generated: '2026-09-19' method: probed source: https://mcp.hakuto-0209.com/.well-known/agent-card.json card: file: a2a/hakuto-0209-com-agent-card.json discovery: path: /.well-known/agent-card.json canonical: true host: mcp.hakuto-0209.com note: >- Served from mcp.hakuto-0209.com, a subdomain of the provider's registrable domain that is also the MCP server host and the A2A JSON-RPC host. The apex hakuto-0209.com (a Vercel static marketing site) 404s both well-known card paths with Vercel's text/plain NOT_FOUND body. The same deployment is reachable at its Vercel project host b612-a2a.vercel.app — the URL the a2aregistry.org listing pointed at — and the two hosts return byte-identical cards, so the vercel.app host is the origin and mcp.hakuto-0209.com is the provider's own name for it; the record uses the provider's domain. The legacy /.well-known/agent.json is ALSO served (200, 7,263 bytes) and is the identical card with the signatures[] block omitted. Every other /.well-known/* path on the host (and a negative-control path that cannot exist) returns an Express "Cannot GET" text/html 404, so the 200s are served documents, not a catch-all. Ownership is not in question: the card's provider.organization is "HaneruTo" with provider.url https://hakuto-0209.com, the apex site links the same info@hakuto-0209.com contact the data policy names, and the JWS signature's jku points back at this host's own JWKS. x-evidence: fetched: '2026-09-19' url: https://mcp.hakuto-0209.com/.well-known/agent-card.json http_status: 200 content_type: application/json; charset=utf-8 body_bytes: 7527 body_parses_as: JSON object with AgentCard shape (name, description, version, url, preferredTransport, protocolVersion, capabilities, defaultInputModes, defaultOutputModes, skills, provider, documentationUrl, securitySchemes, security, supportedInterfaces, signatures) signature_verification: verified: true method: >- JWS (RFC 7515) with protected header {alg: EdDSA, kid: b612-a2a-2026-09, jku: https://mcp.hakuto-0209.com/.well-known/jwks.json}; payload = the card without signatures[], canonicalised per RFC 8785 (JCS); verified 2026-09-19 with the Ed25519 key of matching kid from the published JWKS. A non-canonical (insertion-order) payload does NOT verify, so the signer used JCS as the A2A specification requires. jwks: well-known/hakuto-0209-com-jwks.json corroborating_probes: - url: https://mcp.hakuto-0209.com/.well-known/agent.json http_status: 200 note: Legacy pre-0.3 path. Same card without the signatures[] block (7,263 bytes). - url: https://b612-a2a.vercel.app/.well-known/agent-card.json http_status: 200 note: Byte-identical to the mcp.hakuto-0209.com card; this is the Vercel origin behind the custom domain. - url: https://hakuto-0209.com/.well-known/agent-card.json http_status: 404 - url: https://hakuto-0209.com/.well-known/agent.json http_status: 404 - url: https://mcp.hakuto-0209.com/.well-known/jwks.json http_status: 200 note: One Ed25519 (OKP) key, kid b612-a2a-2026-09, use sig, alg EdDSA. - url: https://mcp.hakuto-0209.com/.well-known/apievangelist-negative-control-7f3a9c.json http_status: 404 note: Negative control — a path that cannot exist also 404s, so the host is not a catch-all. - url: https://mcp.hakuto-0209.com/a2a/v1 method: GET http_status: 401 response: '{"error":{"code":"unauthenticated","message":"APIキー（b612 ライセンスキー）が指定されていません","hint":"ヘッダー x-b612-key に b612 のライセンスキーを入れてください。キー無しでも次のスキルは試せます: principles / rules（データ取扱いは https://mcp.hakuto-0209.com/terms）"}}' - url: https://mcp.hakuto-0209.com/a2a/v1 method: POST body: '{"jsonrpc":"2.0","id":1,"method":"tasks/get","params":{"id":"apievangelist-nonexistent-probe"}}' http_status: 401 note: >- Same unauthenticated envelope. The gate sits in front of the JSON-RPC dispatcher: without an x-b612-key header no A2A method is reachable, including the two skills (principles, rules) the card and the 401 hint both describe as keyless. Not resolved here — no key was requested and no message was sent with one. The keyless tier IS reachable over MCP (see mcp/). - url: https://a2aregistry.org note: >- First seen as one of 415 agents on a2aregistry.org (fetched 2026-09-19, author "HaneruTo", card URL https://b612-a2a.vercel.app/.well-known/agent-card.json), which is how the provider entered the harvest backlog. The card above was fetched directly from the provider's own host. agent_card: name: b612 description: >- Japanese-market code review agent. Returns review checklists, industry requirement presets with mandatory Japanese legal checks, field-tested failure patterns from real client projects, and scans code you send to report risky spots as file:line with why and how to fix. Deterministic checks — no LLM inference. Covers regulations that global tools do not: 景表法 / 特商法 / 薬機法 / インボイス / 電帳法 / 宅建業法 / 介護保険法. Free to try: principles