nodebb/public/openapi/write/groups/slug/membership/uid.yaml

put:
  tags:
    - groups
  summary: join a group
  description: This operation joins an existing group, or causes another user to join a group. If the group is private and you are not an administrator, this method will cause that user to request membership, instead. For user _invitations_, you'll want to call `PUT /groups/{slug}/invites/{uid}`.
  parameters:
    - in: path
      name: slug
      schema:
        type: string
      required: true
      description: slug of the group you would like to join
      example: my-group
  responses:
    '200':
      description: group successfully joined, or membership requested
      content:
        application/json:
          schema:
            type: object
            properties:
              status:
                $ref: ../../../../components/schemas/Status.yaml#/Status
              response:
                type: object
                properties: {}