openapi: 3.0.3
info:
  title: OpenMeter Billing API
  description: OpenMeter is open-source usage metering and billing for AI and API products. Ingest usage as CloudEvents, define meters that aggregate those events, query usage, manage subjects and customers, gate access with entitlements (metered, boolean, and static), features and grants, react to usage with notifications, and drive billing, plans, and subscriptions with Stripe integration. This is a faithful, representative subset of the real OpenMeter Cloud API (https://openmeter.cloud/api/v1) for API Evangelist catalog purposes; see the canonical spec at https://github.com/openmeterio/openmeter for the full surface.
  termsOfService: https://openmeter.io/terms
  contact:
    name: OpenMeter Support
    url: https://openmeter.io
    email: support@openmeter.io
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
  version: 1.0.0
servers:
- url: https://openmeter.cloud
  description: OpenMeter Cloud
- url: http://localhost:8888
  description: Self-hosted (open source, default)
security:
- BearerAuth: []
tags:
- name: Billing
  description: Billing profiles, invoices, and customer overrides.
paths:
  /api/v1/billing/invoices:
    get:
      operationId: listInvoices
      tags:
      - Billing
      summary: List invoices
      responses:
        '200':
          description: List of invoices.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Invoice'
  /api/v1/billing/profiles:
    get:
      operationId: listBillingProfiles
      tags:
      - Billing
      summary: List billing profiles
      responses:
        '200':
          description: List of billing profiles.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/BillingProfile'
components:
  schemas:
    Customer:
      type: object
      required:
      - name
      properties:
        id:
          type: string
        key:
          type: string
        name:
          type: string
        currency:
          type: string
          example: USD
        usageAttribution:
          type: object
          properties:
            subjectKeys:
              type: array
              items:
                type: string
    BillingProfile:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        default:
          type: boolean
        supplier:
          type: object
          additionalProperties: true
        workflow:
          type: object
          additionalProperties: true
    Invoice:
      type: object
      properties:
        id:
          type: string
        number:
          type: string
        customer:
          $ref: '#/components/schemas/Customer'
        status:
          type: string
          enum:
          - draft
          - issued
          - paid
          - void
        currency:
          type: string
        total:
          type: string
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      description: OpenMeter Cloud API token supplied as a Bearer token.