openapi: 3.1.0
info:
  title: WeChat Mini Program Server API (subset) Access Token Login API
  description: 'Subset OpenAPI description for the WeChat (Weixin) Mini Programs server-side

    API hosted at `api.weixin.qq.com`. Covers the foundational endpoints needed

    to bootstrap a Mini Program backend: exchanging a temporary login code for

    a session via `auth.code2Session`, minting an application access token via

    `auth.getAccessToken`, and retrieving a paid-only UnionID via

    `auth.getPaidUnionId`.


    Authentication for these foundational endpoints is keyed on the Mini

    Program''s AppID and AppSecret, passed as query parameters. Subsequent

    business APIs (template messages, content moderation, analytics, QR codes,

    logistics, etc.) require the `access_token` obtained from

    `auth.getAccessToken`.

    '
  version: 1.0.0
  contact:
    name: WeChat Developer Community
    url: https://developers.weixin.qq.com/community/
  license:
    name: Proprietary
servers:
- url: https://api.weixin.qq.com
  description: WeChat production API
tags:
- name: Login
  description: Mini Program login and session exchange.
paths:
  /sns/jscode2session:
    get:
      tags:
      - Login
      summary: auth.code2Session
      description: 'Exchange a temporary login `code` returned by `wx.login()` in the Mini

        Program client for a stable `openid` and `session_key`. The

        `session_key` is used to decrypt encrypted user data delivered by other

        Mini Program APIs.

        '
      operationId: code2Session
      parameters:
      - in: query
        name: appid
        required: true
        schema:
          type: string
        description: Mini Program AppID.
      - in: query
        name: secret
        required: true
        schema:
          type: string
        description: Mini Program AppSecret.
      - in: query
        name: js_code
        required: true
        schema:
          type: string
        description: Temporary login credential `code` from `wx.login()`.
      - in: query
        name: grant_type
        required: true
        schema:
          type: string
          enum:
          - authorization_code
        description: Must be `authorization_code`.
      responses:
        '200':
          description: Session exchange result.
          content:
            application/json:
              schema:
                oneOf:
                - type: object
                  properties:
                    openid:
                      type: string
                      description: Mini Program-scoped user identifier.
                    session_key:
                      type: string
                      description: Session key used to decrypt encrypted payloads.
                    unionid:
                      type: string
                      description: WeChat Open Platform-wide UnionID (when applicable).
                - $ref: '#/components/schemas/WeChatError'
components:
  schemas:
    WeChatError:
      type: object
      description: Standard WeChat API error envelope.
      properties:
        errcode:
          type: integer
          description: Numeric WeChat error code; `0` indicates success.
        errmsg:
          type: string
          description: Human-readable error message.
externalDocs:
  description: WeChat Mini Program Server API
  url: https://developers.weixin.qq.com/miniprogram/en/dev/api-backend/