---
title: "Create or start a chat"
method: POST
path: "/v1/chats"
tags: ["Chats"]
---

# Create or start a chat

`POST /v1/chats`

Create a single/group chat (mode='create') or start a direct chat from merged user data (mode='start').

## Request body

- CreateChatInput
  - `accountID` string, required — Account to create or start the chat on.
  - `mode` 'create' | 'start' — Operation mode. Defaults to 'create' when omitted.
  - `type` 'single' | 'group' — Required when mode='create'. 'single' requires exactly one participantID; 'group' supports multiple participants and optional title.
  - `participantIDs` string[] — Required when mode='create'. User IDs to include in the new chat.
  - `title` string — Optional title for group chats when mode='create'; ignored for single chats on most platforms.
  - `user` object — Required when mode='start'. Merged user-like contact payload used to resolve the best identifier.
    - `id` string — Known user ID when available.
    - `username` string — Username/handle candidate.
    - `phoneNumber` string — Phone number candidate (E.164 preferred).
    - `email` string — Email candidate.
    - `fullName` string — Display name hint used for ranking only.
  - `messageText` string — Optional first message content if the platform requires it to create the chat.
  - `allowInvite` boolean — Whether invite-based DM creation is allowed when required by the platform. Used for mode='start'.

## Response `200`

Request executed successfully

- CreateChatOutput
  - `chatID` string, required — Newly created chat ID.
  - `status` 'existing' | 'created' — Only returned in start mode. 'existing' means an existing chat was reused; 'created' means a new chat was created.

## Other responses

- `400` — Invalid request parameters
- `401` — Access token is missing or invalid
- `403` — Access token does not have the required scope
- `404` — Resource not found
- `422` — Unprocessable entity - validation error
- `429` — Too many requests - rate limit exceeded
- `500` — Internal server error

## Changes

- **2026-02-20** `4acef56b00be` — 14 info
  - added `subschema #1, subschema #2, subschema #3` to the `details` response property `anyOf` list for the response status `400`
  - added `subschema #1, subschema #2, subschema #3` to the `details` response property `anyOf` list for the response status `401`
  - added `subschema #1, subschema #2, subschema #3` to the `details` response property `anyOf` list for the response status `403`
  - added `subschema #1, subschema #2, subschema #3` to the `details` response property `anyOf` list for the response status `404`
  - …10 more
- **2026-02-20** `1b8324f05cd3` — 3 breaking, 7 info
  - added the new required request property `accountID`
  - removed `subschema #1, subschema #2` from the request body `anyOf` list
  - the request's body type/format changed from ``/`` to `object`/``
  - added the new optional request property `allowInvite`
  - …6 more
- **2026-02-13** `3f6555bfea11` — 1 breaking, 5 warning, 2 info
  - the request's body type/format changed from `object`/`` to ``/``
  - removed the request property `accountID`
  - removed the request property `messageText`
  - removed the request property `participantIDs`
  - …4 more

[Change history](https://skmtc.dev/beeper/apis/beeper-desktop-api/changes/v1/chats/post.md)

---

[API](https://skmtc.dev/beeper/apis/beeper-desktop-api.md) · [All operations](https://skmtc.dev/beeper/apis/beeper-desktop-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/beeper/beeper-desktop-api/revisions/5a8ac7b545c4/schema)