and rules need no key (20 req/min per IP); agent-to-agent access is a monthly flat fee with a call cap, priced on contact. url: https://mcp.hakuto-0209.com/a2a/v1 version: 0.1.0 protocol_version: '0.3' preferred_transport: JSONRPC provider: organization: HaneruTo url: https://hakuto-0209.com documentation_url: https://mcp.hakuto-0209.com/terms capabilities: streaming: false push_notifications: false default_input_modes: [text/plain, application/json] default_output_modes: [text/plain] security_schemes: b612ApiKey: {type: apiKey, in: header, name: x-b612-key} security: [{b612ApiKey: []}] supports_authenticated_extended_card: false supported_interfaces: - {url: https://mcp.hakuto-0209.com/a2a/v1, protocolBinding: JSONRPC, protocolVersion: '1.0'} - {url: https://mcp.hakuto-0209.com/a2a/v1, protocolBinding: JSONRPC, protocolVersion: '0.3'} signatures: 1 (EdDSA, kid b612-a2a-2026-09, verified — see x-evidence) skill_count: 6 skills: - {id: principles, name: Review principles / b612 の思考原則, tags: [code-review, principles, engineering-discipline, japanese], keyless: true} - {id: review-checklist, name: Review checklist by target type / 対象別レビュー観点, tags: [code-review, checklist, landing-page, ecommerce, saas, japanese]} - {id: patterns, name: Field-tested failure patterns / 実戦パターン, tags: [postmortem, lessons-learned, debugging, japanese, line-messaging-api]} - {id: domain-preset, name: Industry presets (Japan) / 業種別プリセット, tags: [japanese-law, compliance-jp, keihyoho, tokushoho, yakkiho, invoice-jp, domain-model, requirements]} - {id: scan-code, name: Scan code and report findings / コード検査, tags: [static-analysis, code-review, security, bug-detection, japanese]} - {id: rules, name: Detection rules / 検出ルール一覧, tags: [static-analysis, transparency, rules], keyless: true} skill_invocation: >- Every skill carries bilingual examples[] as plain-text prompts (e.g. "What rules does your scanner apply?"), inputModes text/plain + application/json and outputModes text/plain. scan-code is the only skill that takes source text; the data policy states it is analysed in memory and discarded. conformance: spec: A2A 1.0.0 grade: conformant protocol_version: '0.3' preferred_transport: JSONRPC hard_checks: capabilities_is_object: true protocol_version_present: true skills_is_array: true optional_fields: default_input_modes: true default_output_modes: true preferred_transport: true grade_basis: >- Graded against the A2A 1.0.0 hard checks. capabilities is an OBJECT (pass) with streaming and pushNotifications. protocolVersion is present at the top level (pass), declared as "0.3". skills is an ARRAY (pass) of six fully-populated skills, each with id, name, description, tags, examples, inputModes and outputModes. All three optional discriminators are present. The card additionally carries the 1.0.0-style supportedInterfaces[] block (two entries on one URL, protocolVersion 1.0 and 0.3), a securitySchemes/security pair, provider, documentationUrl and a verified JWS signature — a more complete card than most in the catalog. deviations: - field: protocolVersion vs supportedInterfaces[].protocolVersion observed: top-level "0.3"; supportedInterfaces[] declares both "1.0" and "0.3" for the same JSON-RPC URL note: >- The card is a hybrid of the 0.3 top-level triple (url/preferredTransport/protocolVersion) and the 1.0 supportedInterfaces[] block. Internally consistent (one endpoint, one binding) and readable by clients written against either revision; recorded because the top-level protocolVersion under-states what the interfaces block advertises. - field: securitySchemes / security vs observed behaviour observed: >- The card requires b612ApiKey on every skill while its own description and the endpoint's 401 hint say principles and rules are usable without a key; an unauthenticated JSON-RPC POST is refused before dispatch (401 on tasks/get). note: The keyless tier is real over MCP (tools/list and tools/call b612_principles answered anonymously); over A2A it was not reachable in this probe. - field: signatures[] observed: present and verifiable note: Recorded as a strength, not a fault — see x-evidence.signature_verification. surface_relationship: note: >- HaneruTo publishes two agent surfaces on one host, both fronting the same b612 knowledge base. A2A: six skills at https://mcp.hakuto-0209.com/a2a/v1 behind x-b612-key. MCP: ten tools at https://mcp.hakuto-0209.com/mcp, anonymous tools/list, where four tools (design, reference, grow, notes) and the update procedure have no A2A skill counterpart and A2A's scan-code has no MCP tool — the MCP server's own instructions state it has no input for source code, so scanning happens client-side against b612_rules over MCP but server-side over A2A. No REST/OpenAPI surface exists (see mcp/hakuto-0209-com-mcp.yml); a tool crosswalk is therefore not emitted.