `:seconds_valid` in `Pleroma.Captcha`
   - `:proxy_remote` in `Pleroma.Upload`
@@ -1393,6 +1394,127 @@ Loads json generated from `config/descriptions.exs`.
 
 ```
 
+## GET /api/v1/pleroma/admin/users/:nickname/chats
+
+### List a user's chats
+
+- Params: None
+
+- Response:
+
+```json
+[
+   {
+      "sender": {
+        "id": "someflakeid",
+        "username": "somenick",
+        ...
+      },
+      "receiver": {
+        "id": "someflakeid",
+        "username": "somenick",
+        ...
+      },
+      "id" : "1",
+      "unread" : 2,
+      "last_message" : {...}, // The last message in that chat
+      "updated_at": "2020-04-21T15:11:46.000Z"
+   }
+]
+```
+
+## GET /api/v1/pleroma/admin/chats/:chat_id
+
+### View a single chat
+
+- Params: None
+
+- Response:
+
+```json
+{
+  "sender": {
+    "id": "someflakeid",
+    "username": "somenick",
+    ...
+  },
+  "receiver": {
+    "id": "someflakeid",
+    "username": "somenick",
+    ...
+  },
+  "id" : "1",
+  "unread" : 2,
+  "last_message" : {...}, // The last message in that chat
+  "updated_at": "2020-04-21T15:11:46.000Z"
+}
+```
+
+## GET /api/v1/pleroma/admin/chats/:chat_id/messages
+
+### List the messages in a chat
+
+- Params: `max_id`, `min_id`
+
+- Response:
+
+```json
+[
+  {
+    "account_id": "someflakeid",
+    "chat_id": "1",
+    "content": "Check this out :firefox:",
+    "created_at": "2020-04-21T15:11:46.000Z",
+    "emojis": [
+      {
+        "shortcode": "firefox",
+        "static_url": "https://dontbulling.me/emoji/Firefox.gif",
+        "url": "https://dontbulling.me/emoji/Firefox.gif",
+        "visible_in_picker": false
+      }
+    ],
+    "id": "13",
+    "unread": true
+  },
+  {
+    "account_id": "someflakeid",
+    "chat_id": "1",
+    "content": "Whats' up?",
+    "created_at": "2020-04-21T15:06:45.000Z",
+    "emojis": [],
+    "id": "12",
+    "unread": false
+  }
+]
+```
+
+## DELETE /api/v1/pleroma/admin/chats/:chat_id/messages/:message_id
+
+### Delete a single message
+
+- Params: None
+
+- Response:
+
+```json
+{
+  "account_id": "someflakeid",
+  "chat_id": "1",
+  "content": "Check this out :firefox:",
+  "created_at": "2020-04-21T15:11:46.000Z",
+  "emojis": [
+    {
+      "shortcode": "firefox",
+      "static_url": "https://dontbulling.me/emoji/Firefox.gif",
+      "url": "https://dontbulling.me/emoji/Firefox.gif",
+      "visible_in_picker": false
+    }
+  ],
+  "id": "13",
+  "unread": false
+}
+```
+
 ## `GET /api/v1/pleroma/admin/instance_document/:document_name`
 
 ### Get an instance document
diff --git a/docs/docs/development/API/chats.md b/docs/docs/development/API/chats.md
new file mode 100644
index 000000000..69b214ab1
--- /dev/null
+++ b/docs/docs/development/API/chats.md
@@ -0,0 +1,255 @@
+# Chats
+
+Chats are a way to represent an IM-style conversation between two actors. They are not the same as direct messages and they are not `Status`es, even though they have a lot in common.
+
+## Why Chats?
+
+There are no 'visibility levels' in ActivityPub, their definition is purely a Mastodon convention. Direct Messaging between users on the fediverse has mostly been modeled by using ActivityPub addressing following Mastodon conventions on normal `Note` objects. In this case, a 'direct message' would be a message that has no followers addressed and also does not address the special public actor, but just the recipients in the `to` field. It would still be a `Note` and is presented with other `Note`s as a `Status` in the API.
+
+This is an awkward setup for a few reasons:
+
+- As DMs generally still follow the usual `Status` conventions, it is easy to accidentally pull somebody into a DM thread by mentioning them. (e.g. "I hate @badguy so much")
+- It is possible to go from a publicly addressed `Status` to a DM reply, back to public, then to a 'followers only' reply, and so on. This can be become very confusing, as it is unclear which user can see which part of the conversation.
+- The standard `Status` format of implicit addressing also leads to rather ugly results if you try to display the messages as a chat, because all the recipients are always mentioned by name in the message.
+- As direct messages are posted with the same api call (and usually same frontend component) as public messages, accidentally making a public message private or vice versa can happen easily. Client bugs can also lead to this, accidentally making private messages public.
+
+As a measure to improve this situation, the `Conversation` concept and related Akkoma extensions were introduced. While it made it possible to work around a few of the issues, many of the problems remained and it didn't see much adoption because it was too complicated to use correctly.
+
+## Chats explained
+For this reasons, Chats are a new and different entity, both in the API as well as in ActivityPub. A quick overview:
+
+- Chats are meant to represent an instant message conversation between two actors. For now these are only 1-on-1 conversations, but the other actor can be a group in the future.
+- Chat messages have the ActivityPub type `ChatMessage`. They are not `Note`s. Servers that don't understand them will just drop them.
+- The only addressing allowed in `ChatMessage`s is one single ActivityPub actor in the `to` field.
+- There's always only one Chat between two actors. If you start chatting with someone and later start a 'new' Chat, the old Chat will be continued.
+- `ChatMessage`s are posted with a different api, making it very hard to accidentally send a message to the wrong person.
+- `ChatMessage`s don't show up in the existing timelines.
+- Chats can never go from private to public. They are always private between the two actors.
+
+## Caveats
+
+- Chats are NOT E2E encrypted (yet). Security is still the same as email.
+
+## API
+
+In general, the way to send a `ChatMessage` is to first create a `Chat`, then post a message to that `Chat`. `Group`s will later be supported by making them a sub-type of `Account`.
+
+This is the overview of using the API. The API is also documented via OpenAPI, so you can view it and play with it by pointing SwaggerUI or a similar OpenAPI tool to `https://yourinstance.tld/api/openapi`.
+
+### Creating or getting a chat.
+
+To create or get an existing Chat for a certain recipient (identified by Account ID)
+you can call:
+
+`POST /api/v1/pleroma/chats/by-account-id/:account_id`
+
+The account id is the normal FlakeId of the user
+```
+POST /api/v1/pleroma/chats/by-account-id/someflakeid
+```
+
+If you already have the id of a chat, you can also use
+
+```
+GET /api/v1/pleroma/chats/:id
+```
+
+There will only ever be ONE Chat for you and a given recipient, so this call
+will return the same Chat if you already have one with that user.
+
+Returned data:
+
+```json
+{
+  "account": {
+    "id": "someflakeid",
+    "username": "somenick",
+    ...
+  },
+  "id" : "1",
+  "unread" : 2,
+  "last_message" : {...}, // The last message in that chat
+  "updated_at": "2020-04-21T15:11:46.000Z"
+}
+```
+
+### Marking a chat as read
+
+To mark a number of messages in a chat up to a certain message as read, you can use
+
+`POST /api/v1/pleroma/chats/:id/read`
+
+
+Parameters:
+- last_read_id: Given this id, all chat messages until this one will be marked as read. Required.
+
+
+Returned data:
+
+```json
+{
+  "account": {
+    "id": "someflakeid",
+    "username": "somenick",
+    ...
+  },
+  "id" : "1",
+  "unread" : 0,
+  "updated_at": "2020-04-21T15:11:46.000Z"
+}
+```
+
+### Marking a single chat message as read
+
+To set the `unread` property of a message to `false`
+
+`POST /api/v1/pleroma/chats/:id/messages/:message_id/read`
+
+Returned data:
+
+The modified chat message
+
+### Getting a list of Chats
+
+`GET /api/v1/pleroma/chats`
+
+This will return a list of chats that you have been involved in, sorted by their
+last update (so new chats will be at the top).
+
+Parameters:
+
+- with_muted: Include chats from muted users (boolean).
+
+Returned data:
+
+```json
+[
+   {
+      "account": {
+        "id": "someflakeid",
+        "username": "somenick",
+        ...
+      },
+      "id" : "1",
+      "unread" : 2,
+      "last_message" : {...}, // The last message in that chat
+      "updated_at": "2020-04-21T15:11:46.000Z"
+   }
+]
+```
+
+The recipient of messages that are sent to this chat is given by their AP ID.
+No pagination is implemented for now.
+
+### Getting the messages for a Chat
+
+For a given Chat id, you can get the associated messages with
+
+`GET /api/v1/pleroma/chats/:id/messages`
+
+This will return all messages, sorted by most recent to least recent. The usual
+pagination options are implemented.
+
+Returned data:
+
+```json
+[
+  {
+    "account_id": "someflakeid",
+    "chat_id": "1",
+    "content": "Check this out :firefox:",
+    "created_at": "2020-04-21T15:11:46.000Z",
+    "emojis": [
+      {
+        "shortcode": "firefox",
+        "static_url": "https://dontbulling.me/emoji/Firefox.gif",
+        "url": "https://dontbulling.me/emoji/Firefox.gif",
+        "visible_in_picker": false
+      }
+    ],
+    "id": "13",
+    "unread": true
+  },
+  {
+    "account_id": "someflakeid",
+    "chat_id": "1",
+    "content": "Whats' up?",
+    "created_at": "2020-04-21T15:06:45.000Z",
+    "emojis": [],
+    "id": "12",
+    "unread": false,
+    "idempotency_key": "75442486-0874-440c-9db1-a7006c25a31f"
+  }
+]
+```
+
+- idempotency_key: The copy of the `idempotency-key` HTTP request header that can be used for optimistic message sending. Included only during the first few minutes after the message creation.
+
+### Posting a chat message
+
+Posting a chat message for given Chat id works like this:
+
+`POST /api/v1/pleroma/chats/:id/messages`
+
+Parameters:
+- content: The text content of the message. Optional if media is attached.
+- media_id: The id of an upload that will be attached to the message.
+
+Currently, no formatting beyond basic escaping and emoji is implemented.
+
+Returned data:
+
+```json
+{
+  "account_id": "someflakeid",
+  "chat_id": "1",
+  "content": "Check this out :firefox:",
+  "created_at": "2020-04-21T15:11:46.000Z",
+  "emojis": [
+    {
+      "shortcode": "firefox",
+      "static_url": "https://dontbulling.me/emoji/Firefox.gif",
+      "url": "https://dontbulling.me/emoji/Firefox.gif",
+      "visible_in_picker": false
+    }
+  ],
+  "id": "13",
+  "unread": false
+}
+```
+
+### Deleting a chat message
+
+Deleting a chat message for given Chat id works like this:
+
+`DELETE /api/v1/pleroma/chats/:chat_id/messages/:message_id`
+
+Returned data is the deleted message.
+
+### Notifications
+
+There's a new `pleroma:chat_mention` notification, which has this form. It is not given out in the notifications endpoint by default, you need to explicitly request it with `include_types[]=pleroma:chat_mention`:
+
+```json
+{
+  "id": "someid",
+  "type": "pleroma:chat_mention",
+  "account": { ... } // User account of the sender,
+  "chat_message": {
+    "chat_id": "1",
+    "id": "10",
+    "content": "Hello",
+    "account_id": "someflakeid",
+    "unread": false
+  },
+  "created_at": "somedate"
+}
+```
+
+### Streaming
+
+There is an additional `user:pleroma_chat` stream. Incoming chat messages will make the current chat be sent to this `user` stream. The `event` of an incoming chat message is `pleroma:chat_update`. The payload is the updated chat with the incoming chat message in the `last_message` field.
+
+### Web Push
+
+If you want to receive push messages for this type, you'll need to add the `pleroma:chat_mention` type to your alerts in the push subscription.
diff --git a/docs/docs/development/API/differences_in_mastoapi_responses.md b/docs/docs/development/API/differences_in_mastoapi_responses.md
index b41561c45..1a42dbb8e 100644
--- a/docs/docs/development/API/differences_in_mastoapi_responses.md
+++ b/docs/docs/development/API/differences_in_mastoapi_responses.md
@@ -103,11 +103,13 @@ Has these additional fields under the `pleroma` object:
 - `hide_followers_count`: boolean, true when the user has follower stat hiding enabled
 - `hide_follows_count`: boolean, true when the user has follow stat hiding enabled
 - `settings_store`: A generic map of settings for frontends. Opaque to the backend. Only returned in `/api/v1/accounts/verify_credentials` and `/api/v1/accounts/update_credentials`
+- `chat_token`: The token needed for Akkoma shoutbox. Only returned in `/api/v1/accounts/verify_credentials`
 - `deactivated`: boolean, true when the user is deactivated
 - `allow_following_move`: boolean, true when the user allows automatically follow moved following accounts
 - `unread_conversation_count`: The count of unread conversations. Only returned to the account owner.
 - `unread_notifications_count`: The count of unread notifications. Only returned to the account owner.
 - `notification_settings`: object, can be absent. See `/api/v1/pleroma/notification_settings` for the parameters/keys returned.
+- `accepts_chat_messages`: boolean, but can be null if we don't have that information about a user
 - `favicon`: nullable URL string, Favicon image of the user's instance
 
 ### Source
@@ -161,6 +163,15 @@ The `type` value is `pleroma:emoji_reaction`. Has these fields:
 - `account`: The account of the user who reacted
 - `status`: The status that was reacted on
 
+### ChatMention Notification (not default)
+
+This notification has to be requested explicitly.
+
+The `type` value is `pleroma:chat_mention`
+
+- `account`: The account who sent the message
+- `chat_message`: The chat message
+
 ### Report Notification (not default)
 
 This notification has to be requested explicitly.
@@ -175,7 +186,7 @@ The `type` value is `pleroma:report`
 Accepts additional parameters:
 
 - `exclude_visibilities`: will exclude the notifications for activities with the given visibilities. The parameter accepts an array of visibility types (`public`, `unlisted`, `private`, `direct`). Usage example: `GET /api/v1/notifications?exclude_visibilities[]=direct&exclude_visibilities[]=private`.
-- `include_types`: will include the notifications for activities with the given types. The parameter accepts an array of types (`mention`, `follow`, `reblog`, `favourite`, `move`, `pleroma:emoji_reaction`, `pleroma:report`). Usage example: `GET /api/v1/notifications?include_types[]=mention&include_types[]=reblog`.
+- `include_types`: will include the notifications for activities with the given types. The parameter accepts an array of types (`mention`, `follow`, `reblog`, `favourite`, `move`, `pleroma:emoji_reaction`, `pleroma:chat_mention`, `pleroma:report`). Usage example: `GET /api/v1/notifications?include_types[]=mention&include_types[]=reblog`.
 
 ## DELETE `/api/v1/notifications/destroy_multiple`
 
@@ -233,6 +244,7 @@ Additional parameters can be added to the JSON body/Form data:
 - `pleroma_background_image` - sets the background image of the user. Can be set to "" (an empty string) to reset.
 - `discoverable` - if true, external services (search bots) etc. are allowed to index / list the account (regardless of this setting, user will still appear in regular search results).
 - `actor_type` - the type of this account.
+- `accepts_chat_messages` - if false, this account will reject all chat messages.
 - `language` - user's preferred language for receiving emails (digest, confirmation, etc.)
 
 All images (avatar, banner and background) can be reset to the default by sending an empty string ("") instead of a file.
@@ -292,6 +304,7 @@ Has these additional parameters (which are the same as in Akkoma-API):
 `GET /api/v1/instance` has additional fields
 
 - `max_toot_chars`: The maximum characters per post
+- `chat_limit`: The maximum characters per chat message
 - `description_limit`: The maximum characters per image description
 - `poll_limits`: The limits of polls
 - `upload_limit`: The maximum upload file size
@@ -312,6 +325,7 @@ Has these additional parameters (which are the same as in Akkoma-API):
 
 Permits these additional alert types:
 
+- pleroma:chat_mention
 - pleroma:emoji_reaction
 
 ## Markers
@@ -322,6 +336,10 @@ Has these additional fields under the `pleroma` object:
 
 ## Streaming
 
+### Chats
+
+There is an additional `user:pleroma_chat` stream. Incoming chat messages will make the current chat be sent to this `user` stream. The `event` of an incoming chat message is `pleroma:chat_update`. The payload is the updated chat with the incoming chat message in the `last_message` field.
+
 ### Remote timelines
 
 For viewing remote server timelines, there are `public:remote` and `public:remote:media` streams. Each of these accept a parameter like `?instance=lain.com`.
diff --git a/docs/docs/development/API/nodeinfo.md b/docs/docs/development/API/nodeinfo.md
index 08453cdc8..30150ac47 100644
--- a/docs/docs/development/API/nodeinfo.md
+++ b/docs/docs/development/API/nodeinfo.md
@@ -44,8 +44,11 @@ See also [the Nodeinfo standard](https://nodeinfo.diaspora.software/).
          "shareable_emoji_packs",
          "multifetch",
          "pleroma:api/v1/notifications:include_types_filter",
+         "chat",
+         "shout",
          "relay",
-         "pleroma_emoji_reactions"
+         "pleroma_emoji_reactions",
+         "pleroma_chat_messages"
       ],
       "federation":{
          "enabled":true,
@@ -201,8 +204,11 @@ See also [the Nodeinfo standard](https://nodeinfo.diaspora.software/).
          "shareable_emoji_packs",
          "multifetch",
          "pleroma:api/v1/notifications:include_types_filter",
+         "chat",
+         "shout",
          "relay",
-         "pleroma_emoji_reactions"
+         "pleroma_emoji_reactions",
+         "pleroma_chat_messages"
       ],
       "federation":{
          "enabled":true,
diff --git a/docs/docs/development/ap_extensions.md b/docs/docs/development/ap_extensions.md
index bf9420272..3d1caeb3e 100644
--- a/docs/docs/development/ap_extensions.md
+++ b/docs/docs/development/ap_extensions.md
@@ -26,3 +26,40 @@ Response: HTTP 201 Created with the object into the body, no `Location` header p
 
 The object given in the reponse should then be inserted into an Object's `attachment` field.
 
+## ChatMessages
+
+`ChatMessage`s are the messages sent in 1-on-1 chats. They are similar to
+`Note`s, but the addresing is done by having a single AP actor in the `to`
+field. Addressing multiple actors is not allowed. These messages are always
+private, there is no public version of them. They are created with a `Create`
+activity.
+
+They are part of the `litepub` namespace as `http://litepub.social/ns#ChatMessage`.
+
+Example:
+
+```json
+{
+  "actor": "http://2hu.gensokyo/users/raymoo",
+  "id": "http://2hu.gensokyo/objects/1",
+  "object": {
+    "attributedTo": "http://2hu.gensokyo/users/raymoo",
+    "content": "You expected a cute girl? Too bad.",
+    "id": "http://2hu.gensokyo/objects/2",
+    "published": "2020-02-12T14:08:20Z",
+    "to": [
+      "http://2hu.gensokyo/users/marisa"
+    ],
+    "type": "ChatMessage"
+  },
+  "published": "2018-02-12T14:08:20Z",
+  "to": [
+    "http://2hu.gensokyo/users/marisa"
+  ],
+  "type": "Create"
+}
+```
+
+This setup does not prevent multi-user chats, but these will have to go through
+a `Group`, which will be the recipient of the messages and then `Announce` them
+to the users in the `Group`.
diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index 0273972be..4926572a9 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -78,7 +78,8 @@ defmodule Pleroma.Application do
         ] ++
         elasticsearch_children() ++
         task_children(@mix_env) ++
-        dont_run_in_test(@mix_env)
+        dont_run_in_test(@mix_env) ++
+        shout_child(shout_enabled?())
 
     # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
     # for other strategies and supported options
@@ -93,6 +94,7 @@ defmodule Pleroma.Application do
       end
 
     opts = [strategy: :one_for_one, name: Pleroma.Supervisor, max_restarts: max_restarts]
+    result = Supervisor.start_link(children, opts)
 
     with {:ok, data} <- Supervisor.start_link(children, opts) do
       set_postgres_server_version()
@@ -161,6 +163,10 @@ defmodule Pleroma.Application do
       build_cachex("instances", default_ttl: :timer.hours(24), ttl_interval: 1000, limit: 2500),
       build_cachex("request_signatures", default_ttl: :timer.hours(24 * 30), limit: 3000),
       build_cachex("rel_me", default_ttl: :timer.hours(24 * 30), limit: 300)
+      build_cachex("chat_message_id_idempotency_key",
+        expiration: chat_message_id_idempotency_key_expiration(),
+        limit: 500_000
+      )
     ]
   end
 
@@ -170,6 +176,9 @@ defmodule Pleroma.Application do
   defp idempotency_expiration,
     do: expiration(default: :timer.seconds(6 * 60 * 60), interval: :timer.seconds(60))
 
+  defp chat_message_id_idempotency_key_expiration,
+    do: expiration(default: :timer.minutes(2), interval: :timer.seconds(60))
+
   defp seconds_valid_interval,
     do: :timer.seconds(Config.get!([Pleroma.Captcha, :seconds_valid]))
 
@@ -181,6 +190,8 @@ defmodule Pleroma.Application do
       type: :worker
     }
 
+  defp shout_enabled?, do: Config.get([:shout, :enabled])
+
   defp dont_run_in_test(env) when env in [:test, :benchmark], do: []
 
   defp dont_run_in_test(_) do
@@ -201,6 +212,12 @@ defmodule Pleroma.Application do
   end
 
   @spec task_children(atom()) :: [map()]
+  defp shout_child(true) do
+    [
+      Pleroma.Web.ShoutChannel.ShoutChannelState,
+      {Phoenix.PubSub, [name: Pleroma.PubSub, adapter: Phoenix.PubSub.PG2]}
+    ]
+  end
 
   defp task_children(:test) do
     [
diff --git a/lib/pleroma/chat.ex b/lib/pleroma/chat.ex
new file mode 100644
index 000000000..bacff24b5
--- /dev/null
+++ b/lib/pleroma/chat.ex
@@ -0,0 +1,97 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Chat do
+  use Ecto.Schema
+
+  import Ecto.Changeset
+  import Ecto.Query
+
+  alias Pleroma.Chat
+  alias Pleroma.Repo
+  alias Pleroma.User
+
+  @moduledoc """
+  Chat keeps a reference to ChatMessage conversations between a user and an recipient. The recipient can be a user (for now) or a group (not implemented yet).
+
+  It is a helper only, to make it easy to display a list of chats with other people, ordered by last bump. The actual messages are retrieved by querying the recipients of the ChatMessages.
+  """
+
+  @type t :: %__MODULE__{}
+  @primary_key {:id, FlakeId.Ecto.CompatType, autogenerate: true}
+
+  schema "chats" do
+    belongs_to(:user, User, type: FlakeId.Ecto.CompatType)
+    field(:recipient, :string)
+
+    timestamps()
+  end
+
+  def changeset(struct, params) do
+    struct
+    |> cast(params, [:user_id, :recipient])
+    |> validate_change(:recipient, fn
+      :recipient, recipient ->
+        case User.get_cached_by_ap_id(recipient) do
+          nil -> [recipient: "must be an existing user"]
+          _ -> []
+        end
+    end)
+    |> validate_required([:user_id, :recipient])
+    |> unique_constraint(:user_id, name: :chats_user_id_recipient_index)
+  end
+
+  @spec get_by_user_and_id(User.t(), FlakeId.Ecto.CompatType.t()) ::
+          {:ok, t()} | {:error, :not_found}
+  def get_by_user_and_id(%User{id: user_id}, id) do
+    from(c in __MODULE__,
+      where: c.id == ^id,
+      where: c.user_id == ^user_id
+    )
+    |> Repo.find_resource()
+  end
+
+  @spec get_by_id(FlakeId.Ecto.CompatType.t()) :: t() | nil
+  def get_by_id(id) do
+    Repo.get(__MODULE__, id)
+  end
+
+  @spec get(FlakeId.Ecto.CompatType.t(), String.t()) :: t() | nil
+  def get(user_id, recipient) do
+    Repo.get_by(__MODULE__, user_id: user_id, recipient: recipient)
+  end
+
+  @spec get_or_create(FlakeId.Ecto.CompatType.t(), String.t()) ::
+          {:ok, t()} | {:error, Ecto.Changeset.t()}
+  def get_or_create(user_id, recipient) do
+    %__MODULE__{}
+    |> changeset(%{user_id: user_id, recipient: recipient})
+    |> Repo.insert(
+      # Need to set something, otherwise we get nothing back at all
+      on_conflict: [set: [recipient: recipient]],
+      returning: true,
+      conflict_target: [:user_id, :recipient]
+    )
+  end
+
+  @spec bump_or_create(FlakeId.Ecto.CompatType.t(), String.t()) ::
+          {:ok, t()} | {:error, Ecto.Changeset.t()}
+  def bump_or_create(user_id, recipient) do
+    %__MODULE__{}
+    |> changeset(%{user_id: user_id, recipient: recipient})
+    |> Repo.insert(
+      on_conflict: [set: [updated_at: NaiveDateTime.utc_now()]],
+      returning: true,
+      conflict_target: [:user_id, :recipient]
+    )
+  end
+
+  @spec for_user_query(FlakeId.Ecto.CompatType.t()) :: Ecto.Query.t()
+  def for_user_query(user_id) do
+    from(c in Chat,
+      where: c.user_id == ^user_id,
+      order_by: [desc: c.updated_at]
+    )
+  end
+end
diff --git a/lib/pleroma/chat/message_reference.ex b/lib/pleroma/chat/message_reference.ex
new file mode 100644
index 000000000..89537d155
--- /dev/null
+++ b/lib/pleroma/chat/message_reference.ex
@@ -0,0 +1,117 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Chat.MessageReference do
+  @moduledoc """
+  A reference that builds a relation between an AP chat message that a user can see and whether it has been seen
+  by them, or should be displayed to them. Used to build the chat view that is presented to the user.
+  """
+
+  use Ecto.Schema
+
+  alias Pleroma.Chat
+  alias Pleroma.Object
+  alias Pleroma.Repo
+
+  import Ecto.Changeset
+  import Ecto.Query
+
+  @primary_key {:id, FlakeId.Ecto.Type, autogenerate: true}
+
+  schema "chat_message_references" do
+    belongs_to(:object, Object)
+    belongs_to(:chat, Chat, type: FlakeId.Ecto.CompatType)
+
+    field(:unread, :boolean, default: true)
+
+    timestamps()
+  end
+
+  def changeset(struct, params) do
+    struct
+    |> cast(params, [:object_id, :chat_id, :unread])
+    |> validate_required([:object_id, :chat_id, :unread])
+  end
+
+  def get_by_id(id) do
+    __MODULE__
+    |> Repo.get(id)
+    |> Repo.preload(:object)
+  end
+
+  def delete(cm_ref) do
+    cm_ref
+    |> Repo.delete()
+  end
+
+  def delete_for_object(%{id: object_id}) do
+    from(cr in __MODULE__,
+      where: cr.object_id == ^object_id
+    )
+    |> Repo.delete_all()
+  end
+
+  def for_chat_and_object(%{id: chat_id}, %{id: object_id}) do
+    __MODULE__
+    |> Repo.get_by(chat_id: chat_id, object_id: object_id)
+    |> Repo.preload(:object)
+  end
+
+  def for_chat_query(chat) do
+    from(cr in __MODULE__,
+      where: cr.chat_id == ^chat.id,
+      order_by: [desc: :id],
+      preload: [:object]
+    )
+  end
+
+  def last_message_for_chat(chat) do
+    chat
+    |> for_chat_query()
+    |> limit(1)
+    |> Repo.one()
+  end
+
+  def create(chat, object, unread) do
+    params = %{
+      chat_id: chat.id,
+      object_id: object.id,
+      unread: unread
+    }
+
+    %__MODULE__{}
+    |> changeset(params)
+    |> Repo.insert()
+  end
+
+  def unread_count_for_chat(chat) do
+    chat
+    |> for_chat_query()
+    |> where([cmr], cmr.unread == true)
+    |> Repo.aggregate(:count)
+  end
+
+  def mark_as_read(cm_ref) do
+    cm_ref
+    |> changeset(%{unread: false})
+    |> Repo.update()
+  end
+
+  def set_all_seen_for_chat(chat, last_read_id \\ nil) do
+    query =
+      chat
+      |> for_chat_query()
+      |> exclude(:order_by)
+      |> exclude(:preload)
+      |> where([cmr], cmr.unread == true)
+
+    if last_read_id do
+      query
+      |> where([cmr], cmr.id <= ^last_read_id)
+    else
+      query
+    end
+    |> Repo.update_all(set: [unread: false])
+  end
+end
diff --git a/lib/pleroma/config/deprecation_warnings.ex b/lib/pleroma/config/deprecation_warnings.ex
index 076b4cbf0..c9819d735 100644
--- a/lib/pleroma/config/deprecation_warnings.ex
+++ b/lib/pleroma/config/deprecation_warnings.ex
@@ -179,6 +179,7 @@ defmodule Pleroma.Config.DeprecationWarnings do
       check_activity_expiration_config(),
       check_remote_ip_plug_name(),
       check_uploders_s3_public_endpoint(),
+      check_old_chat_shoutbox(),
       check_quarantined_instances_tuples(),
       check_transparency_exclusions_tuples(),
       check_simple_policy_tuples(),
@@ -337,4 +338,27 @@ defmodule Pleroma.Config.DeprecationWarnings do
       :ok
     end
   end
+
+  @spec check_old_chat_shoutbox() :: :ok | nil
+  def check_old_chat_shoutbox do
+    instance_config = Pleroma.Config.get([:instance])
+    chat_config = Pleroma.Config.get([:chat]) || []
+
+    use_old_config =
+      Keyword.has_key?(instance_config, :chat_limit) or
+        Keyword.has_key?(chat_config, :enabled)
+
+    if use_old_config do
+      Logger.error("""
+      !!!DEPRECATION WARNING!!!
