matrix-spec-proposals/api/client-server/third_party_membership.yaml

swagger: '2.0'
info:
  title: "Matrix Client-Server Room Membership API for third party identifiers"
  version: "1.0.0"
host: localhost:8008
schemes:
  - https
  - http
basePath: /_matrix/client/%CLIENT_MAJOR_VERSION%
consumes:
  - application/json
produces:
  - application/json
securityDefinitions:
  $ref: definitions/security.yaml
paths:
  "/rooms/{roomId}/invite":
    post:
      summary: Invite a user to participate in a particular room.
      description: |-
        .. _invite-by-third-party-id-endpoint:

        *Note that there are two forms of this API, which are documented separately.
        This version of the API does not require that the inviter know the Matrix
        identifier of the invitee, and instead relies on third party identifiers.
        The homeserver uses an identity server to perform the mapping from
        third party identifier to a Matrix identifier. The other is documented in the*
        `joining rooms section`_.

        This API invites a user to participate in a particular room.
        They do not start participating in the room until they actually join the
        room.

        Only users currently in a particular room can invite other users to
        join that room.

        If the identity server did know the Matrix user identifier for the
        third party identifier, the homeserver will append a ``m.room.member``
        event to the room.

        If the identity server does not know a Matrix user identifier for the
        passed third party identifier, the homeserver will issue an invitation
        which can be accepted upon providing proof of ownership of the third
        party identifier. This is achieved by the identity server generating a
        token, which it gives to the inviting homeserver. The homeserver will
        add an ``m.room.third_party_invite`` event into the graph for the room,
        containing that token.

        When the invitee binds the invited third party identifier to a Matrix
        user ID, the identity server will give the user a list of pending
        invitations, each containing:

        - The room ID to which they were invited

        - The token given to the homeserver

        - A signature of the token, signed with the identity server's private key

        - The matrix user ID who invited them to the room

        If a token is requested from the identity server, the homeserver will
        append a ``m.room.third_party_invite`` event to the room.

        .. _joining rooms section: `invite-by-user-id-endpoint`_
      security:
        - accessToken: []
      parameters:
        - in: path
          type: string
          name: roomId
          description: The room identifier (not alias) to which to invite the user.
          required: true
          x-example: "!d41d8cd:matrix.org"
        - in: body
          name: body
          required: true
          schema:
            type: object
            example: |-
              {
                "id_server": "matrix.org",
                "medium": "email",
                "address": "cheeky@monkey.com"
              }
            properties:
              id_server:
                type: string
                description: The hostname+port of the identity server which should be used for third party identifier lookups.
              medium:
                type: string
                # TODO: Link to identity service spec when it eixsts
                description: The kind of address being passed in the address field, for example ``email``.
              address:
                type: string
                description: The invitee's third party identifier.
            required: ["id_server", "medium", "address"]
      responses:
        200:
          description: The user has been invited to join the room.
          examples:
            application/json: |-
              {}
          schema:
            type: object
        403:
          description: |-
            You do not have permission to invite the user to the room. A meaningful ``errcode`` and description error text will be returned. Example reasons for rejections are:

            - The invitee has been banned from the room.
            - The invitee is already a member of the room.
            - The inviter is not currently in the room.
            - The inviter's power level is insufficient to invite users to the room.
          examples:
            application/json: |-
              {"errcode": "M_FORBIDDEN", "error": "@cheeky_monkey:matrix.org is banned from the room"}
        429:
          description: This request was rate-limited.
          schema:
            "$ref": "definitions/error.yaml"
      tags:
        - Room membership