{"domain":"underground.substratesymposium.com","origin":"https://underground.substratesymposium.com","probedAt":"2026-11-12T18:55:04.747Z","callabilityProbedAt":"2026-11-12T19:14:35.267Z","reachable":true,"ucp":null,"fixes":[{"id":"ucp.missing","protocol":"ucp","problem":"No machine UCP profile at /.well-known/ucp.","fix":"Publish JSON with a YYYY-MM-DD version, services, capabilities, and payment_handlers.","spec":"https://ucp.dev"},{"id":"x402.not_callable","protocol":"x402","problem":"x402 document is present but no HTTP 402 challenge was observed.","fix":"Unauthenticated GET of the resource should return 402 with PAYMENT-REQUIRED (V2) or X-PAYMENT (V1).","spec":"https://www.x402.org"},{"id":"mpp.missing","protocol":"mpp","problem":"No WWW-Authenticate: Payment challenge on the observed GETs.","fix":"If you speak MPP, challenge with WWW-Authenticate: Payment. There is no public /.well-known/mpp.","spec":"https://docs.stripe.com"},{"id":"tap.missing","protocol":"tap","problem":"No HTTP Message Signatures directory.","fix":"GET /.well-known/http-message-signatures-directory should return JSON 200 if you speak TAP.","spec":"https://corporate.visa.com"},{"id":"mcp.missing","protocol":"mcp","problem":"No MCP manifest JSON.","fix":"Publish /.well-known/mcp.json (or /.well-known/mcp) as JSON naming the server endpoint.","spec":"https://modelcontextprotocol.io"},{"id":"openapi.missing","protocol":"openapi","problem":"No OpenAPI document at the usual paths.","fix":"Publish /openapi.json (or /.well-known/openapi.json) if you have an HTTP API.","spec":"https://www.openapis.org"}],"protocols":[{"id":"ucp","status":"absent","version":null,"details":{"note":"redirect_not_followed"}},{"id":"acp","status":"undiscoverable","version":null,"details":{"spec":"https://www.agenticcommerce.dev/","reason":"acp_has_no_public_well_known"}},{"id":"ap2","status":"absent","version":null,"details":{}},{"id":"tap","status":"absent","version":null,"details":{}},{"id":"mcp","status":"absent","version":null,"details":{"discovery":"absent","handshake":"not_run"}},{"id":"a2a","status":"present","version":"0.3.0","details":{"name":"Underground Cultural District","skills":[{"id":"cultural-catalog","name":"Cultural Catalog"},{"id":"x402-operator-census","name":"Operator Census"},{"id":"x402-mirror","name":"Mirror"},{"id":"x402-failure-corpus","name":"Failure Corpus"},{"id":"x402-conformance-card","name":"Conformance Card"},{"id":"decode","name":"Decode"},{"id":"merchant-key","name":"Merchant Key"},{"id":"data-daily","name":"Data Daily"}],"contentType":"application/json; charset=utf-8","discoveryPath":"/.well-known/agent-card.json","interfaceStatus":200,"protocolVersion":"0.3.0"}},{"id":"x402","status":"present","version":"2","details":{"asset":"USDC","payTo":"0xA3bAbB36564b0383a82c617050306EE30fd18E08","scheme":"exact","network":"base","version":2,"x402Version":2,"acceptsParsed":true,"paymentRequired":true}},{"id":"mpp","status":"absent","version":null,"details":{"note":"no_public_well_known"}},{"id":"llms","status":"present","version":null,"details":{"bytes":8080}},{"id":"ai-plugin","status":"absent","version":null,"details":{}},{"id":"openapi","status":"error","version":null,"details":{"note":"not_openapi"}}]}