Lichess Messaging API

openapi: 3.1.0
info:
  version: 2.0.144
  title: Lichess.org API reference Account Messaging API
  contact:
    name: Lichess.org API
    url: https://lichess.org/api
    email: contact@lichess.org
  x-logo:
    url: https://lichess1.org/assets/logo/lichess-pad12.svg
  license:
    name: AGPL-3.0-or-later
    url: https://www.gnu.org/licenses/agpl-3.0.txt
  description: '# Introduction

    Welcome to the reference for the Lichess API! Lichess is free/libre,

    open-source chess server powered by volunteers and donations.

    - Get help in the [Lichess Discord channel](https://discord.gg/lichess)

    - API demo app with OAuth2 login and gameplay: [source](https://github.com/lichess-org/api-demo) / [demo](https://lichess-org.github.io/api-demo/)

    - API UI app with OAuth2 login and endpoint forms: [source](https://github.com/lichess-org/api-ui) / [website](https://lichess.org/api/ui)

    - [Contribute to this documentation on Github](https://github.com/lichess-org/api)

    - Check out [Lichess widgets to embed in your website](https://lichess.org/developers)

    - [Download all Lichess rated games](https://database.lichess.org/)

    - [Download all Lichess puzzles with themes, ratings and votes](https://database.lichess.org/#puzzles)

    - [Download all evaluated positions](https://database.lichess.org/#evals)


    ## Endpoint

    All requests go to `https://lichess.org` (unless otherwise specified).


    ## Clients

    - [Python general API](https://github.com/lichess-org/berserk)

    - [MicroPython general API](https://github.com/mkomon/uberserk)

    - [Python general API - async](https://pypi.org/project/async-lichess-sdk)

    - [Python Lichess Bot](https://github.com/lichess-bot-devs/lichess-bot)

    - [Python Board API for Certabo](https://github.com/haklein/certabo-lichess)

    - [Java general API](https://github.com/tors42/chariot)

    - [JavaScript & TypeScript general API](https://github.com/devjiwonchoi/equine)

    - [LichessNET - C# API Wrapper](https://github.com/Rabergsel/LichessNET)

    - [.NET general API](https://github.com/Dblike/LichessSharp)


    ## Rate limiting

    All requests are rate limited using various strategies,

    to ensure the API remains responsive for everyone.

    Only make one request at a time.

    If you receive an HTTP response with a [429 status](https://en.wikipedia.org/wiki/List_of_HTTP_status_codes#429),

    you have exceded one of the rate limits.

    In most cases, waiting one minute before retrying will be sufficient, but some limits may require longer.

    Reduce your request frequency before retrying.


    ## Streaming with ND-JSON

    Some API endpoints stream their responses as [Newline Delimited JSON a.k.a. **nd-json**](https://github.com/ndjson/ndjson-spec), with one JSON object per line.


    Here''s a [JavaScript utility function](https://gist.github.com/ornicar/a097406810939cf7be1df8ea30e94f3e) to help reading NDJSON streamed responses.


    ## Authentication

    ### Which authentication method is right for me?

    [Read about the Lichess API authentication methods and code examples](https://github.com/lichess-org/api/blob/master/example/README.md)


    ### Personal Access Token

    Personal API access tokens allow you to quickly interact with Lichess API without going through an OAuth flow.

    - [Generate a personal access token](https://lichess.org/account/oauth/token)

    - `curl https://lichess.org/api/account -H "Authorization: Bearer {token}"`

    - [NodeJS example](https://github.com/lichess-org/api/tree/master/example/oauth-personal-token)


    ### Token Security

    - Keep your tokens secret. Do not share them in public repositories or public forums.

    - Your tokens can be used to make your account perform arbitrary actions (within the limits of the tokens'' scope). You remain responsible for all activities on your account.

    - Do not hardcode tokens in your application''s code. Use environment variables or a secure storage and ensure they are not shipped/exposed to users. Be especially careful that they are not included in frontend bundles or apps that are shipped to users.

    - If you suspect a token has been compromised, revoke it immediately.


    To see your active tokens or revoke them, see [your Personal API access tokens](https://lichess.org/account/oauth/token).


