openapi: 3.0.3
info:
  title: OpenMeter Billing Grants 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: Grants
  description: Usage grants that top up metered entitlement balances.
paths:
  /api/v1/subjects/{subjectIdOrKey}/entitlements/{entitlementIdOrFeatureKey}/grants:
    parameters:
    - name: subjectIdOrKey
      in: path
      required: true
      schema:
        type: string
    - name: entitlementIdOrFeatureKey
      in: path
      required: true
      schema:
        type: string
    get:
      operationId: listEntitlementGrants
      tags:
      - Grants
      summary: List subject entitlement grants
      responses:
        '200':
          description: Grants for the entitlement.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Grant'
    post:
      operationId: createGrant
      tags:
      - Grants
      summary: Create a grant on an entitlement
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Grant'
      responses:
        '201':
          description: Grant created.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Grant'
  /api/v1/grants:
    get:
      operationId: listGrants
      tags:
      - Grants
      summary: List grants
      responses:
        '200':
          description: List of grants.
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Grant'
  /api/v1/grants/{grantId}:
    delete:
      operationId: voidGrant
      tags:
      - Grants
      summary: Void grant
      parameters:
      - name: grantId
        in: path
        required: true
        schema:
          type: string
      responses:
        '204':
          description: Grant voided.
components:
  schemas:
    Grant:
      type: object
      required:
      - amount
      properties:
        id:
          type: string
        amount:
          type: number
          description: Amount of usage to grant to the entitlement balance.
        priority:
          type: integer
          description: Lower priority grants are burned down first.
          default: 1
        effectiveAt:
          type: string
          format: date-time
        expiration:
          type: object
          properties:
            duration:
              type: string
              enum:
              - HOUR
              - DAY
              - WEEK
              - MONTH
              - YEAR
            count:
              type: integer
        recurrence:
          type: object
          properties:
            interval:
              type: string
              enum:
              - DAY
              - WEEK
              - MONTH
              - YEAR
            anchor:
              type: string
              format: date-time
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      description: OpenMeter Cloud API token supplied as a Bearer token.