+      Your config is using the old namespace for the Shoutbox configuration. You need to convert to the new namespace. e.g.,
+      \n* `config :pleroma, :chat, enabled` and `config :pleroma, :instance, chat_limit` are now equal to:
+      \n* `config :pleroma, :shout, enabled` and `config :pleroma, :shout, limit`
+      """)
+
+      :error
+    else
+      :ok
+    end
+  end
 end
diff --git a/lib/pleroma/config/transfer_task.ex b/lib/pleroma/config/transfer_task.ex
index 52f6346a5..d4276832a 100644
--- a/lib/pleroma/config/transfer_task.ex
+++ b/lib/pleroma/config/transfer_task.ex
@@ -15,6 +15,7 @@ defmodule Pleroma.Config.TransferTask do
 
   defp reboot_time_keys,
     do: [
+      {:pleroma, :shout},
       {:pleroma, Oban},
       {:pleroma, :rate_limit},
       {:pleroma, :markup},
diff --git a/lib/pleroma/migration_helper/notification_backfill.ex b/lib/pleroma/migration_helper/notification_backfill.ex
index 75d20a402..62b710f82 100644
--- a/lib/pleroma/migration_helper/notification_backfill.ex
+++ b/lib/pleroma/migration_helper/notification_backfill.ex
@@ -3,6 +3,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.MigrationHelper.NotificationBackfill do
+  alias Pleroma.Object
   alias Pleroma.Repo
   alias Pleroma.User
 
@@ -78,5 +79,14 @@ defmodule Pleroma.MigrationHelper.NotificationBackfill do
     end
   end
 
-  defp type_from_activity_object(%{data: %{"type" => "Create"}}), do: "mention"
+  defp type_from_activity_object(%{data: %{"type" => "Create", "object" => %{}}}), do: "mention"
+
+  defp type_from_activity_object(%{data: %{"type" => "Create"}} = activity) do
+    object = Object.get_by_ap_id(activity.data["object"])
+
+    case object && object.data["type"] do
+      "ChatMessage" -> "pleroma:chat_mention"
+      _ -> "mention"
+    end
+  end
 end
diff --git a/lib/pleroma/moderation_log.ex b/lib/pleroma/moderation_log.ex
index b94d53913..241f1abff 100644
--- a/lib/pleroma/moderation_log.ex
+++ b/lib/pleroma/moderation_log.ex
@@ -237,8 +237,20 @@ defmodule Pleroma.ModerationLog do
     insert_log_entry_with_message(%ModerationLog{data: data})
   end
 
+  def insert_log(%{actor: %User{} = actor, action: "chat_message_delete", subject_id: subject_id}) do
+    %ModerationLog{
+      data: %{
+        "actor" => %{"nickname" => actor.nickname},
+        "action" => "chat_message_delete",
+        "subject_id" => subject_id
+      }
+    }
+    |> insert_log_entry_with_message()
+  end
+
   @spec insert_log_entry_with_message(ModerationLog.t()) ::
           {:ok, ModerationLog.t()} | {:error, any}
+		  
   defp insert_log_entry_with_message(entry) do
     entry.data["message"]
     |> put_in(get_log_entry_message(entry))
@@ -544,6 +556,16 @@ defmodule Pleroma.ModerationLog do
     "@#{actor_nickname} updated users: #{users_to_nicknames_string(subjects)}"
   end
 
+  def get_log_entry_message(%ModerationLog{
+        data: %{
+          "actor" => %{"nickname" => actor_nickname},
+          "action" => "chat_message_delete",
+          "subject_id" => subject_id
+        }
+      }) do
+    "@#{actor_nickname} deleted chat message ##{subject_id}"
+  end
+
   def get_log_entry_message(%ModerationLog{
         data: %{
           "actor" => %{"nickname" => actor_nickname},
diff --git a/lib/pleroma/notification.ex b/lib/pleroma/notification.ex
index 3995be01f..d3b99c223 100644
--- a/lib/pleroma/notification.ex
+++ b/lib/pleroma/notification.ex
@@ -68,6 +68,7 @@ defmodule Pleroma.Notification do
     follow_request
     mention
     move
+    pleroma:chat_mention
     pleroma:emoji_reaction
     pleroma:report
     reblog
@@ -463,7 +464,16 @@ defmodule Pleroma.Notification do
     end
   end
 
-  defp type_from_activity_object(%{data: %{"type" => "Create"}}), do: "mention"
+  defp type_from_activity_object(%{data: %{"type" => "Create", "object" => %{}}}), do: "mention"
+
+  defp type_from_activity_object(%{data: %{"type" => "Create"}} = activity) do
+    object = Object.get_by_ap_id(activity.data["object"])
+
+    case object && object.data["type"] do
+      "ChatMessage" -> "pleroma:chat_mention"
+      _ -> "mention"
+    end
+  end
 
   # TODO move to sql, too.
   def create_notification(%Activity{} = activity, %User{} = user, opts \\ []) do
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 7a1e5628e..062f10dae 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -151,6 +151,7 @@ defmodule Pleroma.User do
     field(:also_known_as, {:array, ObjectValidators.ObjectID}, default: [])
     field(:inbox, :string)
     field(:shared_inbox, :string)
+    field(:accepts_chat_messages, :boolean, default: nil)
     field(:last_active_at, :naive_datetime)
     field(:disclose_client, :boolean, default: true)
     field(:pinned_objects, :map, default: %{})
@@ -475,6 +476,7 @@ defmodule Pleroma.User do
         :invisible,
         :actor_type,
         :also_known_as,
+        :accepts_chat_messages,
         :pinned_objects
       ]
     )
@@ -537,6 +539,8 @@ defmodule Pleroma.User do
         :actor_type,
         :disclose_client,
         :status_ttl_days
+        :accepts_chat_messages,
+        :disclose_client
       ]
     )
     |> unique_constraint(:nickname)
@@ -728,6 +732,7 @@ defmodule Pleroma.User do
     bio_limit = Config.get([:instance, :user_bio_length], 5000)
     name_limit = Config.get([:instance, :user_name_length], 100)
     reason_limit = Config.get([:instance, :registration_reason_length], 500)
+    params = Map.put_new(params, :accepts_chat_messages, true)
 
     confirmed? =
       if is_nil(opts[:confirmed]) do
@@ -755,6 +760,7 @@ defmodule Pleroma.User do
       :password,
       :password_confirmation,
       :emoji,
+      :accepts_chat_messages,
       :registration_reason,
       :language
     ])
@@ -865,7 +871,8 @@ defmodule Pleroma.User do
          {:ok, user} <- set_cache(user),
          {:ok, _} <- maybe_send_registration_email(user),
          {:ok, _} <- maybe_send_welcome_email(user),
-         {:ok, _} <- maybe_send_welcome_message(user) do
+         {:ok, _} <- maybe_send_welcome_message(user),
+         {:ok, _} <- maybe_send_welcome_chat_message(user) do
       {:ok, user}
     end
   end
@@ -899,6 +906,15 @@ defmodule Pleroma.User do
     end
   end
 
+  defp maybe_send_welcome_chat_message(user) do
+    if User.WelcomeChatMessage.enabled?() do
+      User.WelcomeChatMessage.post_message(user)
+      {:ok, :enqueued}
+    else
+      {:ok, :noop}
+    end
+  end
+
   defp maybe_send_welcome_email(%User{email: email} = user) when is_binary(email) do
     if User.WelcomeEmail.enabled?() do
       User.WelcomeEmail.send_email(user)
diff --git a/lib/pleroma/user/welcome_chat_message.ex b/lib/pleroma/user/welcome_chat_message.ex
new file mode 100644
index 000000000..0d6690e34
--- /dev/null
+++ b/lib/pleroma/user/welcome_chat_message.ex
@@ -0,0 +1,45 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.User.WelcomeChatMessage do
+  alias Pleroma.Config
+  alias Pleroma.User
+  alias Pleroma.Web.CommonAPI
+
+  @spec enabled?() :: boolean()
+  def enabled?, do: Config.get([:welcome, :chat_message, :enabled], false)
+
+  @spec post_message(User.t()) :: {:ok, Pleroma.Activity.t() | nil}
+  def post_message(user) do
+    [:welcome, :chat_message, :sender_nickname]
+    |> Config.get(nil)
+    |> fetch_sender()
+    |> do_post(user, welcome_message())
+  end
+
+  defp do_post(%User{} = sender, recipient, message)
+       when is_binary(message) do
+    CommonAPI.post_chat_message(
+      sender,
+      recipient,
+      message
+    )
+  end
+
+  defp do_post(_sender, _recipient, _message), do: {:ok, nil}
+
+  defp fetch_sender(nickname) when is_binary(nickname) do
+    with %User{local: true} = user <- User.get_cached_by_nickname(nickname) do
+      user
+    else
+      _ -> nil
+    end
+  end
+
+  defp fetch_sender(_), do: nil
+
+  defp welcome_message do
+    Config.get([:welcome, :chat_message, :message], nil)
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 8e55df0d8..21871847d 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -97,7 +97,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   defp increase_replies_count_if_reply(_create_data), do: :noop
 
-  @object_types ~w[Question Answer Audio Video Event Article Note Page]
+  @object_types ~w[ChatMessage Question Answer Audio Video Event Article Note Page]
   @impl true
   def persist(%{"type" => type} = object, meta) when type in @object_types do
     with {:ok, object} <- Object.create(object) do
@@ -1289,7 +1289,19 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
-  defp exclude_invisible_actors(query, %{type: "Flag"}), do: query
+
+  defp exclude_chat_messages(query, %{include_chat_messages: true}), do: query
+
+  defp exclude_chat_messages(query, _) do
+    if has_named_binding?(query, :object) do
+      from([activity, object: o] in query,
+        where: fragment("not(?->>'type' = ?)", o.data, "ChatMessage")
+      )
+    else
+      query
+    end
+  end
+
   defp exclude_invisible_actors(query, %{invisible_actors: true}), do: query
 
   defp exclude_invisible_actors(query, _opts) do
@@ -1429,6 +1441,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       |> restrict_filtered(opts)
       |> maybe_restrict_deactivated_users(opts)
       |> exclude_poll_votes(opts)
+      |> exclude_chat_messages(opts)
       |> exclude_invisible_actors(opts)
       |> exclude_visibility(opts)
 
@@ -1554,6 +1567,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       end)
 
     is_locked = data["manuallyApprovesFollowers"] || false
+    capabilities = data["capabilities"] || %{}
+    accepts_chat_messages = capabilities["acceptsChatMessages"]
     data = Transmogrifier.maybe_fix_user_object(data)
     is_discoverable = data["discoverable"] || false
     invisible = data["invisible"] || false
@@ -1612,6 +1627,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       shared_inbox: shared_inbox,
       pinned_objects: pinned_objects,
       nickname: nickname
+      accepts_chat_messages: accepts_chat_messages,
+      pinned_objects: pinned_objects
     }
   end
 
diff --git a/lib/pleroma/web/activity_pub/builder.ex b/lib/pleroma/web/activity_pub/builder.ex
index 6d39ad3a8..c2e7993dd 100644
--- a/lib/pleroma/web/activity_pub/builder.ex
+++ b/lib/pleroma/web/activity_pub/builder.ex
@@ -238,6 +238,28 @@ defmodule Pleroma.Web.ActivityPub.Builder do
       Map.put(object, "quoteUri", quote_object.data["id"])
     else
       _ -> object
+	  
+  def chat_message(actor, recipient, content, opts \\ []) do
+    basic = %{
+      "id" => Utils.generate_object_id(),
+      "actor" => actor.ap_id,
+      "type" => "ChatMessage",
+      "to" => [recipient],
+      "content" => content,
+      "published" => DateTime.utc_now() |> DateTime.to_iso8601(),
+      "emoji" => Emoji.Formatter.get_emoji_map(content)
+    }
+
+    case opts[:attachment] do
+      %Object{data: attachment_data} ->
+        {
+          :ok,
+          Map.put(basic, "attachment", attachment_data),
+          []
+        }
+
+      _ ->
+        {:ok, basic, []}
     end
   end
 
diff --git a/lib/pleroma/web/activity_pub/object_validator.ex b/lib/pleroma/web/activity_pub/object_validator.ex
index cb0cc9ed7..924a0baaa 100644
--- a/lib/pleroma/web/activity_pub/object_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validator.ex
@@ -23,6 +23,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
   alias Pleroma.Web.ActivityPub.ObjectValidators.ArticleNotePageValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.AudioVideoValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.BlockValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.ChatMessageValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.CreateChatMessageValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.CreateGenericValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.DeleteValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator
@@ -81,6 +83,21 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
     end
   end
 
+  def validate(
+        %{"type" => "Create", "object" => %{"type" => "ChatMessage"} = object} = create_activity,
+        meta
+      ) do
+    with {:ok, object_data} <- cast_and_apply(object),
+         meta = Keyword.put(meta, :object_data, object_data |> stringify_keys),
+         {:ok, create_activity} <-
+           create_activity
+           |> CreateChatMessageValidator.cast_and_validate(meta)
+           |> Ecto.Changeset.apply_action(:insert) do
+      create_activity = stringify_keys(create_activity)
+      {:ok, create_activity, meta}
+    end
+  end
+
   def validate(
         %{"type" => "Create", "object" => %{"type" => objtype} = object} = create_activity,
         meta
@@ -160,7 +177,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
 
   def validate(%{"type" => type} = object, meta)
       when type in ~w[Accept Reject Follow Update Like EmojiReact Announce
-      Answer] do
+      ChatMessage Answer] do
     validator =
       case type do
         "Accept" -> AcceptRejectValidator
@@ -170,6 +187,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
         "Like" -> LikeValidator
         "EmojiReact" -> EmojiReactValidator
         "Announce" -> AnnounceValidator
+        "ChatMessage" -> ChatMessageValidator
         "Answer" -> AnswerValidator
       end
 
@@ -202,6 +220,10 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
       end
     end)
   end
+	
+  def cast_and_apply(%{"type" => "ChatMessage"} = object) do
+    ChatMessageValidator.cast_and_apply(object)
+  end
 
   def cast_and_apply(%{"type" => "Question"} = object) do
     QuestionValidator.cast_and_apply(object)
diff --git a/lib/pleroma/web/activity_pub/object_validators/chat_message_validator.ex b/lib/pleroma/web/activity_pub/object_validators/chat_message_validator.ex
new file mode 100644
index 000000000..b153156b0
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/object_validators/chat_message_validator.ex
@@ -0,0 +1,129 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.ChatMessageValidator do
+  use Ecto.Schema
+
+  alias Pleroma.EctoType.ActivityPub.ObjectValidators
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ObjectValidators.AttachmentValidator
+
+  import Ecto.Changeset
+  import Pleroma.Web.ActivityPub.Transmogrifier, only: [fix_emoji: 1]
+
+  @primary_key false
+  @derive Jason.Encoder
+
+  embedded_schema do
+    field(:id, ObjectValidators.ObjectID, primary_key: true)
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:type, :string)
+    field(:content, ObjectValidators.SafeText)
+    field(:actor, ObjectValidators.ObjectID)
+    field(:published, ObjectValidators.DateTime)
+    field(:emoji, ObjectValidators.Emoji, default: %{})
+
+    embeds_one(:attachment, AttachmentValidator)
+  end
+
+  def cast_and_apply(data) do
+    data
+    |> cast_data
+    |> apply_action(:insert)
+  end
+
+  def cast_and_validate(data) do
+    data
+    |> cast_data()
+    |> validate_data()
+  end
+
+  def cast_data(data) do
+    %__MODULE__{}
+    |> changeset(data)
+  end
+
+  def fix(data) do
+    data
+    |> fix_emoji()
+    |> fix_attachment()
+    |> Map.put_new("actor", data["attributedTo"])
+  end
+
+  # Throws everything but the first one away
+  def fix_attachment(%{"attachment" => [attachment | _]} = data) do
+    data
+    |> Map.put("attachment", attachment)
+  end
+
+  def fix_attachment(data), do: data
+
+  def changeset(struct, data) do
+    data = fix(data)
+
+    struct
+    |> cast(data, List.delete(__schema__(:fields), :attachment))
+    |> cast_embed(:attachment)
+  end
+
+  defp validate_data(data_cng) do
+    data_cng
+    |> validate_inclusion(:type, ["ChatMessage"])
+    |> validate_required([:id, :actor, :to, :type, :published])
+    |> validate_content_or_attachment()
+    |> validate_length(:to, is: 1)
+    |> validate_length(:content, max: Pleroma.Config.get([:instance, :remote_limit]))
+    |> validate_local_concern()
+  end
+
+  def validate_content_or_attachment(cng) do
+    attachment = get_field(cng, :attachment)
+
+    if attachment do
+      cng
+    else
+      cng
+      |> validate_required([:content])
+    end
+  end
+
+  @doc """
+  Validates the following
+  - If both users are in our system
+  - If at least one of the users in this ChatMessage is a local user
+  - If the recipient is not blocking the actor
+  - If the recipient is explicitly not accepting chat messages
+  """
+  def validate_local_concern(cng) do
+    with actor_ap <- get_field(cng, :actor),
+         {_, %User{} = actor} <- {:find_actor, User.get_cached_by_ap_id(actor_ap)},
+         {_, %User{} = recipient} <-
+           {:find_recipient, User.get_cached_by_ap_id(get_field(cng, :to) |> hd())},
+         {_, false} <- {:not_accepting_chats?, recipient.accepts_chat_messages == false},
+         {_, false} <- {:blocking_actor?, User.blocks?(recipient, actor)},
+         {_, true} <- {:local?, Enum.any?([actor, recipient], & &1.local)} do
+      cng
+    else
+      {:blocking_actor?, true} ->
+        cng
+        |> add_error(:actor, "actor is blocked by recipient")
+
+      {:not_accepting_chats?, true} ->
+        cng
+        |> add_error(:to, "recipient does not accept chat messages")
+
+      {:local?, false} ->
+        cng
+        |> add_error(:actor, "actor and recipient are both remote")
+
+      {:find_actor, _} ->
+        cng
+        |> add_error(:actor, "can't find user")
+
+      {:find_recipient, _} ->
+        cng
+        |> add_error(:to, "can't find user")
+    end
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/object_validators/common_fields.ex b/lib/pleroma/web/activity_pub/object_validators/common_fields.ex
index db28c38ef..6527153b2 100644
--- a/lib/pleroma/web/activity_pub/object_validators/common_fields.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/common_fields.ex
@@ -7,7 +7,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonFields do
   alias Pleroma.Web.ActivityPub.ObjectValidators.AttachmentValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.TagValidator
 
-  # Activities and Objects
+  # Activities and Objects, except (Create)ChatMessage
   defmacro message_fields do
     quote bind_quoted: binding() do
       field(:type, :string)
@@ -39,7 +39,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CommonFields do
     end
   end
 
-  # Basically objects that aren't Answer
+  # Basically objects that aren't ChatMessage and Answer
   defmacro status_object_fields do
     quote bind_quoted: binding() do
       # TODO: Remove actor on objects
diff --git a/lib/pleroma/web/activity_pub/object_validators/create_chat_message_validator.ex b/lib/pleroma/web/activity_pub/object_validators/create_chat_message_validator.ex
new file mode 100644
index 000000000..6551f64ca
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/object_validators/create_chat_message_validator.ex
@@ -0,0 +1,96 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+# NOTES
+# - Can probably be a generic create validator
+# - doesn't embed, will only get the object id
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.CreateChatMessageValidator do
+  use Ecto.Schema
+  alias Pleroma.EctoType.ActivityPub.ObjectValidators
+
+  alias Pleroma.Object
+
+  import Ecto.Changeset
+  import Pleroma.Web.ActivityPub.ObjectValidators.CommonValidations
+
+  @primary_key false
+
+  embedded_schema do
+    quote do
+      unquote do
+        import Elixir.Pleroma.Web.ActivityPub.ObjectValidators.CommonFields
+        activity_fields()
+      end
+    end
+
+    field(:id, ObjectValidators.ObjectID, primary_key: true)
+    field(:type, :string)
+    field(:to, ObjectValidators.Recipients, default: [])
+  end
+
+  def cast_and_apply(data) do
+    data
+    |> cast_data
+    |> apply_action(:insert)
+  end
+
+  def cast_data(data) do
+    cast(%__MODULE__{}, data, __schema__(:fields))
+  end
+
+  def cast_and_validate(data, meta \\ []) do
+    cast_data(data)
+    |> validate_data(meta)
+  end
+
+  defp validate_data(cng, meta) do
+    cng
+    |> validate_required([:id, :actor, :to, :type, :object])
+    |> validate_inclusion(:type, ["Create"])
+    |> validate_actor_presence()
+    |> validate_recipients_match(meta)
+    |> validate_actors_match(meta)
+    |> validate_object_nonexistence()
+  end
+
+  def validate_object_nonexistence(cng) do
+    cng
+    |> validate_change(:object, fn :object, object_id ->
+      if Object.get_cached_by_ap_id(object_id) do
+        [{:object, "The object to create already exists"}]
+      else
+        []
+      end
+    end)
+  end
+
+  def validate_actors_match(cng, meta) do
+    object_actor = meta[:object_data]["actor"]
+
+    cng
+    |> validate_change(:actor, fn :actor, actor ->
+      if actor == object_actor do
+        []
+      else
+        [{:actor, "Actor doesn't match with object actor"}]
+      end
+    end)
+  end
+
+  def validate_recipients_match(cng, meta) do
+    object_recipients = meta[:object_data]["to"] || []
+
+    cng
+    |> validate_change(:to, fn :to, recipients ->
+      activity_set = MapSet.new(recipients)
+      object_set = MapSet.new(object_recipients)
+
+      if MapSet.equal?(activity_set, object_set) do
+        []
+      else
+        [{:to, "Recipients don't match with object recipients"}]
+      end
+    end)
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/object_validators/delete_validator.ex b/lib/pleroma/web/activity_pub/object_validators/delete_validator.ex
index a08e8ebe0..f0c99356e 100644
--- a/lib/pleroma/web/activity_pub/object_validators/delete_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/delete_validator.ex
@@ -48,6 +48,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.DeleteValidator do
     Answer
     Article
     Audio
+    ChatMessage
     Event
     Note
     Page
diff --git a/lib/pleroma/web/activity_pub/side_effects.ex b/lib/pleroma/web/activity_pub/side_effects.ex
index 34617a218..8f6b26aa2 100644
--- a/lib/pleroma/web/activity_pub/side_effects.ex
+++ b/lib/pleroma/web/activity_pub/side_effects.ex
@@ -10,6 +10,8 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
   collection, and so on.
   """
   alias Pleroma.Activity
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
   alias Pleroma.FollowingRelationship
   alias Pleroma.Notification
   alias Pleroma.Object
@@ -26,6 +28,7 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
   require Pleroma.Constants
   require Logger
 
+  @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
   @logger Pleroma.Config.get([:side_effects, :logger], Logger)
 
   @behaviour Pleroma.Web.ActivityPub.SideEffects.Handling
@@ -313,6 +316,8 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
               Object.decrease_replies_count(in_reply_to)
             end
 
+            MessageReference.delete_for_object(deleted_object)
+
             ap_streamer().stream_out(object)
             ap_streamer().stream_out_participations(deleted_object, user)
             :ok
@@ -472,8 +477,43 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
         end
       end
     end
+  end
+	
 
     {:ok, object, meta}
+  def handle_object_creation(%{"type" => "ChatMessage"} = object, _activity, meta) do
+    with {:ok, object, meta} <- Pipeline.common_pipeline(object, meta) do
+      actor = User.get_cached_by_ap_id(object.data["actor"])
+      recipient = User.get_cached_by_ap_id(hd(object.data["to"]))
+
+      streamables =
+        [[actor, recipient], [recipient, actor]]
+        |> Enum.uniq()
+        |> Enum.map(fn [user, other_user] ->
+          if user.local do
+            {:ok, chat} = Chat.bump_or_create(user.id, other_user.ap_id)
+            {:ok, cm_ref} = MessageReference.create(chat, object, user.ap_id != actor.ap_id)
+
+            @cachex.put(
+              :chat_message_id_idempotency_key_cache,
+              cm_ref.id,
+              meta[:idempotency_key]
+            )
+
+            {
+              ["user", "user:pleroma_chat"],
+              {user, %{cm_ref | chat: chat, object: object}}
+            }
+          end
+        end)
+        |> Enum.filter(& &1)
+
+      meta =
+        meta
+        |> add_streamables(streamables)
+
+      {:ok, object, meta}
+    end
   end
 
   def handle_object_creation(%{"type" => "Question"} = object, activity, meta) do
@@ -574,6 +614,13 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
     meta
   end
 
+  defp add_streamables(meta, streamables) do
+    existing = Keyword.get(meta, :streamables, [])
+
+    meta
+    |> Keyword.put(:streamables, streamables ++ existing)
+  end
+
   defp add_notifications(meta, notifications) do
     existing = Keyword.get(meta, :notifications, [])
 
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 2ff0e8a74..2ce2fbae6 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -447,7 +447,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
         %{"type" => "Create", "object" => %{"type" => objtype, "id" => obj_id}} = data,
         options
       )
-      when objtype in ~w{Question Answer Audio Video Event Article Note Page} do
+      when objtype in ~w{Question Answer ChatMessage Audio Video Event Article Note Page} do
     fetch_options = Keyword.put(options, :depth, (options[:depth] || 0) + 1)
 
     object =
@@ -927,6 +927,9 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     Map.put(object, "attributedTo", attributed_to)
   end
 
+  # TODO: Revisit this
+  def prepare_attachments(%{"type" => "ChatMessage"} = object), do: object
+
   def prepare_attachments(object) do
     attachments =
       object
diff --git a/lib/pleroma/web/activity_pub/views/user_view.ex b/lib/pleroma/web/activity_pub/views/user_view.ex
index 310f3ce3e..6314ae07b 100644
--- a/lib/pleroma/web/activity_pub/views/user_view.ex
+++ b/lib/pleroma/web/activity_pub/views/user_view.ex
@@ -81,7 +81,14 @@ defmodule Pleroma.Web.ActivityPub.UserView do
 
     fields = Enum.map(user.fields, &Map.put(&1, "type", "PropertyValue"))
 
-    capabilities = %{}
+    capabilities =
+      if is_boolean(user.accepts_chat_messages) do
+        %{
+          "acceptsChatMessages" => user.accepts_chat_messages
+        }
+      else
+        %{}
+      end
 
     %{
       "id" => user.ap_id,
diff --git a/lib/pleroma/web/admin_api/controllers/admin_api_controller.ex b/lib/pleroma/web/admin_api/controllers/admin_api_controller.ex
index 1d7ac78a0..50aa294f0 100644
--- a/lib/pleroma/web/admin_api/controllers/admin_api_controller.ex
+++ b/lib/pleroma/web/admin_api/controllers/admin_api_controller.ex
@@ -52,6 +52,12 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
     when action in [:list_user_statuses]
   )
 
+  plug(
+    OAuthScopesPlug,
+    %{scopes: ["admin:read:chats"]}
+    when action in [:list_user_chats]
+  )
+
   plug(
     OAuthScopesPlug,
     %{scopes: ["admin:read"]}
@@ -100,6 +106,20 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIController do
     end
   end
 
+  def list_user_chats(%{assigns: %{user: admin}} = conn, %{"nickname" => nickname} = _params) do
+    with %User{id: user_id} <- User.get_cached_by_nickname_or_id(nickname, for: admin) do
+      chats =
+        Pleroma.Chat.for_user_query(user_id)
+        |> Pleroma.Repo.all()
+
+      conn
+      |> put_view(AdminAPI.ChatView)
+      |> render("index.json", chats: chats)
+    else
+      _ -> {:error, :not_found}
+    end
+  end
+
   def tag_users(%{assigns: %{user: admin}} = conn, %{"nicknames" => nicknames, "tags" => tags}) do
     with {:ok, _} <- User.tag(nicknames, tags) do
       ModerationLog.insert_log(%{
diff --git a/lib/pleroma/web/admin_api/controllers/chat_controller.ex b/lib/pleroma/web/admin_api/controllers/chat_controller.ex
new file mode 100644
index 000000000..ff20c8604
--- /dev/null
+++ b/lib/pleroma/web/admin_api/controllers/chat_controller.ex
@@ -0,0 +1,85 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.AdminAPI.ChatController do
+  use Pleroma.Web, :controller
+
+  alias Pleroma.Activity
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.ModerationLog
+  alias Pleroma.Pagination
+  alias Pleroma.Web.AdminAPI
+  alias Pleroma.Web.CommonAPI
+  alias Pleroma.Web.PleromaAPI.Chat.MessageReferenceView
+  alias Pleroma.Web.Plugs.OAuthScopesPlug
+
+  require Logger
+
+  plug(Pleroma.Web.ApiSpec.CastAndValidate)
+
+  plug(
+    OAuthScopesPlug,
+    %{scopes: ["admin:read:chats"]} when action in [:show, :messages]
+  )
+
+  plug(
+    OAuthScopesPlug,
+    %{scopes: ["admin:write:chats"]} when action in [:delete_message]
+  )
+
+  action_fallback(Pleroma.Web.AdminAPI.FallbackController)
+
+  defdelegate open_api_operation(action), to: Pleroma.Web.ApiSpec.Admin.ChatOperation
+
+  def delete_message(%{assigns: %{user: user}} = conn, %{
+        message_id: message_id,
+        id: chat_id
+      }) do
+    with %MessageReference{object: %{data: %{"id" => object_ap_id}}} = cm_ref <-
+           MessageReference.get_by_id(message_id),
+         ^chat_id <- to_string(cm_ref.chat_id),
+         %Activity{id: activity_id} <- Activity.get_create_by_object_ap_id(object_ap_id),
+         {:ok, _} <- CommonAPI.delete(activity_id, user) do
+      ModerationLog.insert_log(%{
+        action: "chat_message_delete",
+        actor: user,
+        subject_id: message_id
+      })
+
+      conn
+      |> put_view(MessageReferenceView)
+      |> render("show.json", chat_message_reference: cm_ref)
+    else
+      _e ->
+        {:error, :could_not_delete}
+    end
+  end
+
+  def messages(conn, %{id: id} = params) do
+    with %Chat{} = chat <- Chat.get_by_id(id) do
+      cm_refs =
+        chat
+        |> MessageReference.for_chat_query()
+        |> Pagination.fetch_paginated(params)
+
+      conn
+      |> put_view(MessageReferenceView)
+      |> render("index.json", chat_message_references: cm_refs)
+    else
+      _ ->
+        conn
+        |> put_status(:not_found)
+        |> json(%{error: "not found"})
+    end
+  end
+
+  def show(conn, %{id: id}) do
+    with %Chat{} = chat <- Chat.get_by_id(id) do
+      conn
+      |> put_view(AdminAPI.ChatView)
+      |> render("show.json", chat: chat)
+    end
+  end
+end
diff --git a/lib/pleroma/web/admin_api/views/chat_view.ex b/lib/pleroma/web/admin_api/views/chat_view.ex
new file mode 100644
index 000000000..2a2015ad1
--- /dev/null
+++ b/lib/pleroma/web/admin_api/views/chat_view.ex
@@ -0,0 +1,30 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.AdminAPI.ChatView do
+  use Pleroma.Web, :view
+
+  alias Pleroma.Chat
+  alias Pleroma.User
+  alias Pleroma.Web.MastodonAPI
+  alias Pleroma.Web.PleromaAPI
+
+  def render("index.json", %{chats: chats} = opts) do
+    render_many(chats, __MODULE__, "show.json", Map.delete(opts, :chats))
+  end
+
+  def render("show.json", %{chat: %Chat{user_id: user_id}} = opts) do
+    user = User.get_by_id(user_id)
+    sender = MastodonAPI.AccountView.render("show.json", user: user, skip_visibility_check: true)
+
+    serialized_chat = PleromaAPI.ChatView.render("show.json", opts)
+
+    serialized_chat
+    |> Map.put(:sender, sender)
+    |> Map.put(:receiver, serialized_chat[:account])
+    |> Map.delete(:account)
+  end
+
+  def render(view, opts), do: PleromaAPI.ChatView.render(view, opts)
+end
diff --git a/lib/pleroma/web/api_spec.ex b/lib/pleroma/web/api_spec.ex
index 26fed1eef..6d9971708 100644
--- a/lib/pleroma/web/api_spec.ex
+++ b/lib/pleroma/web/api_spec.ex
@@ -84,6 +84,7 @@ defmodule Pleroma.Web.ApiSpec do
           %{
             "name" => "Administration",
             "tags" => [
+              "Chat administration",
               "Emoji pack administration",
               "Frontend managment",
               "Instance configuration",
@@ -113,6 +114,7 @@ defmodule Pleroma.Web.ApiSpec do
             ]
           },
           %{"name" => "Instance", "tags" => ["Custom emojis"]},
+          %{"name" => "Messaging", "tags" => ["Chats", "Conversations"]},
           %{
             "name" => "Statuses",
             "tags" => [
diff --git a/lib/pleroma/web/api_spec/operations/account_operation.ex b/lib/pleroma/web/api_spec/operations/account_operation.ex
index 894ad5db0..d156c58e7 100644
--- a/lib/pleroma/web/api_spec/operations/account_operation.ex
+++ b/lib/pleroma/web/api_spec/operations/account_operation.ex
@@ -613,6 +613,11 @@ defmodule Pleroma.Web.ApiSpec.AccountOperation do
           nullable: true,
           description: "Whether manual approval of follow requests is required."
