openapi: 3.0.3
info:
  title: Quaderno Authentication Payments API
  description: 'The Quaderno API is a REST API for tax compliance, invoicing, and sales tax / VAT automation. It exposes resources with predictable, account-scoped URLs and uses standard HTTP features - HTTP Basic Authentication, standard methods, and response codes. All requests and responses are JSON, and every endpoint path ends in `.json` to indicate JSON serialization.

    The base URL is account-scoped: `https://ACCOUNT_NAME.quadernoapp.com/api`, where `ACCOUNT_NAME` is your Quaderno account subdomain. Authenticate with your private API key as the HTTP Basic Auth username (any value for the password). Sandbox testing is available on a separate sandbox host.

    Core resources include Contacts, Items, Invoices, Credits, Estimates, Expenses, Recurring documents, Payments, Transactions, Checkout Sessions, Webhooks, and the tax engine (tax rate calculation, tax jurisdictions, tax codes, and tax ID validation). Endpoint paths and the account-scoped base URL are confirmed against Quaderno''s public developer documentation and the official quaderno-ruby SDK; request and response bodies are modeled and should be verified against the live API reference.'
  version: '1.0'
  contact:
    name: Quaderno
    url: https://developers.quaderno.io
  license:
    name: Proprietary
    url: https://quaderno.io/terms/
servers:
- url: https://{account}.quadernoapp.com/api
  description: Production (account-scoped)
  variables:
    account:
      default: ACCOUNT_NAME
      description: Your Quaderno account subdomain.
security:
- basicAuth: []
tags:
- name: Payments
  description: Payments recorded against invoices, credits, and expenses.
paths:
  /invoices/{id}/payments.json:
    parameters:
    - $ref: '#/components/parameters/Id'
    post:
      operationId: createInvoicePayment
      tags:
      - Payments
      summary: Add a payment to an invoice
      description: Records a payment against the invoice.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/PaymentInput'
      responses:
        '201':
          description: The created payment.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Payment'
        '422':
          $ref: '#/components/responses/ValidationError'
  /invoices/{id}/payments/{payment_id}.json:
    parameters:
    - $ref: '#/components/parameters/Id'
    - name: payment_id
      in: path
      required: true
      description: The ID of the payment.
      schema:
        type: string
    delete:
      operationId: deleteInvoicePayment
      tags:
      - Payments
      summary: Remove a payment from an invoice
      responses:
        '204':
          description: The payment was removed.
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    ValidationError:
      description: The request payload failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  parameters:
    Id:
      name: id
      in: path
      required: true
      description: The unique ID of the resource.
      schema:
        type: string
  schemas:
    Payment:
      allOf:
      - $ref: '#/components/schemas/PaymentInput'
      - type: object
        properties:
          id:
            type: string
    PaymentInput:
      type: object
      required:
      - amount
      properties:
        amount:
          type: number
        payment_method:
          type: string
          enum:
          - credit_card
          - cash
          - wire_transfer
          - direct_debit
          - check
          - paypal
          - other
        date:
          type: string
    Error:
      type: object
      properties:
        error:
          type: string
        errors:
          type: object
          additionalProperties: true
  securitySchemes:
    basicAuth:
      type: http
      scheme: basic
      description: HTTP Basic Authentication. Use your private API key as the username; the password can be any value. API keys are managed in the Quaderno account settings.