Kagura AI Billing Handoff API

openapi: 3.2.0
info:
  title: Kagura Memory Cloud Billing Handoff API
  description: Universal AI Memory Platform - Remote MCP Server + Web Management
  version: 0.158.1
tags:
- name: billing-handoff
  description: Create a signed handoff from Memory Cloud to the external billing service
paths:
  /api/v1/billing/handoff:
    post:
      tags:
      - billing-handoff
      summary: Mint Billing Handoff
      description: 'Mint an owner-scoped, short-lived billing handoff token.


        Owner-only + session-only. Returns 403 for admin/member/API-key callers and

        503 when the signing key is unconfigured (fail-closed).


        The token''s ``iss`` / ``aud`` claims (``billing_handoff_issuer`` /

        ``billing_handoff_audience``) are FROZEN cross-repo JWT contract values

        verified by the external billing service — they are NOT repo or service

        names. ``billing`` is the function; the external service provides it.

        Changing either claim is a coordinated breaking change (the verifier must

        change in lockstep), never a local rename.'
      operationId: mint_billing_handoff_api_v1_billing_handoff_post
      parameters:
      - name: authorization
        in: header
        required: false
        schema:
          anyOf:
          - type: string
          - type: 'null'
          title: Authorization
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/BillingHandoffRequest'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BillingHandoffResponse'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    BillingHandoffResponse:
      properties:
        token:
          title: Token
          description: Ed25519-signed JWT (alg=Ed25519, RFC 9864).
        token_type:
          title: Token Type
          description: Token kind discriminator.
        kid:
          title: Kid
          description: Signing key id — selects the verifier's public key.
        jti:
          title: Jti
          description: Unique token id (verifier enforces single-use).
        expires_at:
          title: Expires At
          description: Token expiry (UTC, short-lived).
        url:
          title: Url
          description: 'Ready-to-use redirect URL ({base}/enter?t={token}) when payment_public_base_url is configured; null otherwise (the decoupled raw-token contract, #1098). The caller redirects the owner''s browser here.'
      type: object
      required:
      - token
      - kid
      - jti
      - expires_at
      title: BillingHandoffResponse
      description: The minted handoff token and the metadata the billing host needs.
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
            - type: string
            - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
      - loc
      - msg
      - type
      title: ValidationError
    BillingHandoffRequest:
      properties:
        workspace_id:
          type: string
          format: uuid
          title: Workspace Id
          description: The workspace to start a billing session for. The caller MUST be its owner — the owner check binds to this value, not the session's current workspace.
      type: object
      required:
      - workspace_id
      title: BillingHandoffRequest
      description: Request to mint a handoff token for one owned workspace.