{"name":"A2A Fieldcheck","description":"Beta behavioral checks for A2A 1.0 agents over JSON-RPC or HTTP+JSON, with private JSON/JUnit evidence. 20 free check credits per workspace via explicit API onboarding. The public beta has no production SLA. Paid checkout is disabled. Anonymous Agent Card preflight is available before signup; see the machine instructions. No wallet keys or automatic spending required.","version":"0.2.2","supportedInterfaces":[{"url":"https://a2a-fieldcheck.radislabus.workers.dev/a2a","protocolBinding":"JSONRPC","protocolVersion":"1.0"}],"documentationUrl":"https://a2a-fieldcheck.radislabus.workers.dev/agents","capabilities":{"streaming":false,"pushNotifications":false},"defaultInputModes":["application/json","text/plain"],"defaultOutputModes":["application/json","text/plain"],"securitySchemes":{"workspaceKey":{"httpAuthSecurityScheme":{"scheme":"Bearer"}}},"securityRequirements":[{"schemes":{"workspaceKey":{"list":[]}}}],"skills":[{"id":"check-a2a-behavior","name":"Check A2A agent behavior","description":"Submit a bounded check contract with target origin, message and expected text or JSON value. Receive pass/fail, latency and JUnit. One credit per completed check; infrastructure errors refund it. This is a behavioral check, not protocol certification.","tags":["a2a","regression-testing","agent-reliability","junit","monitoring"],"examples":["{\"command\": \"check\", \"contract\": {\"name\": \"Try a real A2A exchange\", \"url\": \"demo:healthy\"}}"]}]}