         },
+        accepts_chat_messages: %Schema{
+          allOf: [BooleanLike],
+          nullable: true,
+          description: "Whether the user accepts receiving chat messages."
+        },
         fields_attributes: %Schema{
           nullable: true,
           oneOf: [
diff --git a/lib/pleroma/web/api_spec/operations/admin/chat_operation.ex b/lib/pleroma/web/api_spec/operations/admin/chat_operation.ex
new file mode 100644
index 000000000..57906445e
--- /dev/null
+++ b/lib/pleroma/web/api_spec/operations/admin/chat_operation.ex
@@ -0,0 +1,96 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ApiSpec.Admin.ChatOperation do
+  alias OpenApiSpex.Operation
+  alias Pleroma.Web.ApiSpec.Schemas.Chat
+  alias Pleroma.Web.ApiSpec.Schemas.ChatMessage
+
+  import Pleroma.Web.ApiSpec.Helpers
+
+  def open_api_operation(action) do
+    operation = String.to_existing_atom("#{action}_operation")
+    apply(__MODULE__, operation, [])
+  end
+
+  def delete_message_operation do
+    %Operation{
+      tags: ["Chat administration"],
+      summary: "Delete an individual chat message",
+      operationId: "AdminAPI.ChatController.delete_message",
+      parameters: [
+        Operation.parameter(:id, :path, :string, "The ID of the Chat"),
+        Operation.parameter(:message_id, :path, :string, "The ID of the message")
+      ],
+      responses: %{
+        200 =>
+          Operation.response(
+            "The deleted ChatMessage",
+            "application/json",
+            ChatMessage
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["admin:write:chats"]
+        }
+      ]
+    }
+  end
+
+  def messages_operation do
+    %Operation{
+      tags: ["Chat administration"],
+      summary: "Get chat's messages",
+      operationId: "AdminAPI.ChatController.messages",
+      parameters:
+        [Operation.parameter(:id, :path, :string, "The ID of the Chat")] ++
+          pagination_params(),
+      responses: %{
+        200 =>
+          Operation.response(
+            "The messages in the chat",
+            "application/json",
+            Pleroma.Web.ApiSpec.ChatOperation.chat_messages_response()
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["admin:read:chats"]
+        }
+      ]
+    }
+  end
+
+  def show_operation do
+    %Operation{
+      tags: ["Chat administration"],
+      summary: "Create a chat",
+      operationId: "AdminAPI.ChatController.show",
+      parameters: [
+        Operation.parameter(
+          :id,
+          :path,
+          :string,
+          "The id of the chat",
+          required: true,
+          example: "1234"
+        )
+      ],
+      responses: %{
+        200 =>
+          Operation.response(
+            "The existing chat",
+            "application/json",
+            Chat
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["admin:read"]
+        }
+      ]
+    }
+  end
+end
diff --git a/lib/pleroma/web/api_spec/operations/chat_operation.ex b/lib/pleroma/web/api_spec/operations/chat_operation.ex
new file mode 100644
index 000000000..31fd150de
--- /dev/null
+++ b/lib/pleroma/web/api_spec/operations/chat_operation.ex
@@ -0,0 +1,361 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ApiSpec.ChatOperation do
+  alias OpenApiSpex.Operation
+  alias OpenApiSpex.Schema
+  alias Pleroma.Web.ApiSpec.Schemas.ApiError
+  alias Pleroma.Web.ApiSpec.Schemas.BooleanLike
+  alias Pleroma.Web.ApiSpec.Schemas.Chat
+  alias Pleroma.Web.ApiSpec.Schemas.ChatMessage
+
+  import Pleroma.Web.ApiSpec.Helpers
+
+  @spec open_api_operation(atom) :: Operation.t()
+  def open_api_operation(action) do
+    operation = String.to_existing_atom("#{action}_operation")
+    apply(__MODULE__, operation, [])
+  end
+
+  def mark_as_read_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Mark all messages in the chat as read",
+      operationId: "ChatController.mark_as_read",
+      parameters: [Operation.parameter(:id, :path, :string, "The ID of the Chat")],
+      requestBody: request_body("Parameters", mark_as_read()),
+      responses: %{
+        200 =>
+          Operation.response(
+            "The updated chat",
+            "application/json",
+            Chat
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["write:chats"]
+        }
+      ]
+    }
+  end
+
+  def mark_message_as_read_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Mark a message as read",
+      operationId: "ChatController.mark_message_as_read",
+      parameters: [
+        Operation.parameter(:id, :path, :string, "The ID of the Chat"),
+        Operation.parameter(:message_id, :path, :string, "The ID of the message")
+      ],
+      responses: %{
+        200 =>
+          Operation.response(
+            "The read ChatMessage",
+            "application/json",
+            ChatMessage
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["write:chats"]
+        }
+      ]
+    }
+  end
+
+  def show_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Retrieve a chat",
+      operationId: "ChatController.show",
+      parameters: [
+        Operation.parameter(
+          :id,
+          :path,
+          :string,
+          "The id of the chat",
+          required: true,
+          example: "1234"
+        )
+      ],
+      responses: %{
+        200 =>
+          Operation.response(
+            "The existing chat",
+            "application/json",
+            Chat
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["read"]
+        }
+      ]
+    }
+  end
+
+  def create_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Create a chat",
+      operationId: "ChatController.create",
+      parameters: [
+        Operation.parameter(
+          :id,
+          :path,
+          :string,
+          "The account id of the recipient of this chat",
+          required: true,
+          example: "someflakeid"
+        )
+      ],
+      responses: %{
+        200 =>
+          Operation.response(
+            "The created or existing chat",
+            "application/json",
+            Chat
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["write:chats"]
+        }
+      ]
+    }
+  end
+
+  def index2_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Retrieve list of chats",
+      operationId: "ChatController.index2",
+      parameters: [
+        Operation.parameter(:with_muted, :query, BooleanLike, "Include chats from muted users")
+        | pagination_params()
+      ],
+      responses: %{
+        200 => Operation.response("The chats of the user", "application/json", chats_response())
+      },
+      security: [
+        %{
+          "oAuth" => ["read:chats"]
+        }
+      ]
+    }
+  end
+
+  def messages_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Retrieve chat's messages",
+      operationId: "ChatController.messages",
+      parameters:
+        [Operation.parameter(:id, :path, :string, "The ID of the Chat")] ++
+          pagination_params(),
+      responses: %{
+        200 =>
+          Operation.response(
+            "The messages in the chat",
+            "application/json",
+            chat_messages_response()
+          ),
+        404 => Operation.response("Not Found", "application/json", ApiError)
+      },
+      security: [
+        %{
+          "oAuth" => ["read:chats"]
+        }
+      ]
+    }
+  end
+
+  def post_chat_message_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Post a message to the chat",
+      operationId: "ChatController.post_chat_message",
+      parameters: [
+        Operation.parameter(:id, :path, :string, "The ID of the Chat")
+      ],
+      requestBody: request_body("Parameters", chat_message_create()),
+      responses: %{
+        200 =>
+          Operation.response(
+            "The newly created ChatMessage",
+            "application/json",
+            ChatMessage
+          ),
+        400 => Operation.response("Bad Request", "application/json", ApiError),
+        422 => Operation.response("MRF Rejection", "application/json", ApiError)
+      },
+      security: [
+        %{
+          "oAuth" => ["write:chats"]
+        }
+      ]
+    }
+  end
+
+  def delete_message_operation do
+    %Operation{
+      tags: ["Chats"],
+      summary: "Delete message",
+      operationId: "ChatController.delete_message",
+      parameters: [
+        Operation.parameter(:id, :path, :string, "The ID of the Chat"),
+        Operation.parameter(:message_id, :path, :string, "The ID of the message")
+      ],
+      responses: %{
+        200 =>
+          Operation.response(
+            "The deleted ChatMessage",
+            "application/json",
+            ChatMessage
+          )
+      },
+      security: [
+        %{
+          "oAuth" => ["write:chats"]
+        }
+      ]
+    }
+  end
+
+  def chats_response do
+    %Schema{
+      title: "ChatsResponse",
+      description: "Response schema for multiple Chats",
+      type: :array,
+      items: Chat,
+      example: [
+        %{
+          "account" => %{
+            "pleroma" => %{
+              "is_admin" => false,
+              "is_confirmed" => true,
+              "hide_followers_count" => false,
+              "is_moderator" => false,
+              "hide_favorites" => true,
+              "ap_id" => "https://dontbulling.me/users/lain",
+              "hide_follows_count" => false,
+              "hide_follows" => false,
+              "background_image" => nil,
+              "skip_thread_containment" => false,
+              "hide_followers" => false,
+              "relationship" => %{},
+              "tags" => []
+            },
+            "avatar" =>
+              "https://dontbulling.me/media/065a4dd3c6740dab13ff9c71ec7d240bb9f8be9205c9e7467fb2202117da1e32.jpg",
+            "following_count" => 0,
+            "header_static" => "https://originalpatchou.li/images/banner.png",
+            "source" => %{
+              "sensitive" => false,
+              "note" => "lain",
+              "pleroma" => %{
+                "discoverable" => false,
+                "actor_type" => "Person"
+              },
+              "fields" => []
+            },
+            "statuses_count" => 1,
+            "locked" => false,
+            "created_at" => "2020-04-16T13:40:15.000Z",
+            "display_name" => "lain",
+            "fields" => [],
+            "acct" => "lain@dontbulling.me",
+            "id" => "9u6Qw6TAZANpqokMkK",
+            "emojis" => [],
+            "avatar_static" =>
+              "https://dontbulling.me/media/065a4dd3c6740dab13ff9c71ec7d240bb9f8be9205c9e7467fb2202117da1e32.jpg",
+            "username" => "lain",
+            "followers_count" => 0,
+            "header" => "https://originalpatchou.li/images/banner.png",
+            "bot" => false,
+            "note" => "lain",
+            "url" => "https://dontbulling.me/users/lain"
+          },
+          "id" => "1",
+          "unread" => 2
+        }
+      ]
+    }
+  end
+
+  def chat_messages_response do
+    %Schema{
+      title: "ChatMessagesResponse",
+      description: "Response schema for multiple ChatMessages",
+      type: :array,
+      items: ChatMessage,
+      example: [
+        %{
+          "emojis" => [
+            %{
+              "static_url" => "https://dontbulling.me/emoji/Firefox.gif",
+              "visible_in_picker" => false,
+              "shortcode" => "firefox",
+              "url" => "https://dontbulling.me/emoji/Firefox.gif"
+            }
+          ],
+          "created_at" => "2020-04-21T15:11:46.000Z",
+          "content" => "Check this out :firefox:",
+          "id" => "13",
+          "chat_id" => "1",
+          "account_id" => "someflakeid",
+          "unread" => false
+        },
+        %{
+          "account_id" => "someflakeid",
+          "content" => "Whats' up?",
+          "id" => "12",
+          "chat_id" => "1",
+          "emojis" => [],
+          "created_at" => "2020-04-21T15:06:45.000Z",
+          "unread" => false
+        }
+      ]
+    }
+  end
+
+  def chat_message_create do
+    %Schema{
+      title: "ChatMessageCreateRequest",
+      description: "POST body for creating an chat message",
+      type: :object,
+      properties: %{
+        content: %Schema{
+          type: :string,
+          description: "The content of your message. Optional if media_id is present"
+        },
+        media_id: %Schema{type: :string, description: "The id of an upload"}
+      },
+      example: %{
+        "content" => "Hey wanna buy feet pics?",
+        "media_id" => "134234"
+      }
+    }
+  end
+
+  def mark_as_read do
+    %Schema{
+      title: "MarkAsReadRequest",
+      description: "POST body for marking a number of chat messages as read",
+      type: :object,
+      required: [:last_read_id],
+      properties: %{
+        last_read_id: %Schema{
+          type: :string,
+          description: "The content of your message."
+        }
+      },
+      example: %{
+        "last_read_id" => "abcdef12456"
+      }
+    }
+  end
+end
diff --git a/lib/pleroma/web/api_spec/operations/notification_operation.ex b/lib/pleroma/web/api_spec/operations/notification_operation.ex
index b4a20e5e5..01a886de3 100644
--- a/lib/pleroma/web/api_spec/operations/notification_operation.ex
+++ b/lib/pleroma/web/api_spec/operations/notification_operation.ex
@@ -174,6 +174,7 @@ defmodule Pleroma.Web.ApiSpec.NotificationOperation do
         "reblog",
         "mention",
         "pleroma:emoji_reaction",
+        "pleroma:chat_mention",
         "pleroma:report",
         "move",
         "follow_request",
@@ -189,6 +190,7 @@ defmodule Pleroma.Web.ApiSpec.NotificationOperation do
       - `poll` - A poll you have voted in or created has ended
       - `move` - Someone moved their account
       - `pleroma:emoji_reaction` - Someone reacted with emoji to your status
+      - `pleroma:chat_mention` - Someone mentioned you in a chat message
       - `pleroma:report` - Someone was reported
       """
     }
diff --git a/lib/pleroma/web/api_spec/operations/subscription_operation.ex b/lib/pleroma/web/api_spec/operations/subscription_operation.ex
index a0cf76c32..60a7fb3b0 100644
--- a/lib/pleroma/web/api_spec/operations/subscription_operation.ex
+++ b/lib/pleroma/web/api_spec/operations/subscription_operation.ex
@@ -142,6 +142,11 @@ defmodule Pleroma.Web.ApiSpec.SubscriptionOperation do
                   nullable: true,
                   description: "Receive poll notifications?"
                 },
+                "pleroma:chat_mention": %Schema{
+                  allOf: [BooleanLike],
+                  nullable: true,
+                  description: "Receive chat notifications?"
+                },
                 "pleroma:emoji_reaction": %Schema{
                   allOf: [BooleanLike],
                   nullable: true,
@@ -211,6 +216,11 @@ defmodule Pleroma.Web.ApiSpec.SubscriptionOperation do
                   nullable: true,
                   description: "Receive poll notifications?"
                 },
+                "pleroma:chat_mention": %Schema{
+                  allOf: [BooleanLike],
+                  nullable: true,
+                  description: "Receive chat notifications?"
+                },
                 "pleroma:emoji_reaction": %Schema{
                   allOf: [BooleanLike],
                   nullable: true,
diff --git a/lib/pleroma/web/api_spec/operations/timeline_operation.ex b/lib/pleroma/web/api_spec/operations/timeline_operation.ex
index 3eb6f700b..2a42f4de6 100644
--- a/lib/pleroma/web/api_spec/operations/timeline_operation.ex
+++ b/lib/pleroma/web/api_spec/operations/timeline_operation.ex
@@ -43,7 +43,7 @@ defmodule Pleroma.Web.ApiSpec.TimelineOperation do
       tags: ["Timelines"],
       summary: "Direct timeline",
       description:
-        "View statuses with a “direct” scope addressed to the account. Using this endpoint is discouraged, please use [conversations](#tag/Conversations).",
+        "View statuses with a “direct” scope addressed to the account. Using this endpoint is discouraged, please use [conversations](#tag/Conversations) or [chats](#tag/Chats).",
       parameters: [with_muted_param() | pagination_params()],
       security: [%{"oAuth" => ["read:statuses"]}],
       operationId: "TimelineController.direct",
diff --git a/lib/pleroma/web/api_spec/schemas/account.ex b/lib/pleroma/web/api_spec/schemas/account.ex
index 2693eaceb..566cbd357 100644
--- a/lib/pleroma/web/api_spec/schemas/account.ex
+++ b/lib/pleroma/web/api_spec/schemas/account.ex
@@ -47,6 +47,7 @@ defmodule Pleroma.Web.ApiSpec.Schemas.Account do
             description: "whether the user allows automatically follow moved following accounts"
           },
           background_image: %Schema{type: :string, nullable: true, format: :uri},
+          chat_token: %Schema{type: :string},
           is_confirmed: %Schema{
             type: :boolean,
             description:
@@ -101,6 +102,7 @@ defmodule Pleroma.Web.ApiSpec.Schemas.Account do
             description:
               "A generic map of settings for frontends. Opaque to the backend. Only returned in `verify_credentials` and `update_credentials`"
           },
+          accepts_chat_messages: %Schema{type: :boolean, nullable: true},
           favicon: %Schema{
             type: :string,
             format: :uri,
@@ -179,6 +181,9 @@ defmodule Pleroma.Web.ApiSpec.Schemas.Account do
         "is_admin" => false,
         "is_moderator" => false,
         "skip_thread_containment" => false,
+        "accepts_chat_messages" => true,
+        "chat_token" =>
+          "SFMyNTY.g3QAAAACZAAEZGF0YW0AAAASOXRLaTNlc2JHN09RZ1oyOTIwZAAGc2lnbmVkbgYARNplS3EB.Mb_Iaqew2bN1I1o79B_iP7encmVCpTKC4OtHZRxdjKc",
         "unread_conversation_count" => 0,
         "tags" => [],
         "notification_settings" => %{
diff --git a/lib/pleroma/web/api_spec/schemas/chat.ex b/lib/pleroma/web/api_spec/schemas/chat.ex
new file mode 100644
index 000000000..4afed910d
--- /dev/null
+++ b/lib/pleroma/web/api_spec/schemas/chat.ex
@@ -0,0 +1,75 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ApiSpec.Schemas.Chat do
+  alias OpenApiSpex.Schema
+  alias Pleroma.Web.ApiSpec.Schemas.ChatMessage
+
+  require OpenApiSpex
+
+  OpenApiSpex.schema(%{
+    title: "Chat",
+    description: "Response schema for a Chat",
+    type: :object,
+    properties: %{
+      id: %Schema{type: :string},
+      account: %Schema{type: :object},
+      unread: %Schema{type: :integer},
+      last_message: ChatMessage,
+      updated_at: %Schema{type: :string, format: :"date-time"}
+    },
+    example: %{
+      "account" => %{
+        "pleroma" => %{
+          "is_admin" => false,
+          "is_confirmed" => true,
+          "hide_followers_count" => false,
+          "is_moderator" => false,
+          "hide_favorites" => true,
+          "ap_id" => "https://dontbulling.me/users/lain",
+          "hide_follows_count" => false,
+          "hide_follows" => false,
+          "background_image" => nil,
+          "skip_thread_containment" => false,
+          "hide_followers" => false,
+          "relationship" => %{},
+          "tags" => []
+        },
+        "avatar" =>
+          "https://dontbulling.me/media/065a4dd3c6740dab13ff9c71ec7d240bb9f8be9205c9e7467fb2202117da1e32.jpg",
+        "following_count" => 0,
+        "header_static" => "https://originalpatchou.li/images/banner.png",
+        "source" => %{
+          "sensitive" => false,
+          "note" => "lain",
+          "pleroma" => %{
+            "discoverable" => false,
+            "actor_type" => "Person"
+          },
+          "fields" => []
+        },
+        "statuses_count" => 1,
+        "is_locked" => false,
+        "created_at" => "2020-04-16T13:40:15.000Z",
+        "display_name" => "lain",
+        "fields" => [],
+        "acct" => "lain@dontbulling.me",
+        "id" => "9u6Qw6TAZANpqokMkK",
+        "emojis" => [],
+        "avatar_static" =>
+          "https://dontbulling.me/media/065a4dd3c6740dab13ff9c71ec7d240bb9f8be9205c9e7467fb2202117da1e32.jpg",
+        "username" => "lain",
+        "followers_count" => 0,
+        "header" => "https://originalpatchou.li/images/banner.png",
+        "bot" => false,
+        "note" => "lain",
+        "url" => "https://dontbulling.me/users/lain"
+      },
+      "id" => "1",
+      "unread" => 2,
+      "last_message" => ChatMessage.schema().example(),
+      "updated_at" => "2020-04-21T15:06:45.000Z"
+    }
+  })
+end
diff --git a/lib/pleroma/web/api_spec/schemas/chat_message.ex b/lib/pleroma/web/api_spec/schemas/chat_message.ex
new file mode 100644
index 000000000..348fe95f8
--- /dev/null
+++ b/lib/pleroma/web/api_spec/schemas/chat_message.ex
@@ -0,0 +1,77 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ApiSpec.Schemas.ChatMessage do
+  alias OpenApiSpex.Schema
+  alias Pleroma.Web.ApiSpec.Schemas.Emoji
+
+  require OpenApiSpex
+
+  OpenApiSpex.schema(%{
+    title: "ChatMessage",
+    description: "Response schema for a ChatMessage",
+    nullable: true,
+    type: :object,
+    properties: %{
+      id: %Schema{type: :string},
+      account_id: %Schema{type: :string, description: "The Mastodon API id of the actor"},
+      chat_id: %Schema{type: :string},
+      content: %Schema{type: :string, nullable: true},
+      created_at: %Schema{type: :string, format: :"date-time"},
+      emojis: %Schema{type: :array, items: Emoji},
+      attachment: %Schema{type: :object, nullable: true},
+      card: %Schema{
+        type: :object,
+        nullable: true,
+        description: "Preview card for links included within status content",
+        required: [:url, :title, :description, :type],
+        properties: %{
+          type: %Schema{
+            type: :string,
+            enum: ["link", "photo", "video", "rich"],
+            description: "The type of the preview card"
+          },
+          provider_name: %Schema{
+            type: :string,
+            nullable: true,
+            description: "The provider of the original resource"
+          },
+          provider_url: %Schema{
+            type: :string,
+            format: :uri,
+            description: "A link to the provider of the original resource"
+          },
+          url: %Schema{type: :string, format: :uri, description: "Location of linked resource"},
+          image: %Schema{
+            type: :string,
+            nullable: true,
+            format: :uri,
+            description: "Preview thumbnail"
+          },
+          title: %Schema{type: :string, description: "Title of linked resource"},
+          description: %Schema{type: :string, description: "Description of preview"}
+        }
+      },
+      unread: %Schema{type: :boolean, description: "Whether a message has been marked as read."}
+    },
+    example: %{
+      "account_id" => "someflakeid",
+      "chat_id" => "1",
+      "content" => "hey you again",
+      "created_at" => "2020-04-21T15:06:45.000Z",
+      "card" => nil,
+      "emojis" => [
+        %{
+          "static_url" => "https://dontbulling.me/emoji/Firefox.gif",
+          "visible_in_picker" => false,
+          "shortcode" => "firefox",
+          "url" => "https://dontbulling.me/emoji/Firefox.gif"
+        }
+      ],
+      "id" => "14",
+      "attachment" => nil,
+      "unread" => false
+    }
+  })
+end
diff --git a/lib/pleroma/web/channels/user_socket.ex b/lib/pleroma/web/channels/user_socket.ex
new file mode 100644
index 000000000..043206835
--- /dev/null
+++ b/lib/pleroma/web/channels/user_socket.ex
@@ -0,0 +1,45 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.UserSocket do
+  use Phoenix.Socket
+  alias Pleroma.User
+
+  ## Channels
+  # channel "room:*", Pleroma.Web.RoomChannel
+  channel("chat:*", Pleroma.Web.ShoutChannel)
+
+  # Socket params are passed from the client and can
+  # be used to verify and authenticate a user. After
+  # verification, you can put default assigns into
+  # the socket that will be set for all channels, ie
+  #
+  #     {:ok, assign(socket, :user_id, verified_user_id)}
+  #
+  # To deny connection, return `:error`.
+  #
+  # See `Phoenix.Token` documentation for examples in
+  # performing token verification on connect.
+  def connect(%{"token" => token}, socket) do
+    with true <- Pleroma.Config.get([:shout, :enabled]),
+         {:ok, user_id} <- Phoenix.Token.verify(socket, "user socket", token, max_age: 84_600),
+         %User{} = user <- Pleroma.User.get_cached_by_id(user_id) do
+      {:ok, assign(socket, :user_name, user.nickname)}
+    else
+      _e -> :error
+    end
+  end
+
+  # Socket id's are topics that allow you to identify all sockets for a given user:
+  #
+  #     def id(socket), do: "user_socket:#{socket.assigns.user_id}"
+  #
+  # Would allow you to broadcast a "disconnect" event and terminate
+  # all active sockets and channels for a given user:
+  #
+  #     Pleroma.Web.Endpoint.broadcast("user_socket:#{user.id}", "disconnect", %{})
+  #
+  # Returning `nil` makes this socket anonymous.
