openapi: 3.2.0
info:
  title: Agent Verification Utility A2a API
  version: 0.4.3
  description: A deterministic, x402-paid JSON evidence verification service for external agents. The service attests that declared checks were executed; it does not attest real-world truth.
  license:
    name: UNLICENSED
servers:
- url: /
  description: Relative to the current deployment origin
security: []
tags:
- name: a2a
  description: Synchronous A2A 1.0 JSON-RPC quote preparation
paths:
  /.well-known/agent-card.json:
    get:
      operationId: getA2aAgentCard
      summary: Get the A2A 1.0 Agent Card
      description: Advertises the synchronous JSON-RPC interface and its bounded quote-preparation skill.
      tags:
      - a2a
      responses:
        '200':
          description: A2A Agent Card
          content:
            application/json:
              schema:
                type: object
  /a2a:
    post:
      operationId: sendA2aMessage
      summary: Use the A2A 1.0 JSON-RPC interface
      description: Implements A2A 1.0 SendMessage for idempotent quote preparation. The message must contain one application/json data part with idempotency_key and intent; intent includes the unchanged request and spend policy plus the digest returned by the free precheck. The returned agent message contains a bound quote and purchase instructions; it does not execute paid work. Because this adapter never creates A2A Tasks, ListTasks returns an empty collection while GetTask and CancelTask return TaskNotFoundError. Streaming, push notifications, and extended cards return their capability-specific A2A errors.
      tags:
      - a2a
      parameters:
      - name: A2A-Version
        in: header
        required: true
        schema:
          type: string
          const: '1.0'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
      responses:
        '200':
          description: JSON-RPC result or error
          headers:
            A2A-Version:
              required: true
              schema:
                type: string
                const: '1.0'
          content:
            application/json:
              schema:
                type: object
        '405':
          description: Only POST is supported
components:
  securitySchemes:
    agentRegistration:
      type: http
      scheme: bearer
      bearerFormat: signed anonymous registration receipt
      description: Optional 15-minute service-local receipt used only to inspect its own registration claim. It grants no API access and does not authorize payment.