#Task chat

GET /v1/tasks/:taskId/chat/messages

Reads the task's chat feed — newest messages first. Every task in Bitrix24 has a group chat; this endpoint resolves the chat from the task ID itself, so you never need to know the chat id. A typical scenario is pulling the final messages of a task (e.g. "deployed in im 24.500.0" to extract a release version).

Bitrix24 API: im.v2.Chat.Message.tail (on older portals — im.dialog.messages.get) Scope: task (the key also needs the im B24 scope — see below)

#Query parameters

Parameter Type Req. Description
limit number Messages per page, 1..200, default 50
lastId number Cursor: return messages older than this id. For the next page pass the minimal id of the current one

#Example

Terminal 
curl "https://vibecode.bitrix24.com/v1/tasks/53/chat/messages?limit=50" \
  -H "X-Api-Key: YOUR_API_KEY"

Response:

JSON 
{
  "success": true,
  "data": {
    "messages": [
      {
        "id": 9123,
        "authorId": 20294,
        "text": "deployed in im 24.500.0",
        "createdAt": "2026-06-10T14:51:00+02:00",
        "isSystem": false
      }
    ],
    "hasNextPage": true
  }
}

#Message fields

Field Description
id Message ID — use the minimal one from the page as lastId for the next page
authorId Author (0 for system messages)
text Text with normalized BB-codes
createdAt Creation date, ISO 8601
isSystem System message ("task created", "deadline changed", …) — filter on this flag when you only need human replies

#What to know before you start

  1. The im B24 scope is required. The endpoint reads the chat through Bitrix24 im.* methods — the key's webhook/OAuth grant must include the im scope in addition to task, otherwise the portal returns insufficient_scope.
  2. Access follows chat membership. Bitrix24 returns messages only when the key's B24 user is a member of the task chat (creator, assignee, watcher) or a portal administrator.
  3. Messages come newest-first. The first element is the most recent message. Cursor pagination via lastId goes back through history.
  4. 404 when there is no chat yet. Bitrix24 creates the task chat lazily — a task with no chat messages may have no chat at all (TASK_CHAT_NOT_FOUND).
  5. Older portals. On portals without the modern im.v2 surface the API transparently switches to the legacy method: the page is capped at 50 messages there and hasNextPage is derived from page fullness.
  6. Comments vs chat. `GET /v1/tasks/:taskId/comments` returns only human comments; this endpoint returns the raw chat feed in full, including system messages.

#Errors

HTTP Code Cause
400 INVALID_PARAMS Non-numeric taskId, non-numeric/non-positive limit or lastId (limit above 200 is not an error — it is silently capped to 200)
403 SCOPE_DENIED The key lacks the task scope
404 TASK_CHAT_NOT_FOUND The task has no chat (or the task does not exist)
422 BITRIX_ERROR Bitrix24 error: insufficient_scope (no im), ACCESS_ERROR (not a chat member)

#See also

  • Tasks — the parent entity
  • Task comments — filtered human comments + posting
  • Scrum — epics and scrum placement of tasks