+  def id(_socket), do: nil
+end
diff --git a/lib/pleroma/web/common_api.ex b/lib/pleroma/web/common_api.ex
index f1f51acf5..7434487d6 100644
--- a/lib/pleroma/web/common_api.ex
+++ b/lib/pleroma/web/common_api.ex
@@ -5,6 +5,7 @@
 defmodule Pleroma.Web.CommonAPI do
   alias Pleroma.Activity
   alias Pleroma.Conversation.Participation
+  alias Pleroma.Formatter
   alias Pleroma.Object
   alias Pleroma.ThreadMute
   alias Pleroma.User
@@ -29,6 +30,57 @@ defmodule Pleroma.Web.CommonAPI do
     end
   end
 
+  def post_chat_message(%User{} = user, %User{} = recipient, content, opts \\ []) do
+    with maybe_attachment <- opts[:media_id] && Object.get_by_id(opts[:media_id]),
+         :ok <- validate_chat_content_length(content, !!maybe_attachment),
+         {_, {:ok, chat_message_data, _meta}} <-
+           {:build_object,
+            Builder.chat_message(
+              user,
+              recipient.ap_id,
+              content |> format_chat_content,
+              attachment: maybe_attachment
+            )},
+         {_, {:ok, create_activity_data, _meta}} <-
+           {:build_create_activity, Builder.create(user, chat_message_data, [recipient.ap_id])},
+         {_, {:ok, %Activity{} = activity, _meta}} <-
+           {:common_pipeline,
+            Pipeline.common_pipeline(create_activity_data,
+              local: true,
+              idempotency_key: opts[:idempotency_key]
+            )} do
+      {:ok, activity}
+    else
+      {:common_pipeline, {:reject, _} = e} -> e
+      e -> e
+    end
+  end
+
+  defp format_chat_content(nil), do: nil
+
+  defp format_chat_content(content) do
+    {text, _, _} =
+      content
+      |> Formatter.html_escape("text/plain")
+      |> Formatter.linkify()
+      |> (fn {text, mentions, tags} ->
+            {String.replace(text, ~r/\r?\n/, "<br>"), mentions, tags}
+          end).()
+
+    text
+  end
+
+  defp validate_chat_content_length(_, true), do: :ok
+  defp validate_chat_content_length(nil, false), do: {:error, :no_content}
+
+  defp validate_chat_content_length(content, _) do
+    if String.length(content) <= Pleroma.Config.get([:instance, :chat_limit]) do
+      :ok
+    else
+      {:error, :content_too_long}
+    end
+  end
+
   def unblock(blocker, blocked) do
     with {_, %Activity{} = block} <- {:fetch_block, Utils.fetch_latest_block(blocker, blocked)},
          {:ok, unblock_data, _} <- Builder.undo(blocker, block),
diff --git a/lib/pleroma/web/endpoint.ex b/lib/pleroma/web/endpoint.ex
index e3a251ca1..012a4498a 100644
--- a/lib/pleroma/web/endpoint.ex
+++ b/lib/pleroma/web/endpoint.ex
@@ -9,6 +9,7 @@ defmodule Pleroma.Web.Endpoint do
 
   alias Pleroma.Config
 
+  socket("/socket", Pleroma.Web.UserSocket)
   socket("/live", Phoenix.LiveView.Socket)
 
   plug(Pleroma.Web.Plugs.SetLocalePlug)
diff --git a/lib/pleroma/web/mastodon_api/controllers/account_controller.ex b/lib/pleroma/web/mastodon_api/controllers/account_controller.ex
index 678ec3a80..baee4a33d 100644
--- a/lib/pleroma/web/mastodon_api/controllers/account_controller.ex
+++ b/lib/pleroma/web/mastodon_api/controllers/account_controller.ex
@@ -154,10 +154,13 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
 
   @doc "GET /api/v1/accounts/verify_credentials"
   def verify_credentials(%{assigns: %{user: user}} = conn, _) do
+    chat_token = Phoenix.Token.sign(conn, "user socket", user.id)
+
     render(conn, "show.json",
       user: user,
       for: user,
-      with_pleroma_settings: true
+      with_pleroma_settings: true,
+      with_chat_token: chat_token
     )
   end
 
@@ -191,7 +194,8 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
         :show_role,
         :skip_thread_containment,
         :allow_following_move,
-        :also_known_as
+        :also_known_as,
+        :accepts_chat_messages
       ]
       |> Enum.reduce(%{}, fn key, acc ->
         Maps.put_if_present(acc, key, params[key], &{:ok, Params.truthy_param?(&1)})
diff --git a/lib/pleroma/web/mastodon_api/views/account_view.ex b/lib/pleroma/web/mastodon_api/views/account_view.ex
index 190d6ebf2..6073ffd29 100644
--- a/lib/pleroma/web/mastodon_api/views/account_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/account_view.ex
@@ -307,6 +307,7 @@ defmodule Pleroma.Web.MastodonAPI.AccountView do
         relationship: relationship,
         skip_thread_containment: user.skip_thread_containment,
         background_image: image_url(user.background) |> MediaProxy.url(),
+        accepts_chat_messages: user.accepts_chat_messages,
         favicon: favicon
       }
     }
@@ -314,6 +315,7 @@ defmodule Pleroma.Web.MastodonAPI.AccountView do
     |> maybe_put_settings(user, opts[:for], opts)
     |> maybe_put_notification_settings(user, opts[:for])
     |> maybe_put_settings_store(user, opts[:for], opts)
+    |> maybe_put_chat_token(user, opts[:for], opts)
     |> maybe_put_activation_status(user, opts[:for])
     |> maybe_put_follow_requests_count(user, opts[:for])
     |> maybe_put_allow_following_move(user, opts[:for])
@@ -367,6 +369,15 @@ defmodule Pleroma.Web.MastodonAPI.AccountView do
 
   defp maybe_put_settings_store(data, _, _, _), do: data
 
+  defp maybe_put_chat_token(data, %User{id: id}, %User{id: id}, %{
+         with_chat_token: token
+       }) do
+    data
+    |> Kernel.put_in([:pleroma, :chat_token], token)
+  end
+
+  defp maybe_put_chat_token(data, _, _, _), do: data
+
   defp maybe_put_role(data, %User{show_role: true} = user, _) do
     data
     |> Kernel.put_in([:pleroma, :is_admin], user.is_admin)
diff --git a/lib/pleroma/web/mastodon_api/views/instance_view.ex b/lib/pleroma/web/mastodon_api/views/instance_view.ex
index 4fed1af74..6e2702984 100644
--- a/lib/pleroma/web/mastodon_api/views/instance_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/instance_view.ex
@@ -37,6 +37,7 @@ defmodule Pleroma.Web.MastodonAPI.InstanceView do
       background_upload_limit: Keyword.get(instance, :background_upload_limit),
       banner_upload_limit: Keyword.get(instance, :banner_upload_limit),
       background_image: Pleroma.Web.Endpoint.url() <> Keyword.get(instance, :background_image),
+      shout_limit: Config.get([:shout, :limit]),
       description_limit: Keyword.get(instance, :description_limit),
       pleroma: %{
         metadata: %{
diff --git a/lib/pleroma/web/mastodon_api/views/notification_view.ex b/lib/pleroma/web/mastodon_api/views/notification_view.ex
index e527ff608..66ea59cef 100644
--- a/lib/pleroma/web/mastodon_api/views/notification_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/notification_view.ex
@@ -6,7 +6,9 @@ defmodule Pleroma.Web.MastodonAPI.NotificationView do
   use Pleroma.Web, :view
 
   alias Pleroma.Activity
+  alias Pleroma.Chat.MessageReference
   alias Pleroma.Notification
+  alias Pleroma.Object
   alias Pleroma.User
   alias Pleroma.UserRelationship
   alias Pleroma.Web.AdminAPI.Report
@@ -16,6 +18,7 @@ defmodule Pleroma.Web.MastodonAPI.NotificationView do
   alias Pleroma.Web.MastodonAPI.AccountView
   alias Pleroma.Web.MastodonAPI.NotificationView
   alias Pleroma.Web.MastodonAPI.StatusView
+  alias Pleroma.Web.PleromaAPI.Chat.MessageReferenceView
 
   defp object_id_for(%{data: %{"object" => %{"id" => id}}}) when is_binary(id), do: id
 
@@ -125,6 +128,9 @@ defmodule Pleroma.Web.MastodonAPI.NotificationView do
         |> put_status(parent_activity_fn.(), reading_user, status_render_opts)
         |> put_emoji(activity)
 
+      "pleroma:chat_mention" ->
+        put_chat_message(response, activity, reading_user, status_render_opts)
+
       "pleroma:report" ->
         put_report(response, activity)
 
@@ -145,6 +151,17 @@ defmodule Pleroma.Web.MastodonAPI.NotificationView do
     |> Map.put(:emoji_url, MediaProxy.url(Pleroma.Emoji.emoji_url(activity.data)))
   end
 
+  defp put_chat_message(response, activity, reading_user, opts) do
+    object = Object.normalize(activity, fetch: false)
+    author = User.get_cached_by_ap_id(object.data["actor"])
+    chat = Pleroma.Chat.get(reading_user.id, author.ap_id)
+    cm_ref = MessageReference.for_chat_and_object(chat, object)
+    render_opts = Map.merge(opts, %{for: reading_user, chat_message_reference: cm_ref})
+    chat_message_render = MessageReferenceView.render("show.json", render_opts)
+
+    Map.put(response, :chat_message, chat_message_render)
+  end
+
   defp put_status(response, activity, reading_user, opts) do
     status_render_opts = Map.merge(opts, %{activity: activity, for: reading_user})
     status_render = StatusView.render("show.json", status_render_opts)
diff --git a/lib/pleroma/web/pleroma_api/controllers/chat_controller.ex b/lib/pleroma/web/pleroma_api/controllers/chat_controller.ex
new file mode 100644
index 000000000..669d50132
--- /dev/null
+++ b/lib/pleroma/web/pleroma_api/controllers/chat_controller.ex
@@ -0,0 +1,188 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+defmodule Pleroma.Web.PleromaAPI.ChatController do
+  use Pleroma.Web, :controller
+
+  import Pleroma.Web.ControllerHelper, only: [add_link_headers: 2]
+
+  alias Pleroma.Activity
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.Object
+  alias Pleroma.Pagination
+  alias Pleroma.Repo
+  alias Pleroma.User
+  alias Pleroma.Web.CommonAPI
+  alias Pleroma.Web.PleromaAPI.Chat.MessageReferenceView
+  alias Pleroma.Web.Plugs.OAuthScopesPlug
+
+  import Ecto.Query
+
+  action_fallback(Pleroma.Web.MastodonAPI.FallbackController)
+
+  plug(
+    OAuthScopesPlug,
+    %{scopes: ["write:chats"]}
+    when action in [
+           :post_chat_message,
+           :create,
+           :mark_as_read,
+           :mark_message_as_read,
+           :delete_message
+         ]
+  )
+
+  plug(
+    OAuthScopesPlug,
+    %{scopes: ["read:chats"]} when action in [:messages, :index, :index2, :show]
+  )
+
+  plug(Pleroma.Web.ApiSpec.CastAndValidate)
+
+  defdelegate open_api_operation(action), to: Pleroma.Web.ApiSpec.ChatOperation
+
+  def delete_message(%{assigns: %{user: %{id: user_id} = user}} = conn, %{
+        message_id: message_id,
+        id: chat_id
+      }) do
+    with %MessageReference{} = cm_ref <-
+           MessageReference.get_by_id(message_id),
+         ^chat_id <- to_string(cm_ref.chat_id),
+         %Chat{user_id: ^user_id} <- Chat.get_by_id(chat_id),
+         {:ok, _} <- remove_or_delete(cm_ref, user) do
+      conn
+      |> put_view(MessageReferenceView)
+      |> render("show.json", chat_message_reference: cm_ref)
+    else
+      _e ->
+        {:error, :could_not_delete}
+    end
+  end
+
+  defp remove_or_delete(
+         %{object: %{data: %{"actor" => actor, "id" => id}}},
+         %{ap_id: actor} = user
+       ) do
+    with %Activity{} = activity <- Activity.get_create_by_object_ap_id(id) do
+      CommonAPI.delete(activity.id, user)
+    end
+  end
+
+  defp remove_or_delete(cm_ref, _), do: MessageReference.delete(cm_ref)
+
+  def post_chat_message(
+        %{body_params: params, assigns: %{user: user}} = conn,
+        %{id: id}
+      ) do
+    with {:ok, chat} <- Chat.get_by_user_and_id(user, id),
+         %User{} = recipient <- User.get_cached_by_ap_id(chat.recipient),
+         {:ok, activity} <-
+           CommonAPI.post_chat_message(user, recipient, params[:content],
+             media_id: params[:media_id],
+             idempotency_key: idempotency_key(conn)
+           ),
+         message <- Object.normalize(activity, fetch: false),
+         cm_ref <- MessageReference.for_chat_and_object(chat, message) do
+      conn
+      |> put_view(MessageReferenceView)
+      |> render("show.json", chat_message_reference: cm_ref)
+    else
+      {:reject, message} ->
+        conn
+        |> put_status(:unprocessable_entity)
+        |> json(%{error: message})
+
+      {:error, message} ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: message})
+    end
+  end
+
+  def mark_message_as_read(
+        %{assigns: %{user: %{id: user_id}}} = conn,
+        %{id: chat_id, message_id: message_id}
+      ) do
+    with %MessageReference{} = cm_ref <- MessageReference.get_by_id(message_id),
+         ^chat_id <- to_string(cm_ref.chat_id),
+         %Chat{user_id: ^user_id} <- Chat.get_by_id(chat_id),
+         {:ok, cm_ref} <- MessageReference.mark_as_read(cm_ref) do
+      conn
+      |> put_view(MessageReferenceView)
+      |> render("show.json", chat_message_reference: cm_ref)
+    end
+  end
+
+  def mark_as_read(
+        %{body_params: %{last_read_id: last_read_id}, assigns: %{user: user}} = conn,
+        %{id: id}
+      ) do
+    with {:ok, chat} <- Chat.get_by_user_and_id(user, id),
+         {_n, _} <- MessageReference.set_all_seen_for_chat(chat, last_read_id) do
+      render(conn, "show.json", chat: chat)
+    end
+  end
+
+  def messages(%{assigns: %{user: user}} = conn, %{id: id} = params) do
+    with {:ok, chat} <- Chat.get_by_user_and_id(user, id) do
+      chat_message_refs =
+        chat
+        |> MessageReference.for_chat_query()
+        |> Pagination.fetch_paginated(params)
+
+      conn
+      |> add_link_headers(chat_message_refs)
+      |> put_view(MessageReferenceView)
+      |> render("index.json", chat_message_references: chat_message_refs)
+    end
+  end
+
+  def index(%{assigns: %{user: user}} = conn, params) do
+    chats =
+      index_query(user, params)
+      |> Repo.all()
+
+    render(conn, "index.json", chats: chats)
+  end
+
+  def index2(%{assigns: %{user: user}} = conn, params) do
+    chats =
+      index_query(user, params)
+      |> Pagination.fetch_paginated(params)
+
+    conn
+    |> add_link_headers(chats)
+    |> render("index.json", chats: chats)
+  end
+
+  defp index_query(%{id: user_id} = user, params) do
+    exclude_users =
+      User.cached_blocked_users_ap_ids(user) ++
+        if params[:with_muted], do: [], else: User.cached_muted_users_ap_ids(user)
+
+    user_id
+    |> Chat.for_user_query()
+    |> where([c], c.recipient not in ^exclude_users)
+  end
+
+  def create(%{assigns: %{user: user}} = conn, %{id: id}) do
+    with %User{ap_id: recipient} <- User.get_cached_by_id(id),
+         {:ok, %Chat{} = chat} <- Chat.get_or_create(user.id, recipient) do
+      render(conn, "show.json", chat: chat)
+    end
+  end
+
+  def show(%{assigns: %{user: user}} = conn, %{id: id}) do
+    with {:ok, chat} <- Chat.get_by_user_and_id(user, id) do
+      render(conn, "show.json", chat: chat)
+    end
+  end
+
+  defp idempotency_key(conn) do
+    case get_req_header(conn, "idempotency-key") do
+      [key] -> key
+      _ -> nil
+    end
+  end
+end
diff --git a/lib/pleroma/web/pleroma_api/views/chat/message_reference_view.ex b/lib/pleroma/web/pleroma_api/views/chat/message_reference_view.ex
new file mode 100644
index 000000000..2e4355992
--- /dev/null
+++ b/lib/pleroma/web/pleroma_api/views/chat/message_reference_view.ex
@@ -0,0 +1,63 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.PleromaAPI.Chat.MessageReferenceView do
+  use Pleroma.Web, :view
+
+  alias Pleroma.Maps
+  alias Pleroma.User
+  alias Pleroma.Web.CommonAPI.Utils
+  alias Pleroma.Web.MastodonAPI.StatusView
+
+  @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
+
+  def render(
+        "show.json",
+        %{
+          chat_message_reference: %{
+            id: id,
+            object: %{data: chat_message} = object,
+            chat_id: chat_id,
+            unread: unread
+          }
+        }
+      ) do
+    %{
+      id: id |> to_string(),
+      content: chat_message["content"],
+      chat_id: chat_id |> to_string(),
+      account_id: User.get_cached_by_ap_id(chat_message["actor"]).id,
+      created_at: Utils.to_masto_date(chat_message["published"]),
+      emojis: StatusView.build_emojis(chat_message["emoji"]),
+      attachment:
+        chat_message["attachment"] &&
+          StatusView.render("attachment.json", attachment: chat_message["attachment"]),
+      unread: unread,
+      card:
+        StatusView.render(
+          "card.json",
+          Pleroma.Web.RichMedia.Helpers.fetch_data_for_object(object)
+        )
+    }
+    |> put_idempotency_key()
+  end
+
+  def render("index.json", opts) do
+    render_many(
+      opts[:chat_message_references],
+      __MODULE__,
+      "show.json",
+      Map.put(opts, :as, :chat_message_reference)
+    )
+  end
+
+  defp put_idempotency_key(data) do
+    with {:ok, idempotency_key} <- @cachex.get(:chat_message_id_idempotency_key_cache, data.id) do
+      data
+      |> Maps.put_if_present(:idempotency_key, idempotency_key)
+    else
+      _ -> data
+    end
+  end
+end
diff --git a/lib/pleroma/web/pleroma_api/views/chat_view.ex b/lib/pleroma/web/pleroma_api/views/chat_view.ex
new file mode 100644
index 000000000..3794818a7
--- /dev/null
+++ b/lib/pleroma/web/pleroma_api/views/chat_view.ex
@@ -0,0 +1,44 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.PleromaAPI.ChatView do
+  use Pleroma.Web, :view
+
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.User
+  alias Pleroma.Web.CommonAPI.Utils
+  alias Pleroma.Web.MastodonAPI.AccountView
+  alias Pleroma.Web.PleromaAPI.Chat.MessageReferenceView
+
+  def render("show.json", %{chat: %Chat{} = chat} = opts) do
+    recipient = User.get_cached_by_ap_id(chat.recipient)
+    last_message = opts[:last_message] || MessageReference.last_message_for_chat(chat)
+    account_view_opts = account_view_opts(opts, recipient)
+
+    %{
+      id: chat.id |> to_string(),
+      account: AccountView.render("show.json", account_view_opts),
+      unread: MessageReference.unread_count_for_chat(chat),
+      last_message:
+        last_message &&
+          MessageReferenceView.render("show.json", chat_message_reference: last_message),
+      updated_at: Utils.to_masto_date(chat.updated_at)
+    }
+  end
+
+  def render("index.json", %{chats: chats} = opts) do
+    render_many(chats, __MODULE__, "show.json", Map.delete(opts, :chats))
+  end
+
+  defp account_view_opts(opts, recipient) do
+    account_view_opts = Map.put(opts, :user, recipient)
+
+    if Map.has_key?(account_view_opts, :for) do
+      account_view_opts
+    else
+      Map.put(account_view_opts, :skip_visibility_check, true)
+    end
+  end
+end
diff --git a/lib/pleroma/web/push/impl.ex b/lib/pleroma/web/push/impl.ex
index e103cafc2..9945346ad 100644
--- a/lib/pleroma/web/push/impl.ex
+++ b/lib/pleroma/web/push/impl.ex
@@ -124,6 +124,13 @@ defmodule Pleroma.Web.Push.Impl do
 
   def format_body(activity, actor, object, mastodon_type \\ nil)
 
+  def format_body(_activity, actor, %{data: %{"type" => "ChatMessage"} = data}, _) do
+    case data["content"] do
+      nil -> "@#{actor.nickname}: (Attachment)"
+      content -> "@#{actor.nickname}: #{Utils.scrub_html_and_truncate(content, 80)}"
+    end
+  end
+
   def format_body(
         %{activity: %{data: %{"type" => "Create"}}},
         actor,
@@ -190,6 +197,7 @@ defmodule Pleroma.Web.Push.Impl do
       "reblog" -> "New Repeat"
       "favourite" -> "New Favorite"
       "update" -> "New Update"
+      "pleroma:chat_mention" -> "New Chat Message"
       "pleroma:emoji_reaction" -> "New Reaction"
       type -> "New #{String.capitalize(type || "event")}"
     end
diff --git a/lib/pleroma/web/push/subscription.ex b/lib/pleroma/web/push/subscription.ex
index b063b103f..35bf2e223 100644
--- a/lib/pleroma/web/push/subscription.ex
+++ b/lib/pleroma/web/push/subscription.ex
@@ -26,7 +26,7 @@ defmodule Pleroma.Web.Push.Subscription do
   end
 
   # credo:disable-for-next-line Credo.Check.Readability.MaxLineLength
-  @supported_alert_types ~w[follow favourite mention reblog poll pleroma:emoji_reaction]a
+  @supported_alert_types ~w[follow favourite mention reblog poll pleroma:chat_mention pleroma:emoji_reaction]a
 
   defp alerts(%{data: %{alerts: alerts}}) do
     alerts = Map.take(alerts, @supported_alert_types)
diff --git a/lib/pleroma/web/router.ex b/lib/pleroma/web/router.ex
index faaf3d679..79cf820a5 100644
--- a/lib/pleroma/web/router.ex
+++ b/lib/pleroma/web/router.ex
@@ -256,8 +256,12 @@ defmodule Pleroma.Web.Router do
     patch("/users/:nickname/credentials", AdminAPIController, :update_user_credentials)
 
     get("/users/:nickname/statuses", AdminAPIController, :list_user_statuses)
+    get("/users/:nickname/chats", AdminAPIController, :list_user_chats)
 
     get("/statuses", StatusController, :index)
+
+    get("/chats/:id", ChatController, :show)
+    get("/chats/:id/messages", ChatController, :messages)
   end
 
   # AdminAPI: admins and mods (staff) can perform these actions
@@ -297,6 +301,8 @@ defmodule Pleroma.Web.Router do
 
     post("/reload_emoji", AdminAPIController, :reload_emoji)
     get("/stats", AdminAPIController, :stats)
+
+    delete("/chats/:id/messages/:message_id", ChatController, :delete_message)
   end
 
   scope "/api/v1/pleroma/emoji", Pleroma.Web.PleromaAPI do
@@ -425,6 +431,14 @@ defmodule Pleroma.Web.Router do
     scope [] do
       pipe_through(:authenticated_api)
 
+      post("/chats/by-account-id/:id", ChatController, :create)
+      get("/chats/:id", ChatController, :show)
+      get("/chats/:id/messages", ChatController, :messages)
+      post("/chats/:id/messages", ChatController, :post_chat_message)
+      delete("/chats/:id/messages/:message_id", ChatController, :delete_message)
+      post("/chats/:id/read", ChatController, :mark_as_read)
+      post("/chats/:id/messages/:message_id/read", ChatController, :mark_message_as_read)
+
       get("/conversations/:id/statuses", ConversationController, :statuses)
       get("/conversations/:id", ConversationController, :show)
       post("/conversations/read", ConversationController, :mark_as_read)
@@ -490,6 +504,11 @@ defmodule Pleroma.Web.Router do
       FrontendSettingsController,
       :delete_profile
     )
+  scope "/api/v2/pleroma", Pleroma.Web.PleromaAPI do
+    scope [] do
+      pipe_through(:authenticated_api)
+      get("/chats", ChatController, :index2)
+    end
   end
 
   scope "/api/v1", Pleroma.Web.MastodonAPI do
diff --git a/lib/pleroma/web/shout_channel.ex b/lib/pleroma/web/shout_channel.ex
new file mode 100644
index 000000000..17caecb1a
--- /dev/null
+++ b/lib/pleroma/web/shout_channel.ex
@@ -0,0 +1,59 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ShoutChannel do
+  use Phoenix.Channel
+
+  alias Pleroma.User
+  alias Pleroma.Web.MastodonAPI.AccountView
+  alias Pleroma.Web.ShoutChannel.ShoutChannelState
+
+  def join("chat:public", _message, socket) do
+    send(self(), :after_join)
+    {:ok, socket}
+  end
+
+  def handle_info(:after_join, socket) do
+    push(socket, "messages", %{messages: ShoutChannelState.messages()})
+    {:noreply, socket}
+  end
+
+  def handle_in("new_msg", %{"text" => text}, %{assigns: %{user_name: user_name}} = socket) do
+    text = String.trim(text)
+
+    if String.length(text) in 1..Pleroma.Config.get([:shout, :limit]) do
+      author = User.get_cached_by_nickname(user_name)
+      author_json = AccountView.render("show.json", user: author, skip_visibility_check: true)
+
+      message = ShoutChannelState.add_message(%{text: text, author: author_json})
+
+      broadcast!(socket, "new_msg", message)
+    end
+
+    {:noreply, socket}
+  end
+end
+
+defmodule Pleroma.Web.ShoutChannel.ShoutChannelState do
+  use Agent
+
+  @max_messages 20
+
+  def start_link(_) do
+    Agent.start_link(fn -> %{max_id: 1, messages: []} end, name: __MODULE__)
+  end
+
+  def add_message(message) do
+    Agent.get_and_update(__MODULE__, fn state ->
+      id = state[:max_id] + 1
+      message = Map.put(message, "id", id)
+      messages = [message | state[:messages]] |> Enum.take(@max_messages)
+      {message, %{max_id: id, messages: messages}}
+    end)
+  end
+
+  def messages do
+    Agent.get(__MODULE__, fn state -> state[:messages] |> Enum.reverse() end)
+  end
+end
diff --git a/lib/pleroma/web/streamer.ex b/lib/pleroma/web/streamer.ex
index f009fbd9e..023e36ea3 100644
--- a/lib/pleroma/web/streamer.ex
+++ b/lib/pleroma/web/streamer.ex
@@ -6,6 +6,7 @@ defmodule Pleroma.Web.Streamer do
   require Logger
 
   alias Pleroma.Activity
+  alias Pleroma.Chat.MessageReference
   alias Pleroma.Config
   alias Pleroma.Conversation.Participation
   alias Pleroma.Notification
@@ -25,7 +26,7 @@ defmodule Pleroma.Web.Streamer do
   def registry, do: @registry
 
   @public_streams ["public", "public:local", "public:media", "public:local:media"]
-  @user_streams ["user", "user:notification", "direct"]
+  @user_streams ["user", "user:notification", "direct", "user:pleroma_chat"]
 
   @doc "Expands and authorizes a stream, and registers the process for streaming."
   @spec get_topic_and_add_socket(
@@ -246,6 +247,19 @@ defmodule Pleroma.Web.Streamer do
     end)
   end
 
+  defp do_stream(topic, {user, %MessageReference{} = cm_ref})
+       when topic in ["user", "user:pleroma_chat"] do
+    topic = "#{topic}:#{user.id}"
+
+    text = StreamerView.render("chat_update.json", %{chat_message_reference: cm_ref})
+
+    Registry.dispatch(@registry, topic, fn list ->
+      Enum.each(list, fn {pid, _auth} ->
+        send(pid, {:text, text})
+      end)
+    end)
+  end
+
   defp do_stream("user", item) do
     Logger.debug("Trying to push to users")
 
diff --git a/lib/pleroma/web/views/streamer_view.ex b/lib/pleroma/web/views/streamer_view.ex
index eba3d96ec..64870061f 100644
--- a/lib/pleroma/web/views/streamer_view.ex
+++ b/lib/pleroma/web/views/streamer_view.ex
@@ -73,7 +73,32 @@ defmodule Pleroma.Web.StreamerView do
 
   def render("status_update.json", %Activity{} = activity, topic) do
     activity = Activity.get_create_by_object_ap_id_with_object(activity.object.data["id"])
+  end
 
+  def render("chat_update.json", %{chat_message_reference: cm_ref}) do
+    # Explicitly giving the cmr for the object here, so we don't accidentally
+    # send a later 'last_message' that was inserted between inserting this and
+    # streaming it out
+    #
+    # It also contains the chat with a cache of the correct unread count
+    Logger.debug("Trying to stream out #{inspect(cm_ref)}")
+
+    representation =
+      Pleroma.Web.PleromaAPI.ChatView.render(
+        "show.json",
+        %{last_message: cm_ref, chat: cm_ref.chat}
+      )
+
+    %{
+      event: "pleroma:chat_update",
+      payload:
+        representation
+        |> Jason.encode!()
+    }
+    |> Jason.encode!()
+  end
+
+  def render("follow_relationships_update.json", item) do
     %{
       stream: [topic],
       event: "status.update",
diff --git a/test/fixtures/mewmew_no_name.json b/test/fixtures/mewmew_no_name.json
index 08e245254..532d4cf70 100644
--- a/test/fixtures/mewmew_no_name.json
+++ b/test/fixtures/mewmew_no_name.json
@@ -8,6 +8,7 @@
    ],
    "attachment" : [],
    "capabilities" : {
+      "acceptsChatMessages" : true
    },
    "discoverable" : false,
    "endpoints" : {
diff --git a/test/mix/tasks/pleroma/config_test.exs b/test/mix/tasks/pleroma/config_test.exs
index 15ffe0ce6..781be8228 100644
--- a/test/mix/tasks/pleroma/config_test.exs
+++ b/test/mix/tasks/pleroma/config_test.exs
@@ -124,6 +124,7 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
           notify_email: "noreply@example.com",
           description: "A Pleroma instance, an alternative fediverse server",
           limit: 5_000,
+          chat_limit: 5_000,
           remote_limit: 100_000,
           upload_limit: 16_000_000,
           avatar_upload_limit: 2_000_000,
@@ -183,7 +184,7 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
       {:ok, file} = File.read(temp_file)
 
       assert file ==
-               "import Config\n\nconfig :pleroma, :instance,\n  name: \"Pleroma\",\n  email: \"example@example.com\",\n  notify_email: \"noreply@example.com\",\n  description: \"A Pleroma instance, an alternative fediverse server\",\n  limit: 5000,\n  remote_limit: 100_000,\n  upload_limit: 16_000_000,\n  avatar_upload_limit: 2_000_000,\n  background_upload_limit: 4_000_000,\n  banner_upload_limit: 4_000_000,\n  poll_limits: %{\n    max_expiration: 31_536_000,\n    max_option_chars: 200,\n    max_options: 20,\n    min_expiration: 0\n  },\n  registrations_open: true,\n  federating: true,\n  federation_incoming_replies_max_depth: 100,\n  federation_reachability_timeout_days: 7,\n  federation_publisher_modules: [Pleroma.Web.ActivityPub.Publisher],\n  allow_relay: true,\n  public: true,\n  quarantined_instances: [],\n  managed_config: true,\n  static_dir: \"instance/static/\",\n  allowed_post_formats: [\"text/plain\", \"text/html\", \"text/markdown\", \"text/bbcode\"],\n  autofollowed_nicknames: [],\n  max_pinned_statuses: 1,\n  attachment_links: false,\n  max_report_comment_size: 1000,\n  safe_dm_mentions: false,\n  healthcheck: false,\n  remote_post_retention_days: 90,\n  skip_thread_containment: true,\n  limit_to_local_content: :unauthenticated,\n  user_bio_length: 5000,\n  user_name_length: 100,\n  max_account_fields: 10,\n  max_remote_account_fields: 20,\n  account_field_name_length: 512,\n  account_field_value_length: 2048,\n  external_user_synchronization: true,\n  extended_nickname_format: true,\n  multi_factor_authentication: [\n    totp: [digits: 6, period: 30],\n    backup_codes: [number: 2, length: 6]\n  ]\n"
+               "import Config\n\nconfig :pleroma, :instance,\n  name: \"Pleroma\",\n  email: \"example@example.com\",\n  notify_email: \"noreply@example.com\",\n  description: \"A Pleroma instance, an alternative fediverse server\",\n  limit: 5000,\n  chat_limit: 5000,\n  remote_limit: 100_000,\n  upload_limit: 16_000_000,\n  avatar_upload_limit: 2_000_000,\n  background_upload_limit: 4_000_000,\n  banner_upload_limit: 4_000_000,\n  poll_limits: %{\n    max_expiration: 31_536_000,\n    max_option_chars: 200,\n    max_options: 20,\n    min_expiration: 0\n  },\n  registrations_open: true,\n  federating: true,\n  federation_incoming_replies_max_depth: 100,\n  federation_reachability_timeout_days: 7,\n  federation_publisher_modules: [Pleroma.Web.ActivityPub.Publisher],\n  allow_relay: true,\n  public: true,\n  quarantined_instances: [],\n  managed_config: true,\n  static_dir: \"instance/static/\",\n  allowed_post_formats: [\"text/plain\", \"text/html\", \"text/markdown\", \"text/bbcode\"],\n  autofollowed_nicknames: [],\n  max_pinned_statuses: 1,\n  attachment_links: false,\n  max_report_comment_size: 1000,\n  safe_dm_mentions: false,\n  healthcheck: false,\n  remote_post_retention_days: 90,\n  skip_thread_containment: true,\n  limit_to_local_content: :unauthenticated,\n  user_bio_length: 5000,\n  user_name_length: 100,\n  max_account_fields: 10,\n  max_remote_account_fields: 20,\n  account_field_name_length: 512,\n  account_field_value_length: 2048,\n  external_user_synchronization: true,\n  extended_nickname_format: true,\n  multi_factor_authentication: [\n    totp: [digits: 6, period: 30],\n    backup_codes: [number: 2, length: 6]\n  ]\n"
     end
   end
 
diff --git a/test/pleroma/chat/message_reference_test.exs b/test/pleroma/chat/message_reference_test.exs
new file mode 100644
index 000000000..c8db3b450
--- /dev/null
+++ b/test/pleroma/chat/message_reference_test.exs
@@ -0,0 +1,29 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Chat.MessageReferenceTest do
+  use Pleroma.DataCase, async: true
+
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.Web.CommonAPI
+
+  import Pleroma.Factory
+
+  describe "messages" do
+    test "it returns the last message in a chat" do
+      user = insert(:user)
+      recipient = insert(:user)
+
+      {:ok, _message_1} = CommonAPI.post_chat_message(user, recipient, "hey")
+      {:ok, _message_2} = CommonAPI.post_chat_message(recipient, user, "ho")
+
+      {:ok, chat} = Chat.get_or_create(user.id, recipient.ap_id)
+
+      message = MessageReference.last_message_for_chat(chat)
+
+      assert message.object.data["content"] == "ho"
+    end
+  end
+end
diff --git a/test/pleroma/chat_test.exs b/test/pleroma/chat_test.exs
new file mode 100644
index 000000000..a5fd1e02e
--- /dev/null
+++ b/test/pleroma/chat_test.exs
@@ -0,0 +1,84 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.ChatTest do
+  use Pleroma.DataCase, async: true
+
+  alias Pleroma.Chat
+
+  import Pleroma.Factory
+
+  describe "creation and getting" do
+    test "it only works if the recipient is a valid user (for now)" do
+      user = insert(:user)
+
+      assert {:error, _chat} = Chat.bump_or_create(user.id, "http://some/nonexisting/account")
+      assert {:error, _chat} = Chat.get_or_create(user.id, "http://some/nonexisting/account")
+    end
+
+    test "it creates a chat for a user and recipient" do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.bump_or_create(user.id, other_user.ap_id)
+
+      assert chat.id
+    end
+
+    test "deleting the user deletes the chat" do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.bump_or_create(user.id, other_user.ap_id)
+
+      Repo.delete(user)
+
+      refute Chat.get_by_id(chat.id)
+    end
+
+    test "deleting the recipient deletes the chat" do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.bump_or_create(user.id, other_user.ap_id)
+
+      Repo.delete(other_user)
+
+      refute Chat.get_by_id(chat.id)
+    end
+
+    test "it returns and bumps a chat for a user and recipient if it already exists" do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.bump_or_create(user.id, other_user.ap_id)
+      {:ok, chat_two} = Chat.bump_or_create(user.id, other_user.ap_id)
+
+      assert chat.id == chat_two.id
+    end
+
+    test "it returns a chat for a user and recipient if it already exists" do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+      {:ok, chat_two} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      assert chat.id == chat_two.id
+    end
+
+    test "a returning chat will have an updated `update_at` field" do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.bump_or_create(user.id, other_user.ap_id)
+      {:ok, chat} = time_travel(chat, -2)
+
+      {:ok, chat_two} = Chat.bump_or_create(user.id, other_user.ap_id)
+
+      assert chat.id == chat_two.id
+      assert chat.updated_at != chat_two.updated_at
+    end
+  end
+end
diff --git a/test/pleroma/config/deprecation_warnings_test.exs b/test/pleroma/config/deprecation_warnings_test.exs
index b18267a7f..a2712bb4e 100644
--- a/test/pleroma/config/deprecation_warnings_test.exs
+++ b/test/pleroma/config/deprecation_warnings_test.exs
@@ -289,4 +289,14 @@ defmodule Pleroma.Config.DeprecationWarningsTest do
 
     Application.put_env(:tesla, :adapter, Tesla.Mock)
   end
+  
+  test "check_old_chat_shoutbox/0" do
+    clear_config([:instance, :chat_limit], 1_000)
+    clear_config([:chat, :enabled], true)
+
+    assert capture_log(fn ->
+             DeprecationWarnings.check_old_chat_shoutbox()
+           end) =~
+             "Your config is using the old namespace for the Shoutbox configuration."
