Fintecture OAuth and Tokens API

openapi: 3.1.0
info:
  title: Fintecture OAuth and Tokens API
  description: >
    Authentication endpoints. The /v1/access-token endpoint issues access tokens
    via the authorization_code grant (used for AIS code exchange) and the
    client_credentials grant (used for PIS, Customers, E-Mandates, and OAC).
    Access tokens are valid for 1 hour and can be refreshed via
    /v1/refresh-token.
  version: "v1"
  contact:
    name: Fintecture Support
    url: https://fintecture.com/contact

servers:
  - url: https://api.fintecture.com
    description: Production
  - url: https://api-sandbox.fintecture.com
    description: Sandbox

tags:
  - name: OAuth
    description: Access and refresh tokens

paths:
  /oauth/accesstoken:
    post:
      summary: Create Access Token
      description: >
        The access token endpoint enables the TPP to authenticate to the Fintecture
        Authentication Server. Two grant types are supported — `authorization_code`
        for AIS, and `client_credentials` for PIS, Customers, E-Mandates, and the
        beta OAC (Organisation Access Credentials) scopes.
      operationId: createAccessToken
      tags: [OAuth]
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              required: [grant_type]
              properties:
                grant_type:
                  type: string
                  enum: [authorization_code, client_credentials]
                code: { type: string }
                redirect_uri: { type: string, format: uri }
                scope:
                  type: string
                  description: One of PIS, AIS, customer, e-mandate, OAC.
                client_id: { type: string }
                client_secret: { type: string }
      responses:
        '200':
          description: Token issued
          content:
            application/json:
              schema: { $ref: '#/components/schemas/AccessToken' }

  /oauth/refreshtoken:
    post:
      summary: Create Refresh Token
      description: Generates a new access_token and invalidates the previous one.
      operationId: createRefreshToken
      tags: [OAuth]
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              required: [grant_type, refresh_token]
              properties:
                grant_type:
                  type: string
                  enum: [refresh_token]
                refresh_token: { type: string }
                client_id: { type: string }
                client_secret: { type: string }
      responses:
        '200':
          description: New token issued
          content:
            application/json:
              schema: { $ref: '#/components/schemas/AccessToken' }

components:
  schemas:
    AccessToken:
      type: object
      properties:
        access_token: { type: string }
        token_type:
          type: string
          enum: [Bearer]
        expires_in:
          type: integer
          description: Lifetime in seconds (3600 by default).
        refresh_token: { type: string }
        scope: { type: string }