openapi: 3.0.3
info:
  title: SignNow REST Authentication API
  description: The SignNow REST API enables developers to embed legally binding e-signature workflows into any application. It supports document upload, template-based signing workflows, signature invitations, bulk signing, user management, and webhook notifications.
  version: '2.0'
  contact:
    name: SignNow API Support
    email: api@signnow.com
    url: https://docs.signnow.com
  termsOfService: https://www.signnow.com/terms-of-service
  license:
    name: MIT
    url: https://github.com/signnow/OpenAPI-Specification/blob/master/LICENSE
servers:
- url: https://api.signnow.com
  description: Production
- url: https://api-eval.signnow.com
  description: Sandbox
security:
- BearerAuth: []
tags:
- name: Authentication
  description: OAuth2 token management
paths:
  /oauth2/token:
    post:
      operationId: createOAuthToken
      summary: Create OAuth Token
      description: Generate an OAuth 2.0 access token using client credentials or password grant type.
      tags:
      - Authentication
      security: []
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              required:
              - grant_type
              - client_id
              - client_secret
              properties:
                grant_type:
                  type: string
                  enum:
                  - password
                  - authorization_code
                  - refresh_token
                  description: OAuth grant type
                client_id:
                  type: string
                  description: Application client ID
                client_secret:
                  type: string
                  description: Application client secret
                username:
                  type: string
                  description: User email (for password grant)
                password:
                  type: string
                  description: User password (for password grant)
                code:
                  type: string
                  description: Authorization code (for authorization_code grant)
                refresh_token:
                  type: string
                  description: Refresh token (for refresh_token grant)
      responses:
        '200':
          description: Access token generated
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/OAuthToken'
        '400':
          description: Invalid request
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    OAuthToken:
      type: object
      properties:
        access_token:
          type: string
          description: Bearer access token
        token_type:
          type: string
          example: bearer
        expires_in:
          type: integer
          description: Token expiry in seconds
        refresh_token:
          type: string
          description: Token for refreshing access
        scope:
          type: string
          description: Token scope
    Error:
      type: object
      properties:
        errors:
          type: array
          items:
            type: object
            properties:
              code:
                type: integer
              message:
                type: string
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      description: OAuth 2.0 Bearer token. Obtain via POST /oauth2/token.
externalDocs:
  description: SignNow API Documentation
  url: https://docs.signnow.com/docs/signnow/welcome