+  end
 end
diff --git a/test/pleroma/config/transfer_task_test.exs b/test/pleroma/config/transfer_task_test.exs
index 6491d10fb..d964803b9 100644
--- a/test/pleroma/config/transfer_task_test.exs
+++ b/test/pleroma/config/transfer_task_test.exs
@@ -140,6 +140,9 @@ defmodule Pleroma.Config.TransferTaskTest do
                # That way we are sure that the previous call has finished before we continue.
                Restarter.Pleroma.rebooted?()
              end) =~ "pleroma restarted"
+      clear_config(:shout)
+      insert(:config, key: :shout, value: [enabled: false])
+      assert capture_log(fn -> TransferTask.start_link([]) end) =~ "pleroma restarted"
     end
 
     test "on reboot time subkey" do
@@ -164,6 +167,10 @@ defmodule Pleroma.Config.TransferTaskTest do
       clear_config(Pleroma.Captcha)
 
       insert(:config, key: :rate_limit, value: [enabled: false])
+      clear_config(:shout)
+      clear_config(Pleroma.Captcha)
+
+      insert(:config, key: :shout, value: [enabled: false])
       insert(:config, key: Pleroma.Captcha, value: [seconds_valid: 60])
 
       refute String.contains?(
diff --git a/test/pleroma/migration_helper/notification_backfill_test.exs b/test/pleroma/migration_helper/notification_backfill_test.exs
index eca060800..fd253b530 100644
--- a/test/pleroma/migration_helper/notification_backfill_test.exs
+++ b/test/pleroma/migration_helper/notification_backfill_test.exs
@@ -19,6 +19,7 @@ defmodule Pleroma.MigrationHelper.NotificationBackfillTest do
       other_user = insert(:user)
 
       {:ok, post} = CommonAPI.post(user, %{status: "yeah, @#{other_user.nickname}"})
+      {:ok, chat} = CommonAPI.post_chat_message(user, other_user, "yo")
       {:ok, react} = CommonAPI.react_with_emoji(post.id, other_user, "☕")
       {:ok, like} = CommonAPI.favorite(other_user, post.id)
       {:ok, react_2} = CommonAPI.react_with_emoji(post.id, other_user, "☕")
@@ -32,7 +33,7 @@ defmodule Pleroma.MigrationHelper.NotificationBackfillTest do
         |> Activity.change(%{data: data})
         |> Repo.update()
 
-      assert {4, nil} = Repo.update_all(Notification, set: [type: nil])
+      assert {5, nil} = Repo.update_all(Notification, set: [type: nil])
 
       NotificationBackfill.fill_in_notification_types()
 
@@ -47,6 +48,9 @@ defmodule Pleroma.MigrationHelper.NotificationBackfillTest do
 
       assert %{type: "pleroma:emoji_reaction"} =
                Repo.get_by(Notification, user_id: user.id, activity_id: react_2.id)
+
+      assert %{type: "pleroma:chat_mention"} =
+               Repo.get_by(Notification, user_id: other_user.id, activity_id: chat.id)
     end
   end
 end
diff --git a/test/pleroma/repo/migrations/rename_instance_chat_test.exs b/test/pleroma/repo/migrations/rename_instance_chat_test.exs
new file mode 100644
index 000000000..acd45600c
--- /dev/null
+++ b/test/pleroma/repo/migrations/rename_instance_chat_test.exs
@@ -0,0 +1,52 @@
+defmodule Pleroma.Repo.Migrations.RenameInstanceChatTest do
+  use Pleroma.DataCase
+  import Pleroma.Factory
+  import Pleroma.Tests.Helpers
+  alias Pleroma.ConfigDB
+
+  setup do: clear_config([:instance])
+  setup do: clear_config([:chat])
+  setup_all do: require_migration("20200806175913_rename_instance_chat")
+
+  describe "up/0" do
+    test "migrates chat settings to shout", %{migration: migration} do
+      insert(:config, group: :pleroma, key: :instance, value: [chat_limit: 6000])
+      insert(:config, group: :pleroma, key: :chat, value: [enabled: true])
+
+      assert migration.up() == :ok
+
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :chat}) == nil
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :instance}) == nil
+
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :shout}).value == [
+               limit: 6000,
+               enabled: true
+             ]
+    end
+
+    test "does nothing when chat settings are not set", %{migration: migration} do
+      assert migration.up() == :noop
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :chat}) == nil
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :shout}) == nil
+    end
+  end
+
+  describe "down/0" do
+    test "migrates shout settings back to instance and chat", %{migration: migration} do
+      insert(:config, group: :pleroma, key: :shout, value: [limit: 42, enabled: true])
+
+      assert migration.down() == :ok
+
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :chat}).value == [enabled: true]
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :instance}).value == [chat_limit: 42]
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :shout}) == nil
+    end
+
+    test "does nothing when shout settings are not set", %{migration: migration} do
+      assert migration.down() == :noop
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :chat}) == nil
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :instance}) == nil
+      assert ConfigDB.get_by_params(%{group: :pleroma, key: :shout}) == nil
+    end
+  end
+end
diff --git a/test/pleroma/user/welcome_chat_message_test.exs b/test/pleroma/user/welcome_chat_message_test.exs
new file mode 100644
index 000000000..42a45fa19
--- /dev/null
+++ b/test/pleroma/user/welcome_chat_message_test.exs
@@ -0,0 +1,36 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.User.WelcomeChatMessageTest do
+  use Pleroma.DataCase
+
+  alias Pleroma.User.WelcomeChatMessage
+
+  import Pleroma.Factory
+
+  setup do: clear_config([:welcome])
+
+  describe "post_message/1" do
+    test "send a chat welcome message" do
+      welcome_user = insert(:user, name: "mewmew")
+      user = insert(:user)
+
+      clear_config([:welcome, :chat_message, :enabled], true)
+      clear_config([:welcome, :chat_message, :sender_nickname], welcome_user.nickname)
+
+      clear_config(
+        [:welcome, :chat_message, :message],
+        "Hello, welcome to Blob/Cat!"
+      )
+
+      {:ok, %Pleroma.Activity{} = activity} = WelcomeChatMessage.post_message(user)
+
+      assert user.ap_id in activity.recipients
+      assert Pleroma.Object.normalize(activity, fetch: false).data["type"] == "ChatMessage"
+
+      assert Pleroma.Object.normalize(activity, fetch: false).data["content"] ==
+               "Hello, welcome to Blob/Cat!"
+    end
+  end
+end
diff --git a/test/pleroma/user_test.exs b/test/pleroma/user_test.exs
index a590946c2..d13b90b51 100644
--- a/test/pleroma/user_test.exs
+++ b/test/pleroma/user_test.exs
@@ -443,6 +443,22 @@ defmodule Pleroma.UserTest do
       assert activity.actor == welcome_user.ap_id
     end
 
+    test "it sends a welcome chat message if it is set" do
+      welcome_user = insert(:user)
+      clear_config([:welcome, :chat_message, :enabled], true)
+      clear_config([:welcome, :chat_message, :sender_nickname], welcome_user.nickname)
+      clear_config([:welcome, :chat_message, :message], "Hello, this is a chat message")
+
+      cng = User.register_changeset(%User{}, @full_user_data)
+      {:ok, registered_user} = User.register(cng)
+      ObanHelpers.perform_all()
+
+      activity = Repo.one(Pleroma.Activity)
+      assert registered_user.ap_id in activity.recipients
+      assert Object.normalize(activity, fetch: false).data["content"] =~ "chat message"
+      assert activity.actor == welcome_user.ap_id
+    end
+
     setup do:
             clear_config(
               [:mrf_simple],
@@ -467,6 +483,24 @@ defmodule Pleroma.UserTest do
               ]
             )
 
+    test "it sends a welcome chat message when Simple policy applied to local instance" do
+      clear_config([:mrf_simple, :media_nsfw], [{"localhost", ""}])
+
+      welcome_user = insert(:user)
+      clear_config([:welcome, :chat_message, :enabled], true)
+      clear_config([:welcome, :chat_message, :sender_nickname], welcome_user.nickname)
+      clear_config([:welcome, :chat_message, :message], "Hello, this is a chat message")
+
+      cng = User.register_changeset(%User{}, @full_user_data)
+      {:ok, registered_user} = User.register(cng)
+      ObanHelpers.perform_all()
+
+      activity = Repo.one(Pleroma.Activity)
+      assert registered_user.ap_id in activity.recipients
+      assert Object.normalize(activity, fetch: false).data["content"] =~ "chat message"
+      assert activity.actor == welcome_user.ap_id
+    end
+
     test "it sends a welcome email message if it is set" do
       welcome_user = insert(:user)
       clear_config([:welcome, :email, :enabled], true)
@@ -632,6 +666,15 @@ defmodule Pleroma.UserTest do
       assert changeset.changes.follower_address == "#{changeset.changes.ap_id}/followers"
     end
 
+    test "it sets the 'accepts_chat_messages' set to true" do
+      changeset = User.register_changeset(%User{}, @full_user_data)
+      assert changeset.valid?
+
+      {:ok, user} = Repo.insert(changeset)
+
+      assert user.accepts_chat_messages
+    end
+
     test "it creates a confirmed user" do
       changeset = User.register_changeset(%User{}, @full_user_data)
       assert changeset.valid?
diff --git a/test/pleroma/web/activity_pub/activity_pub_test.exs b/test/pleroma/web/activity_pub/activity_pub_test.exs
index 17c52fc91..676465ff9 100644
--- a/test/pleroma/web/activity_pub/activity_pub_test.exs
+++ b/test/pleroma/web/activity_pub/activity_pub_test.exs
@@ -187,6 +187,13 @@ defmodule Pleroma.Web.ActivityPub.ActivityPubTest do
       assert User.invisible?(user)
     end
 
+    test "it returns a user that accepts chat messages" do
+      user_id = "http://mastodon.example.org/users/admin"
+      {:ok, user} = ActivityPub.make_user_from_ap_id(user_id)
+
+      assert user.accepts_chat_messages
+    end
+
     test "works for guppe actors" do
       user_id = "https://gup.pe/u/bernie2020"
 
diff --git a/test/pleroma/web/activity_pub/mrf/hellthread_policy_test.exs b/test/pleroma/web/activity_pub/mrf/hellthread_policy_test.exs
index 2bcf49bc5..3a469a619 100644
--- a/test/pleroma/web/activity_pub/mrf/hellthread_policy_test.exs
+++ b/test/pleroma/web/activity_pub/mrf/hellthread_policy_test.exs
@@ -8,6 +8,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.HellthreadPolicyTest do
 
   import Pleroma.Web.ActivityPub.MRF.HellthreadPolicy
 
+  alias Pleroma.Web.CommonAPI
+
   setup do
     user = insert(:user)
 
@@ -46,6 +48,17 @@ defmodule Pleroma.Web.ActivityPub.MRF.HellthreadPolicyTest do
 
   setup do: clear_config(:mrf_hellthread)
 
+  test "doesn't die on chat messages" do
+    clear_config([:mrf_hellthread], %{delist_threshold: 2, reject_threshold: 0})
+
+    user = insert(:user)
+    other_user = insert(:user)
+
+    {:ok, activity} = CommonAPI.post_chat_message(user, other_user, "moin")
+
+    assert {:ok, _} = filter(activity.data)
+  end
+
   describe "reject" do
     test "rejects the message if the recipient count is above reject_threshold", %{
       message: message,
diff --git a/test/pleroma/web/activity_pub/object_validators/chat_validation_test.exs b/test/pleroma/web/activity_pub/object_validators/chat_validation_test.exs
new file mode 100644
index 000000000..def2a10b4
--- /dev/null
+++ b/test/pleroma/web/activity_pub/object_validators/chat_validation_test.exs
@@ -0,0 +1,212 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.ChatValidationTest do
+  use Pleroma.DataCase
+  alias Pleroma.Object
+  alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.ActivityPub.Builder
+  alias Pleroma.Web.ActivityPub.ObjectValidator
+  alias Pleroma.Web.CommonAPI
+
+  import Pleroma.Factory
+
+  describe "chat message create activities" do
+    test "it is invalid if the object already exists" do
+      user = insert(:user)
+      recipient = insert(:user)
+      {:ok, activity} = CommonAPI.post_chat_message(user, recipient, "hey")
+      object = Object.normalize(activity, fetch: false)
+
+      {:ok, create_data, _} = Builder.create(user, object.data, [recipient.ap_id])
+
+      {:error, cng} = ObjectValidator.validate(create_data, [])
+
+      assert {:object, {"The object to create already exists", []}} in cng.errors
+    end
+
+    test "it is invalid if the object data has a different `to` or `actor` field" do
+      user = insert(:user)
+      recipient = insert(:user)
+      {:ok, object_data, _} = Builder.chat_message(recipient, user.ap_id, "Hey")
+
+      {:ok, create_data, _} = Builder.create(user, object_data, [recipient.ap_id])
+
+      {:error, cng} = ObjectValidator.validate(create_data, [])
+
+      assert {:to, {"Recipients don't match with object recipients", []}} in cng.errors
+      assert {:actor, {"Actor doesn't match with object actor", []}} in cng.errors
+    end
+  end
+
+  describe "chat messages" do
+    setup do
+      clear_config([:instance, :remote_limit])
+      user = insert(:user)
+      recipient = insert(:user, local: false)
+
+      {:ok, valid_chat_message, _} = Builder.chat_message(user, recipient.ap_id, "hey :firefox:")
+
+      %{user: user, recipient: recipient, valid_chat_message: valid_chat_message}
+    end
+
+    test "let's through some basic html", %{user: user, recipient: recipient} do
+      {:ok, valid_chat_message, _} =
+        Builder.chat_message(
+          user,
+          recipient.ap_id,
+          "hey <a href='https://example.org'>example</a> <script>alert('uguu')</script>"
+        )
+
+      assert {:ok, object, _meta} = ObjectValidator.validate(valid_chat_message, [])
+
+      assert object["content"] ==
+               "hey <a href=\"https://example.org\">example</a> alert(&#39;uguu&#39;)"
+    end
+
+    test "validates for a basic object we build", %{valid_chat_message: valid_chat_message} do
+      assert {:ok, object, _meta} = ObjectValidator.validate(valid_chat_message, [])
+
+      assert valid_chat_message == object
+      assert match?(%{"firefox" => _}, object["emoji"])
+    end
+
+    test "validates for a basic object with an attachment", %{
+      valid_chat_message: valid_chat_message,
+      user: user
+    } do
+      file = %Plug.Upload{
+        content_type: "image/jpeg",
+        path: Path.absname("test/fixtures/image.jpg"),
+        filename: "an_image.jpg"
+      }
+
+      {:ok, attachment} = ActivityPub.upload(file, actor: user.ap_id)
+
+      valid_chat_message =
+        valid_chat_message
+        |> Map.put("attachment", attachment.data)
+
+      assert {:ok, object, _meta} = ObjectValidator.validate(valid_chat_message, [])
+
+      assert object["attachment"]
+    end
+
+    test "validates for a basic object with an attachment in an array", %{
+      valid_chat_message: valid_chat_message,
+      user: user
+    } do
+      file = %Plug.Upload{
+        content_type: "image/jpeg",
+        path: Path.absname("test/fixtures/image.jpg"),
+        filename: "an_image.jpg"
+      }
+
+      {:ok, attachment} = ActivityPub.upload(file, actor: user.ap_id)
+
+      valid_chat_message =
+        valid_chat_message
+        |> Map.put("attachment", [attachment.data])
+
+      assert {:ok, object, _meta} = ObjectValidator.validate(valid_chat_message, [])
+
+      assert object["attachment"]
+    end
+
+    test "validates for a basic object with an attachment but without content", %{
+      valid_chat_message: valid_chat_message,
+      user: user
+    } do
+      file = %Plug.Upload{
+        content_type: "image/jpeg",
+        path: Path.absname("test/fixtures/image.jpg"),
+        filename: "an_image.jpg"
+      }
+
+      {:ok, attachment} = ActivityPub.upload(file, actor: user.ap_id)
+
+      valid_chat_message =
+        valid_chat_message
+        |> Map.put("attachment", attachment.data)
+        |> Map.delete("content")
+
+      assert {:ok, object, _meta} = ObjectValidator.validate(valid_chat_message, [])
+
+      assert object["attachment"]
+    end
+
+    test "does not validate if the message has no content", %{
+      valid_chat_message: valid_chat_message
+    } do
+      contentless =
+        valid_chat_message
+        |> Map.delete("content")
+
+      refute match?({:ok, _object, _meta}, ObjectValidator.validate(contentless, []))
+    end
+
+    test "does not validate if the message is longer than the remote_limit", %{
+      valid_chat_message: valid_chat_message
+    } do
+      clear_config([:instance, :remote_limit], 2)
+      refute match?({:ok, _object, _meta}, ObjectValidator.validate(valid_chat_message, []))
+    end
+
+    test "does not validate if the recipient is blocking the actor", %{
+      valid_chat_message: valid_chat_message,
+      user: user,
+      recipient: recipient
+    } do
+      Pleroma.User.block(recipient, user)
+      refute match?({:ok, _object, _meta}, ObjectValidator.validate(valid_chat_message, []))
+    end
+
+    test "does not validate if the recipient is not accepting chat messages", %{
+      valid_chat_message: valid_chat_message,
+      recipient: recipient
+    } do
+      recipient
+      |> Ecto.Changeset.change(%{accepts_chat_messages: false})
+      |> Pleroma.Repo.update!()
+
+      refute match?({:ok, _object, _meta}, ObjectValidator.validate(valid_chat_message, []))
+    end
+
+    test "does not validate if the actor or the recipient is not in our system", %{
+      valid_chat_message: valid_chat_message
+    } do
+      chat_message =
+        valid_chat_message
+        |> Map.put("actor", "https://raymoo.com/raymoo")
+
+      {:error, _} = ObjectValidator.validate(chat_message, [])
+
+      chat_message =
+        valid_chat_message
+        |> Map.put("to", ["https://raymoo.com/raymoo"])
+
+      {:error, _} = ObjectValidator.validate(chat_message, [])
+    end
+
+    test "does not validate for a message with multiple recipients", %{
+      valid_chat_message: valid_chat_message,
+      user: user,
+      recipient: recipient
+    } do
+      chat_message =
+        valid_chat_message
+        |> Map.put("to", [user.ap_id, recipient.ap_id])
+
+      assert {:error, _} = ObjectValidator.validate(chat_message, [])
+    end
+
+    test "does not validate if it doesn't concern local users" do
+      user = insert(:user, local: false)
+      recipient = insert(:user, local: false)
+
+      {:ok, valid_chat_message, _} = Builder.chat_message(user, recipient.ap_id, "hey")
+      assert {:error, _} = ObjectValidator.validate(valid_chat_message, [])
+    end
+  end
+end
diff --git a/test/pleroma/web/activity_pub/side_effects_test.exs b/test/pleroma/web/activity_pub/side_effects_test.exs
index ee664bb8f..890814c5d 100644
--- a/test/pleroma/web/activity_pub/side_effects_test.exs
+++ b/test/pleroma/web/activity_pub/side_effects_test.exs
@@ -7,6 +7,8 @@ defmodule Pleroma.Web.ActivityPub.SideEffectsTest do
   use Pleroma.DataCase
 
   alias Pleroma.Activity
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
   alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.Repo
@@ -15,7 +17,6 @@ defmodule Pleroma.Web.ActivityPub.SideEffectsTest do
   alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Builder
   alias Pleroma.Web.ActivityPub.SideEffects
-  alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.CommonAPI
 
   import Mock
@@ -55,22 +56,15 @@ defmodule Pleroma.Web.ActivityPub.SideEffectsTest do
       author = insert(:user, local: true)
       recipient = insert(:user, local: true)
 
-      {:ok, note_data, _meta} =
-        Builder.note(%Pleroma.Web.CommonAPI.ActivityDraft{
-          user: author,
-          to: [recipient.ap_id],
-          mentions: [recipient],
-          content_html: "hey",
-          extra: %{"id" => Utils.generate_object_id()}
-        })
+      {:ok, chat_message_data, _meta} = Builder.chat_message(author, recipient.ap_id, "hey")
 
       {:ok, create_activity_data, _meta} =
-        Builder.create(author, note_data["id"], [recipient.ap_id])
+        Builder.create(author, chat_message_data["id"], [recipient.ap_id])
 
       {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
 
       {:ok, _create_activity, meta} =
-        SideEffects.handle(create_activity, local: false, object_data: note_data)
+        SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
 
       assert [notification] = meta[:notifications]
 
@@ -93,6 +87,7 @@ defmodule Pleroma.Web.ActivityPub.SideEffectsTest do
         SideEffects.handle_after_transaction(meta)
 
         assert called(Pleroma.Web.Streamer.stream(["user", "user:notification"], notification))
+        assert called(Pleroma.Web.Streamer.stream(["user", "user:pleroma_chat"], :_))
         assert called(Pleroma.Web.Push.send(notification))
       end
     end
@@ -665,6 +660,147 @@ defmodule Pleroma.Web.ActivityPub.SideEffectsTest do
     end
   end
 
+  describe "creation of ChatMessages" do
+    test "notifies the recipient" do
+      author = insert(:user, local: false)
+      recipient = insert(:user, local: true)
+
+      {:ok, chat_message_data, _meta} = Builder.chat_message(author, recipient.ap_id, "hey")
+
+      {:ok, create_activity_data, _meta} =
+        Builder.create(author, chat_message_data["id"], [recipient.ap_id])
+
+      {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
+
+      {:ok, _create_activity, _meta} =
+        SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
+
+      assert Repo.get_by(Notification, user_id: recipient.id, activity_id: create_activity.id)
+    end
+
+    test "it streams the created ChatMessage" do
+      author = insert(:user, local: true)
+      recipient = insert(:user, local: true)
+
+      {:ok, chat_message_data, _meta} = Builder.chat_message(author, recipient.ap_id, "hey")
+
+      {:ok, create_activity_data, _meta} =
+        Builder.create(author, chat_message_data["id"], [recipient.ap_id])
+
+      {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
+
+      {:ok, _create_activity, meta} =
+        SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
+
+      assert [_, _] = meta[:streamables]
+    end
+
+    test "it creates a Chat and MessageReferences for the local users and bumps the unread count, except for the author" do
+      author = insert(:user, local: true)
+      recipient = insert(:user, local: true)
+
+      {:ok, chat_message_data, _meta} = Builder.chat_message(author, recipient.ap_id, "hey")
+
+      {:ok, create_activity_data, _meta} =
+        Builder.create(author, chat_message_data["id"], [recipient.ap_id])
+
+      {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
+
+      with_mocks([
+        {
+          Pleroma.Web.Streamer,
+          [],
+          [
+            stream: fn _, _ -> nil end
+          ]
+        },
+        {
+          Pleroma.Web.Push,
+          [],
+          [
+            send: fn _ -> nil end
+          ]
+        }
+      ]) do
+        {:ok, _create_activity, meta} =
+          SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
+
+        # The notification gets created
+        assert [notification] = meta[:notifications]
+        assert notification.activity_id == create_activity.id
+
+        # But it is not sent out
+        refute called(Pleroma.Web.Streamer.stream(["user", "user:notification"], notification))
+        refute called(Pleroma.Web.Push.send(notification))
+
+        # Same for the user chat stream
+        assert [{topics, _}, _] = meta[:streamables]
+        assert topics == ["user", "user:pleroma_chat"]
+        refute called(Pleroma.Web.Streamer.stream(["user", "user:pleroma_chat"], :_))
+
+        chat = Chat.get(author.id, recipient.ap_id)
+
+        [cm_ref] = MessageReference.for_chat_query(chat) |> Repo.all()
+
+        assert cm_ref.object.data["content"] == "hey"
+        assert cm_ref.unread == false
+
+        chat = Chat.get(recipient.id, author.ap_id)
+
+        [cm_ref] = MessageReference.for_chat_query(chat) |> Repo.all()
+
+        assert cm_ref.object.data["content"] == "hey"
+        assert cm_ref.unread == true
+      end
+    end
+
+    test "it creates a Chat for the local users and bumps the unread count" do
+      author = insert(:user, local: false)
+      recipient = insert(:user, local: true)
+
+      {:ok, chat_message_data, _meta} = Builder.chat_message(author, recipient.ap_id, "hey")
+
+      {:ok, create_activity_data, _meta} =
+        Builder.create(author, chat_message_data["id"], [recipient.ap_id])
+
+      {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
+
+      {:ok, _create_activity, _meta} =
+        SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
+
+      # An object is created
+      assert Object.get_by_ap_id(chat_message_data["id"])
+
+      # The remote user won't get a chat
+      chat = Chat.get(author.id, recipient.ap_id)
+      refute chat
+
+      # The local user will get a chat
+      chat = Chat.get(recipient.id, author.ap_id)
+      assert chat
+
+      author = insert(:user, local: true)
+      recipient = insert(:user, local: true)
+
+      {:ok, chat_message_data, _meta} = Builder.chat_message(author, recipient.ap_id, "hey")
+
+      {:ok, create_activity_data, _meta} =
+        Builder.create(author, chat_message_data["id"], [recipient.ap_id])
+
+      {:ok, create_activity, _meta} = ActivityPub.persist(create_activity_data, local: false)
+
+      {:ok, _create_activity, _meta} =
+        SideEffects.handle(create_activity, local: false, object_data: chat_message_data)
+
+      # Both users are local and get the chat
+      chat = Chat.get(author.id, recipient.ap_id)
+      assert chat
+
+      chat = Chat.get(recipient.id, author.ap_id)
+      assert chat
+    end
+  end
+
   describe "announce objects" do
     setup do
       poster = insert(:user)
diff --git a/test/pleroma/web/activity_pub/transmogrifier/chat_message_test.exs b/test/pleroma/web/activity_pub/transmogrifier/chat_message_test.exs
new file mode 100644
index 000000000..958675835
--- /dev/null
+++ b/test/pleroma/web/activity_pub/transmogrifier/chat_message_test.exs
@@ -0,0 +1,171 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.Transmogrifier.ChatMessageTest do
+  use Pleroma.DataCase
+
+  import Pleroma.Factory
+
+  alias Pleroma.Activity
+  alias Pleroma.Chat
+  alias Pleroma.Object
+  alias Pleroma.Web.ActivityPub.Transmogrifier
+
+  describe "handle_incoming" do
+    test "handles chonks with attachment" do
+      data = %{
+        "@context" => "https://www.w3.org/ns/activitystreams",
+        "actor" => "https://honk.tedunangst.com/u/tedu",
+        "id" => "https://honk.tedunangst.com/u/tedu/honk/x6gt8X8PcyGkQcXxzg1T",
+        "object" => %{
+          "attachment" => [
+            %{
+              "mediaType" => "image/jpeg",
+              "name" => "298p3RG7j27tfsZ9RQ.jpg",
+              "summary" => "298p3RG7j27tfsZ9RQ.jpg",
+              "type" => "Document",
+              "url" => "https://honk.tedunangst.com/d/298p3RG7j27tfsZ9RQ.jpg"
+            }
+          ],
+          "attributedTo" => "https://honk.tedunangst.com/u/tedu",
+          "content" => "",
+          "id" => "https://honk.tedunangst.com/u/tedu/chonk/26L4wl5yCbn4dr4y1b",
+          "published" => "2020-05-18T01:13:03Z",
+          "to" => [
+            "https://dontbulling.me/users/lain"
+          ],
+          "type" => "ChatMessage"
+        },
+        "published" => "2020-05-18T01:13:03Z",
+        "to" => [
+          "https://dontbulling.me/users/lain"
+        ],
+        "type" => "Create"
+      }
+
+      _user = insert(:user, ap_id: data["actor"])
+      _user = insert(:user, ap_id: hd(data["to"]))
+
+      assert {:ok, _activity} = Transmogrifier.handle_incoming(data)
+    end
+
+    test "it rejects messages that don't contain content" do
+      data =
+        File.read!("test/fixtures/create-chat-message.json")
+        |> Jason.decode!()
+
+      object =
+        data["object"]
+        |> Map.delete("content")
+
+      data =
+        data
+        |> Map.put("object", object)
+
+      _author =
+        insert(:user, ap_id: data["actor"], local: false, last_refreshed_at: DateTime.utc_now())
+
+      _recipient =
+        insert(:user,
+          ap_id: List.first(data["to"]),
+          local: true,
+          last_refreshed_at: DateTime.utc_now()
+        )
+
+      {:error, _} = Transmogrifier.handle_incoming(data)
+    end
+
+    test "it rejects messages that don't concern local users" do
+      data =
+        File.read!("test/fixtures/create-chat-message.json")
+        |> Jason.decode!()
+
+      _author =
+        insert(:user, ap_id: data["actor"], local: false, last_refreshed_at: DateTime.utc_now())
+
+      _recipient =
+        insert(:user,
+          ap_id: List.first(data["to"]),
+          local: false,
+          last_refreshed_at: DateTime.utc_now()
+        )
+
+      {:error, _} = Transmogrifier.handle_incoming(data)
+    end
+
+    test "it rejects messages where the `to` field of activity and object don't match" do
+      data =
+        File.read!("test/fixtures/create-chat-message.json")
+        |> Jason.decode!()
+
+      author = insert(:user, ap_id: data["actor"])
+      _recipient = insert(:user, ap_id: List.first(data["to"]))
+
+      data =
+        data
+        |> Map.put("to", author.ap_id)
+
+      assert match?({:error, _}, Transmogrifier.handle_incoming(data))
+      refute Object.get_by_ap_id(data["object"]["id"])
+    end
+
+    test "it fetches the actor if they aren't in our system" do
+      Tesla.Mock.mock(fn env -> apply(HttpRequestMock, :request, [env]) end)
+
+      data =
+        File.read!("test/fixtures/create-chat-message.json")
+        |> Jason.decode!()
+        |> Map.put("actor", "http://mastodon.example.org/users/admin")
+        |> put_in(["object", "actor"], "http://mastodon.example.org/users/admin")
+
+      _recipient = insert(:user, ap_id: List.first(data["to"]), local: true)
+
+      {:ok, %Activity{} = _activity} = Transmogrifier.handle_incoming(data)
+    end
+
+    test "it doesn't work for deactivated users" do
+      data =
+        File.read!("test/fixtures/create-chat-message.json")
+        |> Jason.decode!()
+
+      _author =
+        insert(:user,
+          ap_id: data["actor"],
+          local: false,
+          last_refreshed_at: DateTime.utc_now(),
+          is_active: false
+        )
+
+      _recipient = insert(:user, ap_id: List.first(data["to"]), local: true)
+
+      assert {:error, _} = Transmogrifier.handle_incoming(data)
+    end
+
+    test "it inserts it and creates a chat" do
+      data =
+        File.read!("test/fixtures/create-chat-message.json")
+        |> Jason.decode!()
+
+      author =
+        insert(:user, ap_id: data["actor"], local: false, last_refreshed_at: DateTime.utc_now())
+
+      recipient = insert(:user, ap_id: List.first(data["to"]), local: true)
+
+      {:ok, %Activity{} = activity} = Transmogrifier.handle_incoming(data)
+      assert activity.local == false
+
+      assert activity.actor == author.ap_id
+      assert activity.recipients == [recipient.ap_id, author.ap_id]
+
+      %Object{} = object = Object.get_by_ap_id(activity.data["object"])
+
+      assert object
+      assert object.data["content"] == "You expected a cute girl? Too bad. alert(&#39;XSS&#39;)"
+      assert match?(%{"firefox" => _}, object.data["emoji"])
+
+      refute Chat.get(author.id, recipient.ap_id)
+      assert Chat.get(recipient.id, author.ap_id)
+    end
+  end
+end
diff --git a/test/pleroma/web/activity_pub/views/user_view_test.exs b/test/pleroma/web/activity_pub/views/user_view_test.exs
index 5501e64d6..879c8e04b 100644
--- a/test/pleroma/web/activity_pub/views/user_view_test.exs
+++ b/test/pleroma/web/activity_pub/views/user_view_test.exs
@@ -157,4 +157,23 @@ defmodule Pleroma.Web.ActivityPub.UserViewTest do
       assert %{"totalItems" => 1} = UserView.render("following.json", %{user: user})
     end
   end
+
+  describe "acceptsChatMessages" do
+    test "it returns this value if it is set" do
+      true_user = insert(:user, accepts_chat_messages: true)
+      false_user = insert(:user, accepts_chat_messages: false)
+      nil_user = insert(:user, accepts_chat_messages: nil)
+
+      assert %{"capabilities" => %{"acceptsChatMessages" => true}} =
+               UserView.render("user.json", user: true_user)
+
+      assert %{"capabilities" => %{"acceptsChatMessages" => false}} =
+               UserView.render("user.json", user: false_user)
+
+      refute Map.has_key?(
+               UserView.render("user.json", user: nil_user)["capabilities"],
+               "acceptsChatMessages"
+             )
+    end
+  end
 end
diff --git a/test/pleroma/web/admin_api/controllers/admin_api_controller_test.exs b/test/pleroma/web/admin_api/controllers/admin_api_controller_test.exs
index e423b2311..ada01709d 100644
--- a/test/pleroma/web/admin_api/controllers/admin_api_controller_test.exs
+++ b/test/pleroma/web/admin_api/controllers/admin_api_controller_test.exs
@@ -420,6 +420,56 @@ defmodule Pleroma.Web.AdminAPI.AdminAPIControllerTest do
     end
   end
 
+  describe "GET /api/pleroma/admin/users/:nickname/chats" do
+    setup do
+      user = insert(:user)
+      recipients = insert_list(3, :user)
+
+      Enum.each(recipients, fn recipient ->
+        CommonAPI.post_chat_message(user, recipient, "yo")
+      end)
+
+      %{user: user}
+    end
+
+    test "renders user's chats", %{conn: conn, user: user} do
+      conn = get(conn, "/api/pleroma/admin/users/#{user.nickname}/chats")
+
+      assert json_response(conn, 200) |> length() == 3
+    end
+  end
+
+  describe "GET /api/pleroma/admin/users/:nickname/chats unauthorized" do
+    setup do
+      user = insert(:user)
+      recipient = insert(:user)
+      CommonAPI.post_chat_message(user, recipient, "yo")
+      %{conn: conn} = oauth_access(["read:chats"])
+      %{conn: conn, user: user}
+    end
+
+    test "returns 403", %{conn: conn, user: user} do
+      conn
+      |> get("/api/pleroma/admin/users/#{user.nickname}/chats")
+      |> json_response(403)
+    end
+  end
+
+  describe "GET /api/pleroma/admin/users/:nickname/chats unauthenticated" do
+    setup do
+      user = insert(:user)
+      recipient = insert(:user)
+      CommonAPI.post_chat_message(user, recipient, "yo")
+      %{conn: build_conn(), user: user}
+    end
+
+    test "returns 403", %{conn: conn, user: user} do
+      conn
+      |> get("/api/pleroma/admin/users/#{user.nickname}/chats")
+      |> json_response(403)
+    end
+  end
+
   describe "GET /api/v1/pleroma/admin/moderation_log" do
     setup do
       moderator = insert(:user, is_moderator: true)
diff --git a/test/pleroma/web/admin_api/controllers/chat_controller_test.exs b/test/pleroma/web/admin_api/controllers/chat_controller_test.exs
new file mode 100644
index 000000000..0e8f7beef
--- /dev/null
+++ b/test/pleroma/web/admin_api/controllers/chat_controller_test.exs
@@ -0,0 +1,218 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.AdminAPI.ChatControllerTest do
+  use Pleroma.Web.ConnCase, async: true
