Sequence Invoices API

openapi: 3.2.0
info:
  title: Sequence Invoices API
  description: The Sequence API lets you programmatically manage usage-based billing, pricing, and revenue orchestration - customers, usage events and usage metrics, billing schedules, invoices and credit notes, products and prices, and quotes.
  version: '2024-07-30'
  contact:
    name: Sequence
    url: https://www.sequencehq.com
  x-grounding:
    confirmed:
    - GET /customers
    - POST /api/usage-events
    - GET /billing-schedules
    - GET /invoices
    - GET /products
    modeledNote: Operations not in the confirmed list are documented by name in Sequence's reference index; their schemas and some paths are modeled and flagged with x-modeled.
    source: https://docs.sequencehq.com
    reviewer: API Evangelist
    reviewed: '2026-07-12'
servers:
- url: https://eu.sequencehq.com
  description: Production (EU)
- url: https://sandbox.sequencehq.com
  description: Sandbox
security:
- basicAuth: []
tags:
- name: Invoices
  description: Invoice and credit note lifecycle.
paths:
  /invoices:
    get:
      operationId: listInvoices
      tags:
      - Invoices
      summary: List invoices
      description: Lists invoices. Confirmed against the live Sequence API reference (host and path). Response schema modeled.
      responses:
        '200':
          description: A page of invoices.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Invoice'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      operationId: createInvoice
      tags:
      - Invoices
      summary: Create an invoice
      description: Creates a draft invoice. Schema modeled.
      x-modeled: true
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Invoice'
      responses:
        '200':
          description: The created invoice.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Invoice'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /invoices/{id}:
    parameters:
    - $ref: '#/components/parameters/GenericId'
    get:
      operationId: getInvoice
      tags:
      - Invoices
      summary: Get an invoice
      description: Retrieves an invoice by ID. Schema modeled.
      x-modeled: true
      responses:
        '200':
          description: The requested invoice.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Invoice'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /invoices/{id}/finalize:
    parameters:
    - $ref: '#/components/parameters/GenericId'
    post:
      operationId: finalizeInvoice
      tags:
      - Invoices
      summary: Finalize an invoice
      description: Finalizes a draft invoice, moving it out of draft so it can be sent. Path and schema modeled from the documented "Finalize invoice" operation.
      x-modeled: true
      responses:
        '200':
          description: The finalized invoice.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Invoice'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Unauthorized:
      description: Missing or invalid Basic auth credentials.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    ValidationError:
      description: The request payload failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  parameters:
    GenericId:
      name: id
      in: path
      required: true
      description: The resource ID.
      schema:
        type: string
  schemas:
    Error:
      type: object
      description: Error envelope (modeled).
      x-modeled: true
      properties:
        error:
          type: object
          properties:
            code:
              type: string
            message:
              type: string
            details:
              type: object
              additionalProperties: true
    Invoice:
      type: object
      description: Invoice (modeled).
      x-modeled: true
      properties:
        id:
          type: string
        customerId:
          type: string
        status:
          type: string
          description: For example DRAFT, FINALIZED, SENT, PAID, or VOID.
        currency:
          type: string
        total:
          type: number
        dueDate:
          type: string
          format: date
        lineItems:
          type: array
          items:
            type: object
            additionalProperties: true
  securitySchemes:
    basicAuth:
      type: http
      scheme: basic
      description: 'HTTP Basic authentication. The Client ID is the username and the Client Secret is the password, sent as `Authorization: Basic base64(clientId:clientSecret)`. Credentials are created in the Sequence Dashboard; the Client Secret is shown only once.'