---
title: "Send a message to an existing Microsoft Teams chat as the calling member"
method: POST
path: "/v1/capabilities/microsoft-365/teams-chats/{chatId}/messages"
tags: ["Capability Sources"]
---

# Send a message to an existing Microsoft Teams chat as the calling member

`POST /v1/capabilities/microsoft-365/teams-chats/{chatId}/messages`

## Request

- Base URL: `https://api.openworklabs.com`
- URL: `https://api.openworklabs.com/v1/capabilities/microsoft-365/teams-chats/{chatId}/messages`
- Auth: one of:
  - API key in header `x-api-key`
  - HTTP bearer

Sends one message to an existing Teams chat. The operation cannot create a new chat.

## Path parameters

- `chatId` string, required

## Request body

- Microsoft365TeamsMessageBody
  - `content` string, required

## Response `200`

Teams chat message sent.

- Microsoft365TeamsMessageResponse
  - `ok` true, required
  - `message` Microsoft365TeamsMessage, required
    - `id` string, required
    - `createdDateTime` string, required
    - `content` string, required
    - `from` Microsoft365EmailAddress, required
      - `name` string, required
      - `address` string, required
    - `webUrl` string, required

## Other responses

- `401`: The caller must be signed in.
- `409`: The calling member has not connected their Microsoft account or is missing permission.
- `502`: Microsoft Graph rejected the request.

## Changes

- **2026-09-11** `bb8ff73e4ad3`: 2 info
  - the endpoint scheme security `bearerAuth` was added to the API
  - the endpoint scheme security `denApiKey` was added to the API
- **2026-09-10** `7d79c843d137`: 2 info
  - added the optional property `outcome` to the response with the `502` status
  - added the optional property `retryable` to the response with the `502` status

[Operation history](https://skmtc.dev/openworklabs/apis/den-api/changes/v1/capabilities/microsoft-365/teams-chats/:chatId/messages/post.md)

---

[API](https://skmtc.dev/openworklabs/apis/den-api.md) · [All operations](https://skmtc.dev/openworklabs/apis/den-api/llms.txt) · [OpenAPI document](https://skmtc.dev/openworklabs/apis/den-api/revisions/e6eb4e5ce8a3?raw)