+
+  import Pleroma.Factory
+
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.ModerationLog
+  alias Pleroma.Object
+  alias Pleroma.Repo
+  alias Pleroma.Web.CommonAPI
+
+  defp admin_setup do
+    admin = insert(:user, is_admin: true)
+    token = insert(:oauth_admin_token, user: admin)
+
+    conn =
+      build_conn()
+      |> assign(:user, admin)
+      |> assign(:token, token)
+
+    {:ok, %{admin: admin, token: token, conn: conn}}
+  end
+
+  describe "DELETE /api/pleroma/admin/chats/:id/messages/:message_id" do
+    setup do: admin_setup()
+
+    test "it deletes a message from the chat", %{conn: conn, admin: admin} do
+      user = insert(:user)
+      recipient = insert(:user)
+
+      {:ok, message} =
+        CommonAPI.post_chat_message(user, recipient, "Hello darkness my old friend")
+
+      object = Object.normalize(message, fetch: false)
+
+      chat = Chat.get(user.id, recipient.ap_id)
+      recipient_chat = Chat.get(recipient.id, user.ap_id)
+
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+      recipient_cm_ref = MessageReference.for_chat_and_object(recipient_chat, object)
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> delete("/api/pleroma/admin/chats/#{chat.id}/messages/#{cm_ref.id}")
+        |> json_response_and_validate_schema(200)
+
+      log_entry = Repo.one(ModerationLog)
+
+      assert ModerationLog.get_log_entry_message(log_entry) ==
+               "@#{admin.nickname} deleted chat message ##{cm_ref.id}"
+
+      assert result["id"] == cm_ref.id
+      refute MessageReference.get_by_id(cm_ref.id)
+      refute MessageReference.get_by_id(recipient_cm_ref.id)
+      assert %{data: %{"type" => "Tombstone"}} = Object.get_by_id(object.id)
+    end
+  end
+
+  describe "GET /api/pleroma/admin/chats/:id/messages" do
+    setup do: admin_setup()
+
+    test "it paginates", %{conn: conn} do
+      user = insert(:user)
+      recipient = insert(:user)
+
+      Enum.each(1..30, fn _ ->
+        {:ok, _} = CommonAPI.post_chat_message(user, recipient, "hey")
+      end)
+
+      chat = Chat.get(user.id, recipient.ap_id)
+
+      result =
+        conn
+        |> get("/api/pleroma/admin/chats/#{chat.id}/messages")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 20
+
+      result =
+        conn
+        |> get("/api/pleroma/admin/chats/#{chat.id}/messages?max_id=#{List.last(result)["id"]}")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 10
+    end
+
+    test "it returns the messages for a given chat", %{conn: conn} do
+      user = insert(:user)
+      other_user = insert(:user)
+      third_user = insert(:user)
+
+      {:ok, _} = CommonAPI.post_chat_message(user, other_user, "hey")
+      {:ok, _} = CommonAPI.post_chat_message(user, third_user, "hey")
+      {:ok, _} = CommonAPI.post_chat_message(user, other_user, "how are you?")
+      {:ok, _} = CommonAPI.post_chat_message(other_user, user, "fine, how about you?")
+
+      chat = Chat.get(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> get("/api/pleroma/admin/chats/#{chat.id}/messages")
+        |> json_response_and_validate_schema(200)
+
+      result
+      |> Enum.each(fn message ->
+        assert message["chat_id"] == chat.id |> to_string()
+      end)
+
+      assert length(result) == 3
+    end
+  end
+
+  describe "GET /api/pleroma/admin/chats/:id" do
+    setup do: admin_setup()
+
+    test "it returns a chat", %{conn: conn} do
+      user = insert(:user)
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> get("/api/pleroma/admin/chats/#{chat.id}")
+        |> json_response_and_validate_schema(200)
+
+      assert result["id"] == to_string(chat.id)
+      assert %{} = result["sender"]
+      assert %{} = result["receiver"]
+      refute result["account"]
+    end
+  end
+
+  describe "unauthorized chat moderation" do
+    setup do
+      user = insert(:user)
+      recipient = insert(:user)
+
+      {:ok, message} = CommonAPI.post_chat_message(user, recipient, "Yo")
+      object = Object.normalize(message, fetch: false)
+      chat = Chat.get(user.id, recipient.ap_id)
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      %{conn: conn} = oauth_access(["read:chats", "write:chats"])
+      %{conn: conn, chat: chat, cm_ref: cm_ref}
+    end
+
+    test "DELETE /api/pleroma/admin/chats/:id/messages/:message_id", %{
+      conn: conn,
+      chat: chat,
+      cm_ref: cm_ref
+    } do
+      conn
+      |> put_req_header("content-type", "application/json")
+      |> delete("/api/pleroma/admin/chats/#{chat.id}/messages/#{cm_ref.id}")
+      |> json_response(403)
+
+      assert MessageReference.get_by_id(cm_ref.id) == cm_ref
+    end
+
+    test "GET /api/pleroma/admin/chats/:id/messages", %{conn: conn, chat: chat} do
+      conn
+      |> get("/api/pleroma/admin/chats/#{chat.id}/messages")
+      |> json_response(403)
+    end
+
+    test "GET /api/pleroma/admin/chats/:id", %{conn: conn, chat: chat} do
+      conn
+      |> get("/api/pleroma/admin/chats/#{chat.id}")
+      |> json_response(403)
+    end
+  end
+
+  describe "unauthenticated chat moderation" do
+    setup do
+      user = insert(:user)
+      recipient = insert(:user)
+
+      {:ok, message} = CommonAPI.post_chat_message(user, recipient, "Yo")
+      object = Object.normalize(message, fetch: false)
+      chat = Chat.get(user.id, recipient.ap_id)
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      %{conn: build_conn(), chat: chat, cm_ref: cm_ref}
+    end
+
+    test "DELETE /api/pleroma/admin/chats/:id/messages/:message_id", %{
+      conn: conn,
+      chat: chat,
+      cm_ref: cm_ref
+    } do
+      conn
+      |> put_req_header("content-type", "application/json")
+      |> delete("/api/pleroma/admin/chats/#{chat.id}/messages/#{cm_ref.id}")
+      |> json_response(403)
+
+      assert MessageReference.get_by_id(cm_ref.id) == cm_ref
+    end
+
+    test "GET /api/pleroma/admin/chats/:id/messages", %{conn: conn, chat: chat} do
+      conn
+      |> get("/api/pleroma/admin/chats/#{chat.id}/messages")
+      |> json_response(403)
+    end
+
+    test "GET /api/pleroma/admin/chats/:id", %{conn: conn, chat: chat} do
+      conn
+      |> get("/api/pleroma/admin/chats/#{chat.id}")
+      |> json_response(403)
+    end
+  end
+end
diff --git a/test/pleroma/web/admin_api/controllers/config_controller_test.exs b/test/pleroma/web/admin_api/controllers/config_controller_test.exs
new file mode 100644
index 000000000..9c9e8513c
--- /dev/null
+++ b/test/pleroma/web/admin_api/controllers/config_controller_test.exs
@@ -0,0 +1,1525 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.AdminAPI.ConfigControllerTest do
+  use Pleroma.Web.ConnCase
+
+  import ExUnit.CaptureLog
+  import Pleroma.Factory
+
+  alias Pleroma.ConfigDB
+
+  setup do
+    admin = insert(:user, is_admin: true)
+    token = insert(:oauth_admin_token, user: admin)
+
+    conn =
+      build_conn()
+      |> assign(:user, admin)
+      |> assign(:token, token)
+
+    {:ok, %{admin: admin, token: token, conn: conn}}
+  end
+
+  describe "GET /api/pleroma/admin/config" do
+    setup do: clear_config(:configurable_from_database, true)
+
+    test "when configuration from database is off", %{conn: conn} do
+      clear_config(:configurable_from_database, false)
+      conn = get(conn, "/api/pleroma/admin/config")
+
+      assert json_response_and_validate_schema(conn, 400) ==
+               %{
+                 "error" => "You must enable configurable_from_database in your config file."
+               }
+    end
+
+    test "with settings only in db", %{conn: conn} do
+      config1 = insert(:config)
+      config2 = insert(:config)
+
+      conn = get(conn, "/api/pleroma/admin/config?only_db=true")
+
+      %{
+        "configs" => [
+          %{
+            "group" => ":pleroma",
+            "key" => key1,
+            "value" => _
+          },
+          %{
+            "group" => ":pleroma",
+            "key" => key2,
+            "value" => _
+          }
+        ]
+      } = json_response_and_validate_schema(conn, 200)
+
+      assert key1 == inspect(config1.key)
+      assert key2 == inspect(config2.key)
+    end
+
+    test "db is added to settings that are in db", %{conn: conn} do
+      _config = insert(:config, key: ":instance", value: [name: "Some name"])
+
+      %{"configs" => configs} =
+        conn
+        |> get("/api/pleroma/admin/config")
+        |> json_response_and_validate_schema(200)
+
+      [instance_config] =
+        Enum.filter(configs, fn %{"group" => group, "key" => key} ->
+          group == ":pleroma" and key == ":instance"
+        end)
+
+      assert instance_config["db"] == [":name"]
+    end
+
+    test "merged default setting with db settings", %{conn: conn} do
+      config1 = insert(:config)
+      config2 = insert(:config)
+
+      config3 =
+        insert(:config,
+          value: [k1: :v1, k2: :v2]
+        )
+
+      %{"configs" => configs} =
+        conn
+        |> get("/api/pleroma/admin/config")
+        |> json_response_and_validate_schema(200)
+
+      assert length(configs) > 3
+
+      saved_configs = [config1, config2, config3]
+      keys = Enum.map(saved_configs, &inspect(&1.key))
+
+      received_configs =
+        Enum.filter(configs, fn %{"group" => group, "key" => key} ->
+          group == ":pleroma" and key in keys
+        end)
+
+      assert length(received_configs) == 3
+
+      db_keys =
+        config3.value
+        |> Keyword.keys()
+        |> ConfigDB.to_json_types()
+
+      keys = Enum.map(saved_configs -- [config3], &inspect(&1.key))
+
+      values = Enum.map(saved_configs, &ConfigDB.to_json_types(&1.value))
+
+      mapset_keys = MapSet.new(keys ++ db_keys)
+
+      Enum.each(received_configs, fn %{"value" => value, "db" => db} ->
+        db = MapSet.new(db)
+        assert MapSet.subset?(db, mapset_keys)
+
+        assert value in values
+      end)
+    end
+
+    test "subkeys with full update right merge", %{conn: conn} do
+      insert(:config,
+        key: ":emoji",
+        value: [groups: [a: 1, b: 2], key: [a: 1]]
+      )
+
+      insert(:config,
+        key: ":assets",
+        value: [mascots: [a: 1, b: 2], key: [a: 1]]
+      )
+
+      %{"configs" => configs} =
+        conn
+        |> get("/api/pleroma/admin/config")
+        |> json_response_and_validate_schema(200)
+
+      vals =
+        Enum.filter(configs, fn %{"group" => group, "key" => key} ->
+          group == ":pleroma" and key in [":emoji", ":assets"]
+        end)
+
+      emoji = Enum.find(vals, fn %{"key" => key} -> key == ":emoji" end)
+      assets = Enum.find(vals, fn %{"key" => key} -> key == ":assets" end)
+
+      emoji_val = ConfigDB.to_elixir_types(emoji["value"])
+      assets_val = ConfigDB.to_elixir_types(assets["value"])
+
+      assert emoji_val[:groups] == [a: 1, b: 2]
+      assert assets_val[:mascots] == [a: 1, b: 2]
+    end
+
+    test "with valid `admin_token` query parameter, skips OAuth scopes check" do
+      clear_config([:admin_token], "password123")
+
+      build_conn()
+      |> get("/api/pleroma/admin/config?admin_token=password123")
+      |> json_response_and_validate_schema(200)
+    end
+  end
+
+  test "POST /api/pleroma/admin/config with configdb disabled", %{conn: conn} do
+    clear_config(:configurable_from_database, false)
+
+    conn =
+      conn
+      |> put_req_header("content-type", "application/json")
+      |> post("/api/pleroma/admin/config", %{"configs" => []})
+
+    assert json_response_and_validate_schema(conn, 400) ==
+             %{"error" => "You must enable configurable_from_database in your config file."}
+  end
+
+  describe "POST /api/pleroma/admin/config" do
+    setup do
+      http = Application.get_env(:pleroma, :http)
+
+      on_exit(fn ->
+        Application.delete_env(:pleroma, :key1)
+        Application.delete_env(:pleroma, :key2)
+        Application.delete_env(:pleroma, :key3)
+        Application.delete_env(:pleroma, :key4)
+        Application.delete_env(:pleroma, :keyaa1)
+        Application.delete_env(:pleroma, :keyaa2)
+        Application.delete_env(:pleroma, Pleroma.Web.Endpoint.NotReal)
+        Application.delete_env(:pleroma, Pleroma.Captcha.NotReal)
+        Application.put_env(:pleroma, :http, http)
+        Application.put_env(:tesla, :adapter, Tesla.Mock)
+        Restarter.Pleroma.refresh()
+      end)
+    end
+
+    setup do: clear_config(:configurable_from_database, true)
+
+    @tag capture_log: true
+    test "create new config setting in db", %{conn: conn} do
+      ueberauth = Application.get_env(:ueberauth, Ueberauth)
+      on_exit(fn -> Application.put_env(:ueberauth, Ueberauth, ueberauth) end)
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{group: ":pleroma", key: ":key1", value: "value1"},
+            %{
+              group: ":ueberauth",
+              key: "Ueberauth",
+              value: [%{"tuple" => [":consumer_secret", "aaaa"]}]
+            },
+            %{
+              group: ":pleroma",
+              key: ":key2",
+              value: %{
+                ":nested_1" => "nested_value1",
+                ":nested_2" => [
+                  %{":nested_22" => "nested_value222"},
+                  %{":nested_33" => %{":nested_44" => "nested_444"}}
+                ]
+              }
+            },
+            %{
+              group: ":pleroma",
+              key: ":key3",
+              value: [
+                %{"nested_3" => ":nested_3", "nested_33" => "nested_33"},
+                %{"nested_4" => true}
+              ]
+            },
+            %{
+              group: ":pleroma",
+              key: ":key4",
+              value: %{":nested_5" => ":upload", "endpoint" => "https://example.com"}
+            },
+            %{
+              group: ":idna",
+              key: ":key5",
+              value: %{"tuple" => ["string", "Pleroma.Captcha.NotReal", []]}
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key1",
+                   "value" => "value1",
+                   "db" => [":key1"]
+                 },
+                 %{
+                   "group" => ":ueberauth",
+                   "key" => "Ueberauth",
+                   "value" => [%{"tuple" => [":consumer_secret", "aaaa"]}],
+                   "db" => [":consumer_secret"]
+                 },
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key2",
+                   "value" => %{
+                     ":nested_1" => "nested_value1",
+                     ":nested_2" => [
+                       %{":nested_22" => "nested_value222"},
+                       %{":nested_33" => %{":nested_44" => "nested_444"}}
+                     ]
+                   },
+                   "db" => [":key2"]
+                 },
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key3",
+                   "value" => [
+                     %{"nested_3" => ":nested_3", "nested_33" => "nested_33"},
+                     %{"nested_4" => true}
+                   ],
+                   "db" => [":key3"]
+                 },
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key4",
+                   "value" => %{"endpoint" => "https://example.com", ":nested_5" => ":upload"},
+                   "db" => [":key4"]
+                 },
+                 %{
+                   "group" => ":idna",
+                   "key" => ":key5",
+                   "value" => %{"tuple" => ["string", "Pleroma.Captcha.NotReal", []]},
+                   "db" => [":key5"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert Application.get_env(:pleroma, :key1) == "value1"
+
+      assert Application.get_env(:pleroma, :key2) == %{
+               nested_1: "nested_value1",
+               nested_2: [
+                 %{nested_22: "nested_value222"},
+                 %{nested_33: %{nested_44: "nested_444"}}
+               ]
+             }
+
+      assert Application.get_env(:pleroma, :key3) == [
+               %{"nested_3" => :nested_3, "nested_33" => "nested_33"},
+               %{"nested_4" => true}
+             ]
+
+      assert Application.get_env(:pleroma, :key4) == %{
+               "endpoint" => "https://example.com",
+               nested_5: :upload
+             }
+
+      assert Application.get_env(:idna, :key5) == {"string", Pleroma.Captcha.NotReal, []}
+    end
+
+    test "save configs setting without explicit key", %{conn: conn} do
+      level = Application.get_env(:quack, :level)
+      meta = Application.get_env(:quack, :meta)
+      webhook_url = Application.get_env(:quack, :webhook_url)
+
+      on_exit(fn ->
+        Application.put_env(:quack, :level, level)
+        Application.put_env(:quack, :meta, meta)
+        Application.put_env(:quack, :webhook_url, webhook_url)
+      end)
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              group: ":quack",
+              key: ":level",
+              value: ":info"
+            },
+            %{
+              group: ":quack",
+              key: ":meta",
+              value: [":none"]
+            },
+            %{
+              group: ":quack",
+              key: ":webhook_url",
+              value: "https://hooks.slack.com/services/KEY"
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":quack",
+                   "key" => ":level",
+                   "value" => ":info",
+                   "db" => [":level"]
+                 },
+                 %{
+                   "group" => ":quack",
+                   "key" => ":meta",
+                   "value" => [":none"],
+                   "db" => [":meta"]
+                 },
+                 %{
+                   "group" => ":quack",
+                   "key" => ":webhook_url",
+                   "value" => "https://hooks.slack.com/services/KEY",
+                   "db" => [":webhook_url"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert Application.get_env(:quack, :level) == :info
+      assert Application.get_env(:quack, :meta) == [:none]
+      assert Application.get_env(:quack, :webhook_url) == "https://hooks.slack.com/services/KEY"
+    end
+
+    test "saving config with partial update", %{conn: conn} do
+      insert(:config, key: ":key1", value: :erlang.term_to_binary(key1: 1, key2: 2))
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{group: ":pleroma", key: ":key1", value: [%{"tuple" => [":key3", 3]}]}
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key1",
+                   "value" => [
+                     %{"tuple" => [":key1", 1]},
+                     %{"tuple" => [":key2", 2]},
+                     %{"tuple" => [":key3", 3]}
+                   ],
+                   "db" => [":key1", ":key2", ":key3"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "saving config which need pleroma reboot", %{conn: conn} do
+      clear_config([:shout, :enabled], true)
+
+      assert conn
+             |> put_req_header("content-type", "application/json")
+             |> post(
+               "/api/pleroma/admin/config",
+               %{
+                 configs: [
+                   %{group: ":pleroma", key: ":shout", value: [%{"tuple" => [":enabled", true]}]}
+                 ]
+               }
+             )
+             |> json_response_and_validate_schema(200) == %{
+               "configs" => [
+                 %{
+                   "db" => [":enabled"],
+                   "group" => ":pleroma",
+                   "key" => ":shout",
+                   "value" => [%{"tuple" => [":enabled", true]}]
+                 }
+               ],
+               "need_reboot" => true
+             }
+
+      configs =
+        conn
+        |> get("/api/pleroma/admin/config")
+        |> json_response_and_validate_schema(200)
+
+      assert configs["need_reboot"]
+
+      capture_log(fn ->
+        assert conn |> get("/api/pleroma/admin/restart") |> json_response(200) ==
+                 %{}
+      end) =~ "pleroma restarted"
+
+      configs =
+        conn
+        |> get("/api/pleroma/admin/config")
+        |> json_response_and_validate_schema(200)
+
+      assert configs["need_reboot"] == false
+    end
+
+    test "update setting which need reboot, don't change reboot flag until reboot", %{conn: conn} do
+      clear_config([:shout, :enabled], true)
+
+      assert conn
+             |> put_req_header("content-type", "application/json")
+             |> post(
+               "/api/pleroma/admin/config",
+               %{
+                 configs: [
+                   %{group: ":pleroma", key: ":shout", value: [%{"tuple" => [":enabled", true]}]}
+                 ]
+               }
+             )
+             |> json_response_and_validate_schema(200) == %{
+               "configs" => [
+                 %{
+                   "db" => [":enabled"],
+                   "group" => ":pleroma",
+                   "key" => ":shout",
+                   "value" => [%{"tuple" => [":enabled", true]}]
+                 }
+               ],
+               "need_reboot" => true
+             }
+
+      assert conn
+             |> put_req_header("content-type", "application/json")
+             |> post("/api/pleroma/admin/config", %{
+               configs: [
+                 %{group: ":pleroma", key: ":key1", value: [%{"tuple" => [":key3", 3]}]}
+               ]
+             })
+             |> json_response_and_validate_schema(200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key1",
+                   "value" => [
+                     %{"tuple" => [":key3", 3]}
+                   ],
+                   "db" => [":key3"]
+                 }
+               ],
+               "need_reboot" => true
+             }
+
+      capture_log(fn ->
+        assert conn |> get("/api/pleroma/admin/restart") |> json_response(200) ==
+                 %{}
+      end) =~ "pleroma restarted"
+
+      configs =
+        conn
+        |> get("/api/pleroma/admin/config")
+        |> json_response_and_validate_schema(200)
+
+      assert configs["need_reboot"] == false
+    end
+
+    test "saving config with nested merge", %{conn: conn} do
+      insert(:config, key: :key1, value: [key1: 1, key2: [k1: 1, k2: 2]])
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              group: ":pleroma",
+              key: ":key1",
+              value: [
+                %{"tuple" => [":key3", 3]},
+                %{
+                  "tuple" => [
+                    ":key2",
+                    [
+                      %{"tuple" => [":k2", 1]},
+                      %{"tuple" => [":k3", 3]}
+                    ]
+                  ]
+                }
+              ]
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key1",
+                   "value" => [
+                     %{"tuple" => [":key1", 1]},
+                     %{"tuple" => [":key3", 3]},
+                     %{
+                       "tuple" => [
+                         ":key2",
+                         [
+                           %{"tuple" => [":k1", 1]},
+                           %{"tuple" => [":k2", 1]},
+                           %{"tuple" => [":k3", 3]}
+                         ]
+                       ]
+                     }
+                   ],
+                   "db" => [":key1", ":key3", ":key2"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "saving special atoms", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          "configs" => [
+            %{
+              "group" => ":pleroma",
+              "key" => ":key1",
+              "value" => [
+                %{
+                  "tuple" => [
+                    ":ssl_options",
+                    [%{"tuple" => [":versions", [":tlsv1", ":tlsv1.1", ":tlsv1.2"]]}]
+                  ]
+                }
+              ]
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":key1",
+                   "value" => [
+                     %{
+                       "tuple" => [
+                         ":ssl_options",
+                         [%{"tuple" => [":versions", [":tlsv1", ":tlsv1.1", ":tlsv1.2"]]}]
+                       ]
+                     }
+                   ],
+                   "db" => [":ssl_options"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert Application.get_env(:pleroma, :key1) == [
+               ssl_options: [versions: [:tlsv1, :"tlsv1.1", :"tlsv1.2"]]
+             ]
+    end
+
+    test "saving full setting if value is in full_key_update list", %{conn: conn} do
+      backends = Application.get_env(:logger, :backends)
+      on_exit(fn -> Application.put_env(:logger, :backends, backends) end)
+
+      insert(:config,
+        group: :logger,
+        key: :backends,
+        value: []
+      )
+
+      Pleroma.Config.TransferTask.load_and_update_env([], false)
+
+      assert Application.get_env(:logger, :backends) == []
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              group: ":logger",
+              key: ":backends",
+              value: [":console"]
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":logger",
+                   "key" => ":backends",
+                   "value" => [
+                     ":console"
+                   ],
+                   "db" => [":backends"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert Application.get_env(:logger, :backends) == [
+               :console
+             ]
+    end
+
+    test "saving full setting if value is not keyword", %{conn: conn} do
+      insert(:config,
+        group: :tesla,
+        key: :adapter,
+        value: Tesla.Adapter.Hackey
+      )
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{group: ":tesla", key: ":adapter", value: "Tesla.Adapter.Httpc"}
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":tesla",
+                   "key" => ":adapter",
+                   "value" => "Tesla.Adapter.Httpc",
+                   "db" => [":adapter"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "update config setting & delete with fallback to default value", %{
+      conn: conn,
+      admin: admin,
+      token: token
+    } do
+      ueberauth = Application.get_env(:ueberauth, Ueberauth)
+      insert(:config, key: :keyaa1)
+      insert(:config, key: :keyaa2)
+
+      config3 =
+        insert(:config,
+          group: :ueberauth,
+          key: Ueberauth
+        )
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{group: ":pleroma", key: ":keyaa1", value: "another_value"},
+            %{group: ":pleroma", key: ":keyaa2", value: "another_value"}
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":keyaa1",
+                   "value" => "another_value",
+                   "db" => [":keyaa1"]
+                 },
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":keyaa2",
+                   "value" => "another_value",
+                   "db" => [":keyaa2"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert Application.get_env(:pleroma, :keyaa1) == "another_value"
+      assert Application.get_env(:pleroma, :keyaa2) == "another_value"
+      assert Application.get_env(:ueberauth, Ueberauth) == config3.value
+
+      conn =
+        build_conn()
+        |> assign(:user, admin)
+        |> assign(:token, token)
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{group: ":pleroma", key: ":keyaa2", delete: true},
+            %{
+              group: ":ueberauth",
+              key: "Ueberauth",
+              delete: true
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [],
+               "need_reboot" => false
+             }
+
+      assert Application.get_env(:ueberauth, Ueberauth) == ueberauth
+      refute Keyword.has_key?(Application.get_all_env(:pleroma), :keyaa2)
+    end
+
+    test "common config example", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              "group" => ":pleroma",
+              "key" => "Pleroma.Captcha.NotReal",
+              "value" => [
+                %{"tuple" => [":enabled", false]},
+                %{"tuple" => [":method", "Pleroma.Captcha.Kocaptcha"]},
+                %{"tuple" => [":seconds_valid", 60]},
+                %{"tuple" => [":path", ""]},
+                %{"tuple" => [":key1", nil]},
+                %{"tuple" => [":partial_chain", "&:hackney_connect.partial_chain/1"]},
+                %{"tuple" => [":regex1", "~r/https:\/\/example.com/"]},
+                %{"tuple" => [":regex2", "~r/https:\/\/example.com/u"]},
+                %{"tuple" => [":regex3", "~r/https:\/\/example.com/i"]},
+                %{"tuple" => [":regex4", "~r/https:\/\/example.com/s"]},
+                %{"tuple" => [":name", "Pleroma"]}
+              ]
+            }
+          ]
+        })
+
+      assert Config.get([Pleroma.Captcha.NotReal, :name]) == "Pleroma"
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => "Pleroma.Captcha.NotReal",
+                   "value" => [
+                     %{"tuple" => [":enabled", false]},
+                     %{"tuple" => [":method", "Pleroma.Captcha.Kocaptcha"]},
+                     %{"tuple" => [":seconds_valid", 60]},
+                     %{"tuple" => [":path", ""]},
+                     %{"tuple" => [":key1", nil]},
+                     %{"tuple" => [":partial_chain", "&:hackney_connect.partial_chain/1"]},
+                     %{"tuple" => [":regex1", "~r/https:\\/\\/example.com/"]},
+                     %{"tuple" => [":regex2", "~r/https:\\/\\/example.com/u"]},
+                     %{"tuple" => [":regex3", "~r/https:\\/\\/example.com/i"]},
+                     %{"tuple" => [":regex4", "~r/https:\\/\\/example.com/s"]},
+                     %{"tuple" => [":name", "Pleroma"]}
+                   ],
+                   "db" => [
+                     ":enabled",
+                     ":method",
+                     ":seconds_valid",
+                     ":path",
+                     ":key1",
+                     ":partial_chain",
+                     ":regex1",
+                     ":regex2",
+                     ":regex3",
+                     ":regex4",
+                     ":name"
+                   ]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "tuples with more than two values", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              "group" => ":pleroma",
+              "key" => "Pleroma.Web.Endpoint.NotReal",
+              "value" => [
+                %{
+                  "tuple" => [
+                    ":http",
+                    [
+                      %{
+                        "tuple" => [
+                          ":key2",
+                          [
+                            %{
+                              "tuple" => [
+                                ":_",
+                                [
+                                  %{
+                                    "tuple" => [
+                                      "/api/v1/streaming",
+                                      "Pleroma.Web.MastodonAPI.WebsocketHandler",
+                                      []
+                                    ]
+                                  },
+                                  %{
+                                    "tuple" => [
+                                      "/websocket",
+                                      "Phoenix.Endpoint.CowboyWebSocket",
+                                      %{
+                                        "tuple" => [
+                                          "Phoenix.Transports.WebSocket",
+                                          %{
+                                            "tuple" => [
+                                              "Pleroma.Web.Endpoint",
+                                              "Pleroma.Web.UserSocket",
+                                              []
+                                            ]
+                                          }
+                                        ]
+                                      }
+                                    ]
+                                  },
+                                  %{
+                                    "tuple" => [
+                                      ":_",
+                                      "Phoenix.Endpoint.Cowboy2Handler",
+                                      %{"tuple" => ["Pleroma.Web.Endpoint", []]}
+                                    ]
+                                  }
+                                ]
+                              ]
+                            }
+                          ]
+                        ]
+                      }
+                    ]
+                  ]
+                }
+              ]
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => "Pleroma.Web.Endpoint.NotReal",
+                   "value" => [
+                     %{
+                       "tuple" => [
+                         ":http",
+                         [
+                           %{
+                             "tuple" => [
+                               ":key2",
+                               [
+                                 %{
+                                   "tuple" => [
+                                     ":_",
+                                     [
+                                       %{
+                                         "tuple" => [
+                                           "/api/v1/streaming",
+                                           "Pleroma.Web.MastodonAPI.WebsocketHandler",
+                                           []
+                                         ]
+                                       },
+                                       %{
+                                         "tuple" => [
+                                           "/websocket",
+                                           "Phoenix.Endpoint.CowboyWebSocket",
+                                           %{
+                                             "tuple" => [
+                                               "Phoenix.Transports.WebSocket",
+                                               %{
+                                                 "tuple" => [
+                                                   "Pleroma.Web.Endpoint",
+                                                   "Pleroma.Web.UserSocket",
+                                                   []
+                                                 ]
+                                               }
+                                             ]
+                                           }
+                                         ]
+                                       },
+                                       %{
+                                         "tuple" => [
+                                           ":_",