    ### Authorization Code Flow with PKCE

    The authorization code flow with PKCE allows your users to **login with Lichess**.

    Lichess supports unregistered and public clients (no client authentication, choose any unique client id).

    The only accepted code challenge method is `S256`.

    Access tokens are long-lived (expect one year), unless they are revoked.

    Refresh tokens are not supported.


    See the [documentation for the OAuth endpoints](#tag/OAuth) or

    the [PKCE RFC](https://datatracker.ietf.org/doc/html/rfc7636#section-4) for a precise protocol description.


    - [Demo app](https://lichess-org.github.io/api-demo/)

    - [Minimal client-side example](https://github.com/lichess-org/api/tree/master/example/oauth-app)

    - [Flask/Python example](https://github.com/lakinwecker/lichess-oauth-flask)

    - [Java example](https://github.com/tors42/lichess-oauth-pkce-app)

    - [NodeJS Passport strategy to login with Lichess OAuth2](https://www.npmjs.com/package/passport-lichess)


    #### Real life examples

    - [PyChess](https://github.com/gbtami/pychess-variants) ([source code](https://github.com/gbtami/pychess-variants))

    - [Lichess4545](https://www.lichess4545.com/) ([source code](https://github.com/cyanfish/heltour))

    - [English Chess Federation](https://ecf.octoknight.com/)

    - [Rotherham Online Chess](https://rotherhamonlinechess.azurewebsites.net/tournaments)


    ### Token format

    Access tokens and authorization codes match `^[A-Za-z0-9_]+$`.

    The length of tokens can be increased without notice. Make sure your application can handle at least 512 characters.

    By convention tokens have a recognizable prefix, but do not rely on this.

    '
servers:
- url: https://lichess.org
- url: https://lichess.dev
- url: http://localhost:{port}
  variables:
    port:
      default: '8080'
- url: http://l.org
tags:
- name: Messaging
  description: 'Private messages with other players.

    <https://lichess.org/inbox>

    '
paths:
  /inbox/{username}:
    post:
      operationId: inboxUsername
      summary: Send a private message
      description: 'Send a private message to another player.

        '
      tags:
      - Messaging
      security:
      - OAuth2:
        - msg:write
      parameters:
      - in: path
        name: username
        schema:
          type: string
          example: someplayer
        required: true
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              properties:
                text:
                  type: string
                  example: Thank you for the game!
              required:
              - text
      responses:
        '200':
          description: The private message has been successfully sent.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Ok'
        '400':
          description: The sending of the private message has failed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    Ok:
      properties:
        ok:
          type: boolean
      required:
      - ok
    Error:
      type: object
      properties:
        error:
          type: string
          description: The cause of the error.
      required:
      - error
      example:
        error: This request is invalid because [...]
  securitySchemes:
    OAuth2:
      type: oauth2
      description: 'Read [the introduction for how to make authenticated requests](#description/authentication).

        '
      flows:
        authorizationCode:
          authorizationUrl: https://lichess.org/oauth
          tokenUrl: https://lichess.org/api/token
          scopes:
            preference:read: Read your preferences
            preference:write: Write your preferences
            email:read: Read your email address
            engine:read: Read your external engines
            engine:write: Create, update, delete your external engines
            challenge:read: Read incoming challenges
            challenge:write: Create, accept, decline challenges
            challenge:bulk: Create, delete, query bulk pairings
            study:read: Read private studies and broadcasts
            study:write: Create, update, delete studies and broadcasts
            tournament:write: Create tournaments
            racer:write: Create and join puzzle races
            puzzle:read: Read puzzle activity
            puzzle:write: Write puzzle activity
            team:read: Read private team information
            team:write: Join, leave teams
            team:lead: Manage teams (kick members, send PMs)
            follow:read: Read followed players
            follow:write: Follow and unfollow other players
            msg:write: Send private messages to other players
            board:play: Play with the Board API
            bot:play: Play with the Bot API. Only for [Bot accounts](#tag/bot/POST/api/bot/account/upgrade)
            web:mod: Use moderator tools (within the bounds of your permissions)