+                                           "Phoenix.Endpoint.Cowboy2Handler",
+                                           %{"tuple" => ["Pleroma.Web.Endpoint", []]}
+                                         ]
+                                       }
+                                     ]
+                                   ]
+                                 }
+                               ]
+                             ]
+                           }
+                         ]
+                       ]
+                     }
+                   ],
+                   "db" => [":http"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "settings with nesting map", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              "group" => ":pleroma",
+              "key" => ":key1",
+              "value" => [
+                %{"tuple" => [":key2", "some_val"]},
+                %{
+                  "tuple" => [
+                    ":key3",
+                    %{
+                      ":max_options" => 20,
+                      ":max_option_chars" => 200,
+                      ":min_expiration" => 0,
+                      ":max_expiration" => 31_536_000,
+                      "nested" => %{
+                        ":max_options" => 20,
+                        ":max_option_chars" => 200,
+                        ":min_expiration" => 0,
+                        ":max_expiration" => 31_536_000
+                      }
+                    }
+                  ]
+                }
+              ]
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) ==
+               %{
+                 "configs" => [
+                   %{
+                     "group" => ":pleroma",
+                     "key" => ":key1",
+                     "value" => [
+                       %{"tuple" => [":key2", "some_val"]},
+                       %{
+                         "tuple" => [
+                           ":key3",
+                           %{
+                             ":max_expiration" => 31_536_000,
+                             ":max_option_chars" => 200,
+                             ":max_options" => 20,
+                             ":min_expiration" => 0,
+                             "nested" => %{
+                               ":max_expiration" => 31_536_000,
+                               ":max_option_chars" => 200,
+                               ":max_options" => 20,
+                               ":min_expiration" => 0
+                             }
+                           }
+                         ]
+                       }
+                     ],
+                     "db" => [":key2", ":key3"]
+                   }
+                 ],
+                 "need_reboot" => false
+               }
+    end
+
+    test "value as map", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              "group" => ":pleroma",
+              "key" => ":key1",
+              "value" => %{"key" => "some_val"}
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) ==
+               %{
+                 "configs" => [
+                   %{
+                     "group" => ":pleroma",
+                     "key" => ":key1",
+                     "value" => %{"key" => "some_val"},
+                     "db" => [":key1"]
+                   }
+                 ],
+                 "need_reboot" => false
+               }
+    end
+
+    test "queues key as atom", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              "group" => ":oban",
+              "key" => ":queues",
+              "value" => [
+                %{"tuple" => [":federator_incoming", 50]},
+                %{"tuple" => [":federator_outgoing", 50]},
+                %{"tuple" => [":web_push", 50]},
+                %{"tuple" => [":mailer", 10]},
+                %{"tuple" => [":transmogrifier", 20]},
+                %{"tuple" => [":scheduled_activities", 10]},
+                %{"tuple" => [":background", 5]}
+              ]
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":oban",
+                   "key" => ":queues",
+                   "value" => [
+                     %{"tuple" => [":federator_incoming", 50]},
+                     %{"tuple" => [":federator_outgoing", 50]},
+                     %{"tuple" => [":web_push", 50]},
+                     %{"tuple" => [":mailer", 10]},
+                     %{"tuple" => [":transmogrifier", 20]},
+                     %{"tuple" => [":scheduled_activities", 10]},
+                     %{"tuple" => [":background", 5]}
+                   ],
+                   "db" => [
+                     ":federator_incoming",
+                     ":federator_outgoing",
+                     ":web_push",
+                     ":mailer",
+                     ":transmogrifier",
+                     ":scheduled_activities",
+                     ":background"
+                   ]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "delete part of settings by atom subkeys", %{conn: conn} do
+      insert(:config,
+        key: :keyaa1,
+        value: [subkey1: "val1", subkey2: "val2", subkey3: "val3"]
+      )
+
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              group: ":pleroma",
+              key: ":keyaa1",
+              subkeys: [":subkey1", ":subkey3"],
+              delete: true
+            }
+          ]
+        })
+
+      assert json_response_and_validate_schema(conn, 200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":keyaa1",
+                   "value" => [%{"tuple" => [":subkey2", "val2"]}],
+                   "db" => [":subkey2"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "proxy tuple localhost", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              group: ":pleroma",
+              key: ":http",
+              value: [
+                %{"tuple" => [":proxy_url", %{"tuple" => [":socks5", "localhost", 1234]}]}
+              ]
+            }
+          ]
+        })
+
+      assert %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":http",
+                   "value" => value,
+                   "db" => db
+                 }
+               ]
+             } = json_response_and_validate_schema(conn, 200)
+
+      assert %{"tuple" => [":proxy_url", %{"tuple" => [":socks5", "localhost", 1234]}]} in value
+      assert ":proxy_url" in db
+    end
+
+    test "proxy tuple domain", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              group: ":pleroma",
+              key: ":http",
+              value: [
+                %{"tuple" => [":proxy_url", %{"tuple" => [":socks5", "domain.com", 1234]}]}
+              ]
+            }
+          ]
+        })
+
+      assert %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":http",
+                   "value" => value,
+                   "db" => db
+                 }
+               ]
+             } = json_response_and_validate_schema(conn, 200)
+
+      assert %{"tuple" => [":proxy_url", %{"tuple" => [":socks5", "domain.com", 1234]}]} in value
+      assert ":proxy_url" in db
+    end
+
+    test "proxy tuple ip", %{conn: conn} do
+      conn =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/pleroma/admin/config", %{
+          configs: [
+            %{
+              group: ":pleroma",
+              key: ":http",
+              value: [
+                %{"tuple" => [":proxy_url", %{"tuple" => [":socks5", "127.0.0.1", 1234]}]}
+              ]
+            }
+          ]
+        })
+
+      assert %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => ":http",
+                   "value" => value,
+                   "db" => db
+                 }
+               ]
+             } = json_response_and_validate_schema(conn, 200)
+
+      assert %{"tuple" => [":proxy_url", %{"tuple" => [":socks5", "127.0.0.1", 1234]}]} in value
+      assert ":proxy_url" in db
+    end
+
+    @tag capture_log: true
+    test "doesn't set keys not in the whitelist", %{conn: conn} do
+      clear_config(:database_config_whitelist, [
+        {:pleroma, :key1},
+        {:pleroma, :key2},
+        {:pleroma, Pleroma.Captcha.NotReal},
+        {:not_real}
+      ])
+
+      conn
+      |> put_req_header("content-type", "application/json")
+      |> post("/api/pleroma/admin/config", %{
+        configs: [
+          %{group: ":pleroma", key: ":key1", value: "value1"},
+          %{group: ":pleroma", key: ":key2", value: "value2"},
+          %{group: ":pleroma", key: ":key3", value: "value3"},
+          %{group: ":pleroma", key: "Pleroma.Web.Endpoint.NotReal", value: "value4"},
+          %{group: ":pleroma", key: "Pleroma.Captcha.NotReal", value: "value5"},
+          %{group: ":not_real", key: ":anything", value: "value6"}
+        ]
+      })
+
+      assert Application.get_env(:pleroma, :key1) == "value1"
+      assert Application.get_env(:pleroma, :key2) == "value2"
+      assert Application.get_env(:pleroma, :key3) == nil
+      assert Application.get_env(:pleroma, Pleroma.Web.Endpoint.NotReal) == nil
+      assert Application.get_env(:pleroma, Pleroma.Captcha.NotReal) == "value5"
+      assert Application.get_env(:not_real, :anything) == "value6"
+    end
+
+    test "args for Pleroma.Upload.Filter.Mogrify with custom tuples", %{conn: conn} do
+      clear_config(Pleroma.Upload.Filter.Mogrify)
+
+      assert conn
+             |> put_req_header("content-type", "application/json")
+             |> post("/api/pleroma/admin/config", %{
+               configs: [
+                 %{
+                   group: ":pleroma",
+                   key: "Pleroma.Upload.Filter.Mogrify",
+                   value: [
+                     %{"tuple" => [":args", ["auto-orient", "strip"]]}
+                   ]
+                 }
+               ]
+             })
+             |> json_response_and_validate_schema(200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => "Pleroma.Upload.Filter.Mogrify",
+                   "value" => [
+                     %{"tuple" => [":args", ["auto-orient", "strip"]]}
+                   ],
+                   "db" => [":args"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert Config.get(Pleroma.Upload.Filter.Mogrify) == [args: ["auto-orient", "strip"]]
+
+      assert conn
+             |> put_req_header("content-type", "application/json")
+             |> post("/api/pleroma/admin/config", %{
+               configs: [
+                 %{
+                   group: ":pleroma",
+                   key: "Pleroma.Upload.Filter.Mogrify",
+                   value: [
+                     %{
+                       "tuple" => [
+                         ":args",
+                         [
+                           "auto-orient",
+                           "strip",
+                           "{\"implode\", \"1\"}",
+                           "{\"resize\", \"3840x1080>\"}"
+                         ]
+                       ]
+                     }
+                   ]
+                 }
+               ]
+             })
+             |> json_response(200) == %{
+               "configs" => [
+                 %{
+                   "group" => ":pleroma",
+                   "key" => "Pleroma.Upload.Filter.Mogrify",
+                   "value" => [
+                     %{
+                       "tuple" => [
+                         ":args",
+                         [
+                           "auto-orient",
+                           "strip",
+                           "{\"implode\", \"1\"}",
+                           "{\"resize\", \"3840x1080>\"}"
+                         ]
+                       ]
+                     }
+                   ],
+                   "db" => [":args"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+
+      assert Config.get(Pleroma.Upload.Filter.Mogrify) == [
+               args: ["auto-orient", "strip", {"implode", "1"}, {"resize", "3840x1080>"}]
+             ]
+    end
+
+    test "enables the welcome messages", %{conn: conn} do
+      clear_config([:welcome])
+
+      params = %{
+        "group" => ":pleroma",
+        "key" => ":welcome",
+        "value" => [
+          %{
+            "tuple" => [
+              ":direct_message",
+              [
+                %{"tuple" => [":enabled", true]},
+                %{"tuple" => [":message", "Welcome to Pleroma!"]},
+                %{"tuple" => [":sender_nickname", "pleroma"]}
+              ]
+            ]
+          },
+          %{
+            "tuple" => [
+              ":chat_message",
+              [
+                %{"tuple" => [":enabled", true]},
+                %{"tuple" => [":message", "Welcome to Pleroma!"]},
+                %{"tuple" => [":sender_nickname", "pleroma"]}
+              ]
+            ]
+          },
+          %{
+            "tuple" => [
+              ":email",
+              [
+                %{"tuple" => [":enabled", true]},
+                %{"tuple" => [":sender", %{"tuple" => ["pleroma@dev.dev", "Pleroma"]}]},
+                %{"tuple" => [":subject", "Welcome to <%= instance_name %>!"]},
+                %{"tuple" => [":html", "Welcome to <%= instance_name %>!"]},
+                %{"tuple" => [":text", "Welcome to <%= instance_name %>!"]}
+              ]
+            ]
+          }
+        ]
+      }
+
+      refute Pleroma.User.WelcomeEmail.enabled?()
+      refute Pleroma.User.WelcomeMessage.enabled?()
+      refute Pleroma.User.WelcomeChatMessage.enabled?()
+
+      res =
+        assert conn
+               |> put_req_header("content-type", "application/json")
+               |> post("/api/pleroma/admin/config", %{"configs" => [params]})
+               |> json_response_and_validate_schema(200)
+
+      assert Pleroma.User.WelcomeEmail.enabled?()
+      assert Pleroma.User.WelcomeMessage.enabled?()
+      assert Pleroma.User.WelcomeChatMessage.enabled?()
+
+      assert res == %{
+               "configs" => [
+                 %{
+                   "db" => [":direct_message", ":chat_message", ":email"],
+                   "group" => ":pleroma",
+                   "key" => ":welcome",
+                   "value" => params["value"]
+                 }
+               ],
+               "need_reboot" => false
+             }
+    end
+
+    test "custom instance thumbnail", %{conn: conn} do
+      clear_config([:instance])
+
+      params = %{
+        "group" => ":pleroma",
+        "key" => ":instance",
+        "value" => [
+          %{
+            "tuple" => [
+              ":instance_thumbnail",
+              "https://example.com/media/new_thumbnail.jpg"
+            ]
+          }
+        ]
+      }
+
+      assert conn
+             |> put_req_header("content-type", "application/json")
+             |> post("/api/pleroma/admin/config", %{"configs" => [params]})
+             |> json_response_and_validate_schema(200) ==
+               %{
+                 "configs" => [
+                   %{
+                     "db" => [":instance_thumbnail"],
+                     "group" => ":pleroma",
+                     "key" => ":instance",
+                     "value" => params["value"]
+                   }
+                 ],
+                 "need_reboot" => false
+               }
+
+      assert conn
+             |> get("/api/v1/instance")
+             |> json_response_and_validate_schema(200)
+             |> Map.take(["thumbnail"]) ==
+               %{"thumbnail" => "https://example.com/media/new_thumbnail.jpg"}
+    end
+
+    test "Concurrent Limiter", %{conn: conn} do
+      clear_config([ConcurrentLimiter])
+
+      params = %{
+        "group" => ":pleroma",
+        "key" => "ConcurrentLimiter",
+        "value" => [
+          %{
+            "tuple" => [
+              "Pleroma.Web.RichMedia.Helpers",
+              [
+                %{"tuple" => [":max_running", 6]},
+                %{"tuple" => [":max_waiting", 6]}
+              ]
+            ]
+          },
+          %{
+            "tuple" => [
+              "Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicy",
+              [
+                %{"tuple" => [":max_running", 7]},
+                %{"tuple" => [":max_waiting", 7]}
+              ]
+            ]
+          }
+        ]
+      }
+
+      assert conn
+             |> put_req_header("content-type", "application/json")
+             |> post("/api/pleroma/admin/config", %{"configs" => [params]})
+             |> json_response_and_validate_schema(200)
+    end
+  end
+
+  describe "GET /api/pleroma/admin/config/descriptions" do
+    test "structure", %{conn: conn} do
+      conn = get(conn, "/api/pleroma/admin/config/descriptions")
+
+      assert [child | _others] = json_response_and_validate_schema(conn, 200)
+
+      assert child["children"]
+      assert child["key"]
+      assert String.starts_with?(child["group"], ":")
+      assert child["description"]
+    end
+
+    test "filters by database configuration whitelist", %{conn: conn} do
+      clear_config(:database_config_whitelist, [
+        {:pleroma, :instance},
+        {:pleroma, :activitypub},
+        {:pleroma, Pleroma.Upload}
+      ])
+
+      conn = get(conn, "/api/pleroma/admin/config/descriptions")
+
+      children = json_response_and_validate_schema(conn, 200)
+
+      assert length(children) == 3
+
+      assert Enum.count(children, fn c -> c["group"] == ":pleroma" end) == 3
+
+      instance = Enum.find(children, fn c -> c["key"] == ":instance" end)
+      assert instance["children"]
+
+      activitypub = Enum.find(children, fn c -> c["key"] == ":activitypub" end)
+      assert activitypub["children"]
+
+      web_endpoint = Enum.find(children, fn c -> c["key"] == "Pleroma.Upload" end)
+      assert web_endpoint["children"]
+    end
+  end
+end
diff --git a/test/pleroma/web/common_api_test.exs b/test/pleroma/web/common_api_test.exs
index 33709c8f3..666b9612b 100644
--- a/test/pleroma/web/common_api_test.exs
+++ b/test/pleroma/web/common_api_test.exs
@@ -7,11 +7,13 @@ defmodule Pleroma.Web.CommonAPITest do
   use Pleroma.DataCase
 
   alias Pleroma.Activity
+  alias Pleroma.Chat
   alias Pleroma.Conversation.Participation
   alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.Repo
   alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Transmogrifier
   alias Pleroma.Web.ActivityPub.Visibility
   alias Pleroma.Web.AdminAPI.AccountView
@@ -115,6 +117,173 @@ defmodule Pleroma.Web.CommonAPITest do
     end
   end
 
+  describe "posting chat messages" do
+    setup do: clear_config([:instance, :chat_limit])
+
+    test "it posts a self-chat" do
+      author = insert(:user)
+      recipient = author
+
+      {:ok, activity} =
+        CommonAPI.post_chat_message(
+          author,
+          recipient,
+          "remember to buy milk when milk truk arive"
+        )
+
+      assert activity.data["type"] == "Create"
+    end
+
+    test "it posts a chat message without content but with an attachment" do
+      author = insert(:user)
+      recipient = insert(:user)
+
+      file = %Plug.Upload{
+        content_type: "image/jpeg",
+        path: Path.absname("test/fixtures/image.jpg"),
+        filename: "an_image.jpg"
+      }
+
+      {:ok, upload} = ActivityPub.upload(file, actor: author.ap_id)
+
+      with_mocks([
+        {
+          Pleroma.Web.Streamer,
+          [],
+          [
+            stream: fn _, _ ->
+              nil
+            end
+          ]
+        },
+        {
+          Pleroma.Web.Push,
+          [],
+          [
+            send: fn _ -> nil end
+          ]
+        }
+      ]) do
+        {:ok, activity} =
+          CommonAPI.post_chat_message(
+            author,
+            recipient,
+            nil,
+            media_id: upload.id
+          )
+
+        notification =
+          Notification.for_user_and_activity(recipient, activity)
+          |> Repo.preload(:activity)
+
+        assert called(Pleroma.Web.Push.send(notification))
+        assert called(Pleroma.Web.Streamer.stream(["user", "user:notification"], notification))
+        assert called(Pleroma.Web.Streamer.stream(["user", "user:pleroma_chat"], :_))
+
+        assert activity
+      end
+    end
+
+    test "it adds html newlines" do
+      author = insert(:user)
+      recipient = insert(:user)
+
+      other_user = insert(:user)
+
+      {:ok, activity} =
+        CommonAPI.post_chat_message(
+          author,
+          recipient,
+          "uguu\nuguuu"
+        )
+
+      assert other_user.ap_id not in activity.recipients
+
+      object = Object.normalize(activity, fetch: false)
+
+      assert object.data["content"] == "uguu<br/>uguuu"
+    end
+
+    test "it linkifies" do
+      author = insert(:user)
+      recipient = insert(:user)
+
+      other_user = insert(:user)
+
+      {:ok, activity} =
+        CommonAPI.post_chat_message(
+          author,
+          recipient,
+          "https://example.org is the site of @#{other_user.nickname} #2hu"
+        )
+
+      assert other_user.ap_id not in activity.recipients
+
+      object = Object.normalize(activity, fetch: false)
+
+      assert object.data["content"] ==
+               "<a href=\"https://example.org\" rel=\"ugc\">https://example.org</a> is the site of <span class=\"h-card\"><a class=\"u-url mention\" data-user=\"#{other_user.id}\" href=\"#{other_user.ap_id}\" rel=\"ugc\">@<span>#{other_user.nickname}</span></a></span> <a class=\"hashtag\" data-tag=\"2hu\" href=\"http://localhost:4001/tag/2hu\">#2hu</a>"
+    end
+
+    test "it posts a chat message" do
+      author = insert(:user)
+      recipient = insert(:user)
+
+      {:ok, activity} =
+        CommonAPI.post_chat_message(
+          author,
+          recipient,
+          "a test message <script>alert('uuu')</script> :firefox:"
+        )
+
+      assert activity.data["type"] == "Create"
+      assert activity.local
+      object = Object.normalize(activity, fetch: false)
+
+      assert object.data["type"] == "ChatMessage"
+      assert object.data["to"] == [recipient.ap_id]
+
+      assert object.data["content"] ==
+               "a test message &lt;script&gt;alert(&#39;uuu&#39;)&lt;/script&gt; :firefox:"
+
+      assert object.data["emoji"] == %{
+               "firefox" => "http://localhost:4001/emoji/Firefox.gif"
+             }
+
+      assert Chat.get(author.id, recipient.ap_id)
+      assert Chat.get(recipient.id, author.ap_id)
+
+      assert :ok == Pleroma.Web.Federator.perform(:publish, activity)
+    end
+
+    test "it reject messages over the local limit" do
+      clear_config([:instance, :chat_limit], 2)
+
+      author = insert(:user)
+      recipient = insert(:user)
+
+      {:error, message} =
+        CommonAPI.post_chat_message(
+          author,
+          recipient,
+          "123"
+        )
+
+      assert message == :content_too_long
+    end
+
+    test "it reject messages via MRF" do
+      clear_config([:mrf_keyword, :reject], ["GNO"])
+      clear_config([:mrf, :policies], [Pleroma.Web.ActivityPub.MRF.KeywordPolicy])
+
+      author = insert(:user)
+      recipient = insert(:user)
+
+      assert {:reject, "[KeywordPolicy] Matches with rejected keyword"} ==
+               CommonAPI.post_chat_message(author, recipient, "GNO/Linux")
+    end
+  end
+
   describe "unblocking" do
     test "it works even without an existing block activity" do
       blocked = insert(:user)
diff --git a/test/pleroma/web/mastodon_api/controllers/account_controller_test.exs b/test/pleroma/web/mastodon_api/controllers/account_controller_test.exs
index bbede76e9..f981cd996 100644
--- a/test/pleroma/web/mastodon_api/controllers/account_controller_test.exs
+++ b/test/pleroma/web/mastodon_api/controllers/account_controller_test.exs
@@ -1711,6 +1711,7 @@ defmodule Pleroma.Web.MastodonAPI.AccountControllerTest do
       response = json_response_and_validate_schema(conn, 200)
 
       assert %{"id" => id, "source" => %{"privacy" => "public"}} = response
+      assert response["pleroma"]["chat_token"]
       assert response["pleroma"]["unread_notifications_count"] == 6
       assert id == to_string(user.id)
     end
diff --git a/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs b/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs
index bc3d35819..b3c531afc 100644
--- a/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs
+++ b/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs
@@ -39,6 +39,7 @@ defmodule Pleroma.Web.MastodonAPI.InstanceControllerTest do
              "background_upload_limit" => _,
              "banner_upload_limit" => _,
              "background_image" => from_config_background,
+             "shout_limit" => _,
              "description_limit" => _
            } = result
 
diff --git a/test/pleroma/web/mastodon_api/controllers/notification_controller_test.exs b/test/pleroma/web/mastodon_api/controllers/notification_controller_test.exs
index f463bfae1..650783587 100644
--- a/test/pleroma/web/mastodon_api/controllers/notification_controller_test.exs
+++ b/test/pleroma/web/mastodon_api/controllers/notification_controller_test.exs
@@ -52,6 +52,27 @@ defmodule Pleroma.Web.MastodonAPI.NotificationControllerTest do
     assert response == expected_response
   end
 
+  test "by default, does not contain pleroma:chat_mention" do
+    %{user: user, conn: conn} = oauth_access(["read:notifications"])
+    other_user = insert(:user)
+
+    {:ok, _activity} = CommonAPI.post_chat_message(other_user, user, "hey")
+
+    result =
+      conn
+      |> get("/api/v1/notifications")
+      |> json_response_and_validate_schema(200)
+
+    assert [] == result
+
+    result =
+      conn
+      |> get("/api/v1/notifications?include_types[]=pleroma:chat_mention")
+      |> json_response_and_validate_schema(200)
+
+    assert [_] = result
+  end
+
   test "by default, does not contain pleroma:report" do
     %{user: user, conn: conn} = oauth_access(["read:notifications"])
     other_user = insert(:user)
diff --git a/test/pleroma/web/mastodon_api/controllers/subscription_controller_test.exs b/test/pleroma/web/mastodon_api/controllers/subscription_controller_test.exs
index 1335656b4..5a3f93d2d 100644
--- a/test/pleroma/web/mastodon_api/controllers/subscription_controller_test.exs
+++ b/test/pleroma/web/mastodon_api/controllers/subscription_controller_test.exs
@@ -113,6 +113,7 @@ defmodule Pleroma.Web.MastodonAPI.SubscriptionControllerTest do
               "favourite" => true,
               "follow" => true,
               "reblog" => true,
+              "pleroma:chat_mention" => true,
               "pleroma:emoji_reaction" => true
             }
           },
@@ -128,6 +129,7 @@ defmodule Pleroma.Web.MastodonAPI.SubscriptionControllerTest do
                  "favourite" => true,
                  "follow" => true,
                  "reblog" => true,
+                 "pleroma:chat_mention" => true,
                  "pleroma:emoji_reaction" => true
                },
                "endpoint" => subscription.endpoint,
@@ -183,6 +185,7 @@ defmodule Pleroma.Web.MastodonAPI.SubscriptionControllerTest do
               "favourite" => true,
               "follow" => true,
               "reblog" => true,
+              "pleroma:chat_mention" => true,
               "pleroma:emoji_reaction" => true
             }
           }
@@ -201,6 +204,7 @@ defmodule Pleroma.Web.MastodonAPI.SubscriptionControllerTest do
               "favourite" => false,
               "follow" => false,
               "reblog" => false,
+              "pleroma:chat_mention" => false,
               "pleroma:emoji_reaction" => false
             }
           }
@@ -213,6 +217,7 @@ defmodule Pleroma.Web.MastodonAPI.SubscriptionControllerTest do
           "favourite" => false,
           "follow" => false,
           "reblog" => false,
+          "pleroma:chat_mention" => false,
           "pleroma:emoji_reaction" => false
         },
         "endpoint" => "https://example.com/example/1234",
diff --git a/test/pleroma/web/mastodon_api/update_credentials_test.exs b/test/pleroma/web/mastodon_api/update_credentials_test.exs
index e9b8825bf..212ba7faf 100644
--- a/test/pleroma/web/mastodon_api/update_credentials_test.exs
+++ b/test/pleroma/web/mastodon_api/update_credentials_test.exs
@@ -104,6 +104,13 @@ defmodule Pleroma.Web.MastodonAPI.UpdateCredentialsTest do
       assert user_data["locked"] == true
     end
 
+    test "updates the user's chat acceptance status", %{conn: conn} do
+      conn = patch(conn, "/api/v1/accounts/update_credentials", %{accepts_chat_messages: "false"})
+
+      assert user_data = json_response_and_validate_schema(conn, 200)
+      assert user_data["pleroma"]["accepts_chat_messages"] == false
+    end
+
     test "updates the user's allow_following_move", %{user: user, conn: conn} do
       assert user.allow_following_move == true
 
diff --git a/test/pleroma/web/mastodon_api/views/account_view_test.exs b/test/pleroma/web/mastodon_api/views/account_view_test.exs
index c9036d67d..048f33e12 100644
--- a/test/pleroma/web/mastodon_api/views/account_view_test.exs
+++ b/test/pleroma/web/mastodon_api/views/account_view_test.exs
@@ -106,7 +106,8 @@ defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
         hide_followers_count: false,
         hide_follows_count: false,
         relationship: %{},
-        skip_thread_containment: false
+        skip_thread_containment: false,
+        accepts_chat_messages: nil
       }
     }
 
@@ -264,7 +265,8 @@ defmodule Pleroma.Web.MastodonAPI.AccountViewTest do
         hide_followers_count: false,
         hide_follows_count: false,
         relationship: %{},
-        skip_thread_containment: false
+        skip_thread_containment: false,
+        accepts_chat_messages: nil
       }
     }
 
diff --git a/test/pleroma/web/mastodon_api/views/notification_view_test.exs b/test/pleroma/web/mastodon_api/views/notification_view_test.exs
index 64d2c8a2e..40e4e584e 100644
--- a/test/pleroma/web/mastodon_api/views/notification_view_test.exs
+++ b/test/pleroma/web/mastodon_api/views/notification_view_test.exs
@@ -6,6 +6,8 @@ defmodule Pleroma.Web.MastodonAPI.NotificationViewTest do
   use Pleroma.DataCase
 
   alias Pleroma.Activity
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
   alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.Repo
@@ -20,6 +22,7 @@ defmodule Pleroma.Web.MastodonAPI.NotificationViewTest do
   alias Pleroma.Web.MastodonAPI.NotificationView
   alias Pleroma.Web.MastodonAPI.StatusView
   alias Pleroma.Web.MediaProxy
+  alias Pleroma.Web.PleromaAPI.Chat.MessageReferenceView
   import Pleroma.Factory
 
   defp test_notifications_rendering(notifications, user, expected_result) do
@@ -37,6 +40,30 @@ defmodule Pleroma.Web.MastodonAPI.NotificationViewTest do
     assert expected_result == result
   end
 
+  test "ChatMessage notification" do
+    user = insert(:user)
+    recipient = insert(:user)
+    {:ok, activity} = CommonAPI.post_chat_message(user, recipient, "what's up my dude")
+
+    {:ok, [notification]} = Notification.create_notifications(activity)
+
+    object = Object.normalize(activity, fetch: false)
+    chat = Chat.get(recipient.id, user.ap_id)
+
+    cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+    expected = %{
+      id: to_string(notification.id),
+      pleroma: %{is_seen: false, is_muted: false},
+      type: "pleroma:chat_mention",
+      account: AccountView.render("show.json", %{user: user, for: recipient}),
+      chat_message: MessageReferenceView.render("show.json", %{chat_message_reference: cm_ref}),
+      created_at: Utils.to_masto_date(notification.inserted_at)
+    }
+
+    test_notifications_rendering([notification], recipient, [expected])
+  end
+
   test "Mention notification" do
     user = insert(:user)
     mentioned_user = insert(:user)
diff --git a/test/pleroma/web/pleroma_api/controllers/chat_controller_test.exs b/test/pleroma/web/pleroma_api/controllers/chat_controller_test.exs
new file mode 100644
index 000000000..1114da242
--- /dev/null
+++ b/test/pleroma/web/pleroma_api/controllers/chat_controller_test.exs
@@ -0,0 +1,453 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+defmodule Pleroma.Web.PleromaAPI.ChatControllerTest do
+  use Pleroma.Web.ConnCase
+
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.Object
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.CommonAPI
+
+  import Pleroma.Factory
+
+  describe "POST /api/v1/pleroma/chats/:id/messages/:message_id/read" do
+    setup do: oauth_access(["write:chats"])
+
+    test "it marks one message as read", %{conn: conn, user: user} do
+      other_user = insert(:user)
+
+      {:ok, create} = CommonAPI.post_chat_message(other_user, user, "sup")
+      {:ok, _create} = CommonAPI.post_chat_message(other_user, user, "sup part 2")
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+      object = Object.normalize(create, fetch: false)
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      assert cm_ref.unread == true
+
+      result =
+        conn
+        |> post("/api/v1/pleroma/chats/#{chat.id}/messages/#{cm_ref.id}/read")
+        |> json_response_and_validate_schema(200)
+
+      assert result["unread"] == false
+
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      assert cm_ref.unread == false
+    end
+  end
+
+  describe "POST /api/v1/pleroma/chats/:id/read" do
+    setup do: oauth_access(["write:chats"])
+
+    test "given a `last_read_id`, it marks everything until then as read", %{
+      conn: conn,
+      user: user
+    } do
+      other_user = insert(:user)
+
+      {:ok, create} = CommonAPI.post_chat_message(other_user, user, "sup")
+      {:ok, _create} = CommonAPI.post_chat_message(other_user, user, "sup part 2")
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+      object = Object.normalize(create, fetch: false)
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      assert cm_ref.unread == true
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/pleroma/chats/#{chat.id}/read", %{"last_read_id" => cm_ref.id})
+        |> json_response_and_validate_schema(200)
+
+      assert result["unread"] == 1
+
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      assert cm_ref.unread == false
+    end
+  end
+
+  describe "POST /api/v1/pleroma/chats/:id/messages" do
+    setup do: oauth_access(["write:chats"])
+
+    test "it posts a message to the chat", %{conn: conn, user: user} do
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> put_req_header("idempotency-key", "123")
+        |> post("/api/v1/pleroma/chats/#{chat.id}/messages", %{"content" => "Hallo!!"})
+        |> json_response_and_validate_schema(200)
+
+      assert result["content"] == "Hallo!!"
+      assert result["chat_id"] == chat.id |> to_string()
+      assert result["idempotency_key"] == "123"
+    end
+
+    test "it fails if there is no content", %{conn: conn, user: user} do
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/pleroma/chats/#{chat.id}/messages")
+        |> json_response_and_validate_schema(400)
+
+      assert %{"error" => "no_content"} == result
+    end
+
+    test "it works with an attachment", %{conn: conn, user: user} do
+      clear_config([Pleroma.Upload, :uploader], Pleroma.Uploaders.Local)
+      clear_config([Pleroma.Uploaders.Local, :uploads], "uploads")
+
+      file = %Plug.Upload{
+        content_type: "image/jpeg",
+        path: Path.absname("test/fixtures/image.jpg"),
+        filename: "an_image.jpg"
+      }
+
+      {:ok, upload} = ActivityPub.upload(file, actor: user.ap_id)
+
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/pleroma/chats/#{chat.id}/messages", %{
+          "media_id" => to_string(upload.id)
+        })
+        |> json_response_and_validate_schema(200)
+
+      assert result["attachment"]
+    end
+
+    test "gets MRF reason when rejected", %{conn: conn, user: user} do
+      clear_config([:mrf_keyword, :reject], ["GNO"])
+      clear_config([:mrf, :policies], [Pleroma.Web.ActivityPub.MRF.KeywordPolicy])
+
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> post("/api/v1/pleroma/chats/#{chat.id}/messages", %{"content" => "GNO/Linux"})
+        |> json_response_and_validate_schema(422)
+
+      assert %{"error" => "[KeywordPolicy] Matches with rejected keyword"} == result
+    end
+  end
+
+  describe "DELETE /api/v1/pleroma/chats/:id/messages/:message_id" do
+    setup do: oauth_access(["write:chats"])
+
+    test "it deletes a message from the chat", %{conn: conn, user: user} do
+      recipient = insert(:user)
+
+      {:ok, message} =
+        CommonAPI.post_chat_message(user, recipient, "Hello darkness my old friend")
+
+      {:ok, other_message} = CommonAPI.post_chat_message(recipient, user, "nico nico ni")
+
+      object = Object.normalize(message, fetch: false)
+
+      chat = Chat.get(user.id, recipient.ap_id)
+
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      # Deleting your own message removes the message and the reference
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> delete("/api/v1/pleroma/chats/#{chat.id}/messages/#{cm_ref.id}")
+        |> json_response_and_validate_schema(200)
+
+      assert result["id"] == cm_ref.id
+      refute MessageReference.get_by_id(cm_ref.id)
+      assert %{data: %{"type" => "Tombstone"}} = Object.get_by_id(object.id)
+
+      # Deleting other people's messages just removes the reference
+      object = Object.normalize(other_message, fetch: false)
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+      result =
+        conn
+        |> put_req_header("content-type", "application/json")
+        |> delete("/api/v1/pleroma/chats/#{chat.id}/messages/#{cm_ref.id}")
+        |> json_response_and_validate_schema(200)
+
+      assert result["id"] == cm_ref.id
+      refute MessageReference.get_by_id(cm_ref.id)
+      assert Object.get_by_id(object.id)
+    end
+  end
+
+  describe "GET /api/v1/pleroma/chats/:id/messages" do
+    setup do: oauth_access(["read:chats"])
+
+    test "it paginates", %{conn: conn, user: user} do
+      recipient = insert(:user)
+
+      Enum.each(1..30, fn _ ->
+        {:ok, _} = CommonAPI.post_chat_message(user, recipient, "hey")
+      end)
+
+      chat = Chat.get(user.id, recipient.ap_id)
+
+      response = get(conn, "/api/v1/pleroma/chats/#{chat.id}/messages")
+      result = json_response_and_validate_schema(response, 200)
+
+      [next, prev] = get_resp_header(response, "link") |> hd() |> String.split(", ")
+      api_endpoint = "/api/v1/pleroma/chats/"
+
+      assert String.match?(
+               next,
+               ~r(#{api_endpoint}.*/messages\?limit=\d+&max_id=.*; rel=\"next\"$)
+             )
+
+      assert String.match?(
+               prev,
+               ~r(#{api_endpoint}.*/messages\?limit=\d+&min_id=.*; rel=\"prev\"$)
+             )
+
+      assert length(result) == 20
+
+      response =
+        get(conn, "/api/v1/pleroma/chats/#{chat.id}/messages?max_id=#{List.last(result)["id"]}")
+
+      result = json_response_and_validate_schema(response, 200)
+      [next, prev] = get_resp_header(response, "link") |> hd() |> String.split(", ")
+
+      assert String.match?(
+               next,
+               ~r(#{api_endpoint}.*/messages\?limit=\d+&max_id=.*; rel=\"next\"$)
+             )
+
+      assert String.match?(
+               prev,
+               ~r(#{api_endpoint}.*/messages\?limit=\d+&max_id=.*&min_id=.*; rel=\"prev\"$)
+             )
+
+      assert length(result) == 10
+    end
+
+    test "it returns the messages for a given chat", %{conn: conn, user: user} do
+      other_user = insert(:user)
+      third_user = insert(:user)
+
+      {:ok, _} = CommonAPI.post_chat_message(user, other_user, "hey")
+      {:ok, _} = CommonAPI.post_chat_message(user, third_user, "hey")
+      {:ok, _} = CommonAPI.post_chat_message(user, other_user, "how are you?")
+      {:ok, _} = CommonAPI.post_chat_message(other_user, user, "fine, how about you?")
+
+      chat = Chat.get(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> get("/api/v1/pleroma/chats/#{chat.id}/messages")
+        |> json_response_and_validate_schema(200)
+
+      result
+      |> Enum.each(fn message ->
+        assert message["chat_id"] == chat.id |> to_string()
+      end)
+
+      assert length(result) == 3
+
+      # Trying to get the chat of a different user
+      other_user_chat = Chat.get(other_user.id, user.ap_id)
+
+      conn
+      |> get("/api/v1/pleroma/chats/#{other_user_chat.id}/messages")
+      |> json_response_and_validate_schema(404)
+    end
+  end
+
+  describe "POST /api/v1/pleroma/chats/by-account-id/:id" do
+    setup do: oauth_access(["write:chats"])
+
+    test "it creates or returns a chat", %{conn: conn} do
+      other_user = insert(:user)
+
+      result =
+        conn
+        |> post("/api/v1/pleroma/chats/by-account-id/#{other_user.id}")
+        |> json_response_and_validate_schema(200)
+
+      assert result["id"]
+    end
+  end
+
+  describe "GET /api/v1/pleroma/chats/:id" do
+    setup do: oauth_access(["read:chats"])
+
+    test "it returns a chat", %{conn: conn, user: user} do
+      other_user = insert(:user)
+
+      {:ok, chat} = Chat.get_or_create(user.id, other_user.ap_id)
+
+      result =
+        conn
+        |> get("/api/v1/pleroma/chats/#{chat.id}")
+        |> json_response_and_validate_schema(200)
+
+      assert result["id"] == to_string(chat.id)
+    end
+  end
+
+  describe "GET /api/v2/pleroma/chats" do
+    setup do: oauth_access(["read:chats"])
+
+    test "it does not return chats with deleted users", %{conn: conn, user: user} do
+      recipient = insert(:user)
+      {:ok, _} = Chat.get_or_create(user.id, recipient.ap_id)
+
+      Pleroma.Repo.delete(recipient)
+      User.invalidate_cache(recipient)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 0
+    end
+
+    test "it does not return chats with users you blocked", %{conn: conn, user: user} do
+      recipient = insert(:user)
+
+      {:ok, _} = Chat.get_or_create(user.id, recipient.ap_id)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 1
+
+      User.block(user, recipient)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 0
+    end
+
+    test "it does not return chats with users you muted", %{conn: conn, user: user} do
+      recipient = insert(:user)
+
+      {:ok, _} = Chat.get_or_create(user.id, recipient.ap_id)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 1
+
+      User.mute(user, recipient)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 0
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats?with_muted=true")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 1
+    end
+
+    test "it paginates chats", %{conn: conn, user: user} do
+      Enum.each(1..30, fn _ ->
+        recipient = insert(:user)
+        {:ok, _} = Chat.get_or_create(user.id, recipient.ap_id)
+      end)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 20
+      last_id = List.last(result)["id"]
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats?max_id=#{last_id}")
+        |> json_response_and_validate_schema(200)
+
+      assert length(result) == 10
+    end
+
+    test "it return a list of chats the current user is participating in, in descending order of updates",
+         %{conn: conn, user: user} do
+      har = insert(:user)
+      jafnhar = insert(:user)
+      tridi = insert(:user)
+
+      {:ok, chat_1} = Chat.get_or_create(user.id, har.ap_id)
+      {:ok, chat_1} = time_travel(chat_1, -3)
+      {:ok, chat_2} = Chat.get_or_create(user.id, jafnhar.ap_id)
+      {:ok, _chat_2} = time_travel(chat_2, -2)
+      {:ok, chat_3} = Chat.get_or_create(user.id, tridi.ap_id)
+      {:ok, chat_3} = time_travel(chat_3, -1)
+
+      # bump the second one
+      {:ok, chat_2} = Chat.bump_or_create(user.id, jafnhar.ap_id)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      ids = Enum.map(result, & &1["id"])
+
+      assert ids == [
+               chat_2.id |> to_string(),
+               chat_3.id |> to_string(),
+               chat_1.id |> to_string()
+             ]
+    end
+
+    test "it is not affected by :restrict_unauthenticated setting (issue #1973)", %{
+      conn: conn,
+      user: user
+    } do
+      clear_config([:restrict_unauthenticated, :profiles, :local], true)
+      clear_config([:restrict_unauthenticated, :profiles, :remote], true)
+
+      user2 = insert(:user)
+      user3 = insert(:user, local: false)
+
+      {:ok, _chat_12} = Chat.get_or_create(user.id, user2.ap_id)
+      {:ok, _chat_13} = Chat.get_or_create(user.id, user3.ap_id)
+
+      result =
+        conn
+        |> get("/api/v2/pleroma/chats")
+        |> json_response_and_validate_schema(200)
+
+      account_ids = Enum.map(result, &get_in(&1, ["account", "id"]))
+      assert Enum.sort(account_ids) == Enum.sort([user2.id, user3.id])
+    end
+  end
+end
diff --git a/test/pleroma/web/pleroma_api/views/chat_message_reference_view_test.exs b/test/pleroma/web/pleroma_api/views/chat_message_reference_view_test.exs
new file mode 100644
index 000000000..6deaa2102
--- /dev/null
+++ b/test/pleroma/web/pleroma_api/views/chat_message_reference_view_test.exs
@@ -0,0 +1,75 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.PleromaAPI.ChatMessageReferenceViewTest do
+  use Pleroma.DataCase
+
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.Object
+  alias Pleroma.Web.ActivityPub.ActivityPub
+  alias Pleroma.Web.CommonAPI
+  alias Pleroma.Web.PleromaAPI.Chat.MessageReferenceView
+
+  import Pleroma.Factory
+
+  test "it displays a chat message" do
+    user = insert(:user)
+    recipient = insert(:user)
+
+    file = %Plug.Upload{
+      content_type: "image/jpeg",
+      path: Path.absname("test/fixtures/image.jpg"),
+      filename: "an_image.jpg"
+    }
+
+    {:ok, upload} = ActivityPub.upload(file, actor: user.ap_id)
+
+    {:ok, activity} =
+      CommonAPI.post_chat_message(user, recipient, "kippis :firefox:", idempotency_key: "123")
+
+    chat = Chat.get(user.id, recipient.ap_id)
+
+    object = Object.normalize(activity, fetch: false)
+
+    cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+    chat_message = MessageReferenceView.render("show.json", chat_message_reference: cm_ref)
+
+    assert chat_message[:id] == cm_ref.id
+    assert chat_message[:content] == "kippis :firefox:"
+    assert chat_message[:account_id] == user.id
+    assert chat_message[:chat_id]
+    assert chat_message[:created_at]
+    assert chat_message[:unread] == false
+    assert match?([%{shortcode: "firefox"}], chat_message[:emojis])
+    assert chat_message[:idempotency_key] == "123"
+
+    clear_config([:rich_media, :enabled], true)
+
+    Tesla.Mock.mock_global(fn
+      %{url: "https://example.com/ogp"} ->
+        %Tesla.Env{status: 200, body: File.read!("test/fixtures/rich_media/ogp.html")}
+    end)
+
+    {:ok, activity} =
+      CommonAPI.post_chat_message(recipient, user, "gkgkgk https://example.com/ogp",
+        media_id: upload.id
+      )
+
+    object = Object.normalize(activity, fetch: false)
+
+    cm_ref = MessageReference.for_chat_and_object(chat, object)
+
+    chat_message_two = MessageReferenceView.render("show.json", chat_message_reference: cm_ref)
+
+    assert chat_message_two[:id] == cm_ref.id
+    assert chat_message_two[:content] == object.data["content"]
+    assert chat_message_two[:account_id] == recipient.id
+    assert chat_message_two[:chat_id] == chat_message[:chat_id]
+    assert chat_message_two[:attachment]
+    assert chat_message_two[:unread] == true
+    assert chat_message_two[:card]
+  end
+end
diff --git a/test/pleroma/web/pleroma_api/views/chat_view_test.exs b/test/pleroma/web/pleroma_api/views/chat_view_test.exs
new file mode 100644
index 000000000..5456c2de0
--- /dev/null
+++ b/test/pleroma/web/pleroma_api/views/chat_view_test.exs
@@ -0,0 +1,49 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.PleromaAPI.ChatViewTest do
+  use Pleroma.DataCase, async: true
+
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
+  alias Pleroma.Object
+  alias Pleroma.Web.CommonAPI
+  alias Pleroma.Web.CommonAPI.Utils
+  alias Pleroma.Web.MastodonAPI.AccountView
+  alias Pleroma.Web.PleromaAPI.Chat.MessageReferenceView
+  alias Pleroma.Web.PleromaAPI.ChatView
+
+  import Pleroma.Factory
+
+  test "it represents a chat" do
+    user = insert(:user)
+    recipient = insert(:user)
+
+    {:ok, chat} = Chat.get_or_create(user.id, recipient.ap_id)
+
+    represented_chat = ChatView.render("show.json", chat: chat)
+
+    assert represented_chat == %{
+             id: "#{chat.id}",
+             account:
+               AccountView.render("show.json", user: recipient, skip_visibility_check: true),
+             unread: 0,
+             last_message: nil,
+             updated_at: Utils.to_masto_date(chat.updated_at)
+           }
+
+    {:ok, chat_message_creation} = CommonAPI.post_chat_message(user, recipient, "hello")
+
+    chat_message = Object.normalize(chat_message_creation, fetch: false)
+
+    {:ok, chat} = Chat.get_or_create(user.id, recipient.ap_id)
+
+    represented_chat = ChatView.render("show.json", chat: chat)
+
+    cm_ref = MessageReference.for_chat_and_object(chat, chat_message)
+
+    assert represented_chat[:last_message] ==
+             MessageReferenceView.render("show.json", chat_message_reference: cm_ref)
+  end
+end
diff --git a/test/pleroma/web/push/impl_test.exs b/test/pleroma/web/push/impl_test.exs
index 326872ccd..aa20b3227 100644
--- a/test/pleroma/web/push/impl_test.exs
+++ b/test/pleroma/web/push/impl_test.exs
@@ -7,8 +7,10 @@ defmodule Pleroma.Web.Push.ImplTest do
 
   import Pleroma.Factory
 
+  alias Pleroma.Notification
   alias Pleroma.Object
   alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.CommonAPI
   alias Pleroma.Web.Push.Impl
   alias Pleroma.Web.Push.Subscription
@@ -229,6 +231,46 @@ defmodule Pleroma.Web.Push.ImplTest do
   end
 
   describe "build_content/3" do
+    test "builds content for chat messages" do
+      user = insert(:user)
+      recipient = insert(:user)
+
+      {:ok, chat} = CommonAPI.post_chat_message(user, recipient, "hey")
+      object = Object.normalize(chat, fetch: false)
+      [notification] = Notification.for_user(recipient)
+
+      res = Impl.build_content(notification, user, object)
+
+      assert res == %{
+               body: "@#{user.nickname}: hey",
+               title: "New Chat Message"
+             }
+    end
+
+    test "builds content for chat messages with no content" do
+      user = insert(:user)
+      recipient = insert(:user)
+
+      file = %Plug.Upload{
+        content_type: "image/jpeg",
+        path: Path.absname("test/fixtures/image.jpg"),
+        filename: "an_image.jpg"
+      }
+
+      {:ok, upload} = ActivityPub.upload(file, actor: user.ap_id)
+
+      {:ok, chat} = CommonAPI.post_chat_message(user, recipient, nil, media_id: upload.id)
+      object = Object.normalize(chat, fetch: false)
+      [notification] = Notification.for_user(recipient)
+
+      res = Impl.build_content(notification, user, object)
+
+      assert res == %{
+               body: "@#{user.nickname}: (Attachment)",
+               title: "New Chat Message"
+             }
+    end
+
     test "hides contents of notifications when option enabled" do
       user = insert(:user, nickname: "Bob")
 
diff --git a/test/pleroma/web/shout_channel_test.exs b/test/pleroma/web/shout_channel_test.exs
new file mode 100644
index 000000000..5c86efe9f
--- /dev/null
+++ b/test/pleroma/web/shout_channel_test.exs
@@ -0,0 +1,41 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ShoutChannelTest do
+  use Pleroma.Web.ChannelCase
+  alias Pleroma.Web.ShoutChannel
+  alias Pleroma.Web.UserSocket
+
+  import Pleroma.Factory
+
+  setup do
+    user = insert(:user)
+
+    {:ok, _, socket} =
+      socket(UserSocket, "", %{user_name: user.nickname})
+      |> subscribe_and_join(ShoutChannel, "chat:public")
+
+    {:ok, socket: socket}
+  end
+
+  test "it broadcasts a message", %{socket: socket} do
+    push(socket, "new_msg", %{"text" => "why is tenshi eating a corndog so cute?"})
+    assert_broadcast("new_msg", %{text: "why is tenshi eating a corndog so cute?"})
+  end
+
+  describe "message lengths" do
+    setup do: clear_config([:shout, :limit])
+
+    test "it ignores messages of length zero", %{socket: socket} do
+      push(socket, "new_msg", %{"text" => ""})
+      refute_broadcast("new_msg", %{text: ""})
+    end
+
+    test "it ignores messages above a certain length", %{socket: socket} do
+      clear_config([:shout, :limit], 2)
+      push(socket, "new_msg", %{"text" => "123"})
+      refute_broadcast("new_msg", %{text: "123"})
+    end
+  end
+end
diff --git a/test/pleroma/web/streamer_test.exs b/test/pleroma/web/streamer_test.exs
index b07c16faa..219d9109e 100644
--- a/test/pleroma/web/streamer_test.exs
+++ b/test/pleroma/web/streamer_test.exs
@@ -7,11 +7,15 @@ defmodule Pleroma.Web.StreamerTest do
 
   import Pleroma.Factory
 
+  alias Pleroma.Chat
+  alias Pleroma.Chat.MessageReference
   alias Pleroma.Conversation.Participation
   alias Pleroma.List
+  alias Pleroma.Object
   alias Pleroma.User
   alias Pleroma.Web.CommonAPI
   alias Pleroma.Web.Streamer
+  alias Pleroma.Web.StreamerView
 
   @moduletag needs_streamer: true, capture_log: true
 
@@ -76,16 +80,20 @@ defmodule Pleroma.Web.StreamerTest do
       expected_user_topic = "user:#{user.id}"
       expected_notification_topic = "user:notification:#{user.id}"
       expected_direct_topic = "direct:#{user.id}"
+      expected_pleroma_chat_topic = "user:pleroma_chat:#{user.id}"
 
       for valid_user_token <- [read_oauth_token, read_statuses_token] do
         assert {:ok, ^expected_user_topic} = Streamer.get_topic("user", user, valid_user_token)
 
         assert {:ok, ^expected_direct_topic} =
                  Streamer.get_topic("direct", user, valid_user_token)
+
+        assert {:ok, ^expected_pleroma_chat_topic} =
+                 Streamer.get_topic("user:pleroma_chat", user, valid_user_token)
       end
 
       for invalid_user_token <- [read_notifications_token, badly_scoped_token],
-          user_topic <- ["user", "direct"] do
+          user_topic <- ["user", "direct", "user:pleroma_chat"] do
         assert {:error, :unauthorized} = Streamer.get_topic(user_topic, user, invalid_user_token)
       end
 
@@ -258,6 +266,66 @@ defmodule Pleroma.Web.StreamerTest do
       refute Streamer.filtered_by_user?(user, notify)
     end
 
+    test "it sends chat messages to the 'user:pleroma_chat' stream", %{
+      user: user,
+      token: oauth_token
+    } do
+      other_user = insert(:user)
+
+      {:ok, create_activity} =
+        CommonAPI.post_chat_message(other_user, user, "hey cirno", idempotency_key: "123")
+
+      object = Object.normalize(create_activity, fetch: false)
+      chat = Chat.get(user.id, other_user.ap_id)
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+      cm_ref = %{cm_ref | chat: chat, object: object}
+
+      Streamer.get_topic_and_add_socket("user:pleroma_chat", user, oauth_token)
+      Streamer.stream("user:pleroma_chat", {user, cm_ref})
+
+      text = StreamerView.render("chat_update.json", %{chat_message_reference: cm_ref})
+
+      assert text =~ "hey cirno"
+      assert_receive {:text, ^text}
+    end
+
+    test "it sends chat messages to the 'user' stream", %{user: user, token: oauth_token} do
+      other_user = insert(:user)
+
+      {:ok, create_activity} = CommonAPI.post_chat_message(other_user, user, "hey cirno")
+      object = Object.normalize(create_activity, fetch: false)
+      chat = Chat.get(user.id, other_user.ap_id)
+      cm_ref = MessageReference.for_chat_and_object(chat, object)
+      cm_ref = %{cm_ref | chat: chat, object: object}
+
+      Streamer.get_topic_and_add_socket("user", user, oauth_token)
+      Streamer.stream("user", {user, cm_ref})
+
+      text = StreamerView.render("chat_update.json", %{chat_message_reference: cm_ref})
+
+      assert text =~ "hey cirno"
+      assert_receive {:text, ^text}
+    end
+
+    test "it sends chat message notifications to the 'user:notification' stream", %{
+      user: user,
+      token: oauth_token
+    } do
+      other_user = insert(:user)
+
+      {:ok, create_activity} = CommonAPI.post_chat_message(other_user, user, "hey")
+
+      notify =
+        Repo.get_by(Pleroma.Notification, user_id: user.id, activity_id: create_activity.id)
+        |> Repo.preload(:activity)
+
+      Streamer.get_topic_and_add_socket("user:notification", user, oauth_token)
+      Streamer.stream("user:notification", notify)
+
+      assert_receive {:render_with_user, _, _, ^notify}
+      refute Streamer.filtered_by_user?(user, notify)
+    end
+
     test "it doesn't send notify to the 'user:notification' stream when a user is blocked", %{
       user: user,
       token: oauth_token