generated: '2026-09-19'
method: probed
status: published
source: https://mcp.horizonshield.dev/
docs: https://github.com/ogasurfproject-jpg/horizon-shield#readme
registry_listings:
- registry: registry.modelcontextprotocol.io
  name: dev.horizonshield/horizon-shield
  version: 1.0.9
  remote: {type: streamable-http, url: 'https://mcp.horizonshield.dev/mcp'}
  url: https://registry.modelcontextprotocol.io/v0/servers?search=horizon
  note: The dev.horizonshield namespace is DNS-verified — the apex horizonshield.dev TXT record "v=MCPv1; k=ed25519; p=7fwx4Ib4DBGNd+0Yi34/nXEJZ6nFYOoudUR1gA/TwHc=" is the MCP registry's domain-ownership proof. A second server.json (io.github.ogasurfproject-jpg/horizon-shield, same remote) is published at https://shield.the-horizons-innovation.com/server.json.
- registry: glama.ai
  url: https://glama.ai/mcp/servers/ogasurfproject-jpg/horizon-shield
  note: /.well-known/glama.json is served on the MCP host (maintainers[0].email ogasurfproject@gmail.com). The Glama API itself is key-gated (401) so the listing was not read here.
- registry: smithery.ai
  url: https://smithery.ai/server/oga-surf-project/horizon-shield
  note: Named in the provider's llms.txt; not probed.
summary: >-
  HORIZON SHIELD operates a FAMILY of remote MCP servers on subdomains of horizonshield.dev (the apex resolves to
  nothing; see well-known/). The flagship is https://mcp.horizonshield.dev/ — POST-only Streamable HTTP, MCP
  protocol 2025-06-18, serverInfo {horizon-shield, 1.0.9}, anonymous. It answered initialize, tools/list (15 tools,
  every one with inputSchema AND outputSchema and readOnly/destructive/openWorld annotations), prompts/list (5
  prompts) and ping without any credential; resources/list returns -32601. GET on / , /mcp and /sse returns a
  deliberate 405 whose JSON body explains the transport, lists the tools and known paths, and dates the retirement
  of the legacy SSE path (2026-08-14). The same JSON-RPC URL also answers A2A message/send (see a2a/). Authorship is
  the provider's own: tool names, bilingual JP/EN descriptions, the JCCDB dataset, the PTKA receipt model and the
  AP2 attestation bridge match no shared platform fingerprint, and the source is public at
  github.com/ogasurfproject-jpg/horizon-shield (workers/hs-mcp). Five sibling servers (gate, JIDEC, WebMCP intake,
  Yakumo, femtech) were probed the same way and are recorded below with their tool lists saved verbatim.
deployment:
  mode: both
  endpoint: https://mcp.horizonshield.dev/
  install: 'uvx --from "git+https://github.com/ogasurfproject-jpg/horizon-shield#subdirectory=workers/hs-ledger/nenrin/a2a-conduct-walk" conduct-witness-mcp'
  package: https://github.com/ogasurfproject-jpg/horizon-shield/tree/main/workers/hs-ledger/nenrin/a2a-conduct-walk
  auth: none
  verified: probed
  note: >-
    The endpoint is a hosted HTTPS URL an MCP client POSTs to directly (the root, /mcp and /sse all accept the same
    JSON-RPC; the provider's registry entries name /mcp, its gemini-extension.json and lhm.plugin.json name the
    root). The stdio component is DIFFERENT software: conduct-witness-mcp, a standard-library Python MCP server
    shipped in the a2a-conduct-walk distribution (pyproject project.scripts; "Also an MCP server
    (conduct-witness-mcp) so any agent can be a witness in one tool call"), installed with uvx straight from the
    GitHub subdirectory because it is not on PyPI. It files witness walks on the ledger; it is not a local copy of
    KIRA. The provider's Claude Code plugin (/plugin marketplace add ogasurfproject-jpg/horizon-shield; /plugin
    install horizon-shield@the-horizons) bundles a REMOTE connector to the hosted URL plus a skill and three slash
    commands (/audit, /red-flags, /verify) — a human installs it, but the connection it opens is to the hosted
    server, so it does not by itself make the mode local. A Gemini CLI extension manifest (https://shield.the-horizons-innovation.com/gemini-extension.json,
    httpUrl https://mcp.horizonshield.dev) and an LM-Studio-style plugin manifest (/lhm.plugin.json, cloudEndpoint the
    same URL) are also published. auth is none in the connection sense: initialize and tools/list need nothing and no
    OAuth metadata is served on the MCP host (/.well-known/oauth-authorization-server and
    /.well-known/oauth-protected-resource both return the server's real JSON 404).
servers:
- id: kira
  name: HORIZON SHIELD KIRA (horizon-shield)
  endpoint: https://mcp.horizonshield.dev/
  aliases: ['https://mcp.horizonshield.dev/mcp', 'https://mcp.horizonshield.dev/sse (accepts POST; GET 405 sse_not_supported)', 'https://hs-mcp.oga-surf-project.workers.dev/ (Workers origin)']
  transport: streamable-http
  http_methods: [POST]
  auth: none
  status: live
  authorship: provider
  probe:
    fetched: '2026-09-19'
    initialize:
      http_status: 200
      protocol_version: '2025-06-18'
      server_info: {name: horizon-shield, version: 1.0.9}
      capabilities: {tools: {}, prompts: {}}
      instructions_excerpt: >-
        HORIZON SHIELD: independent, buyer-side fair-price verification for construction and renovation work in
        Japan (prices in JPY). … Tool order: get_price_range when no quote exists yet …; audit_estimate when the user
        has a specific quoted amount; check_red_flags for suspicious wording …; verify_fair_price when a
        hash-verifiable record is needed …; find_verified_contractor when the user asks who to hire … Scope and
        honesty: Japan only; … when candidates disagree the server returns ambiguous instead of a verdict; the
        service takes no referral or listing fee from contractors.
    tools_list: {http_status: 200, content_type: 'application/json; charset=utf-8', tool_count: 15, file: mcp/horizonshield-dev-mcp-tools.json}
    prompts_list: {http_status: 200, prompt_count: 5, file: mcp/horizonshield-dev-mcp-prompts.json, prompts: [audit_my_estimate, know_fair_price_first, verify_receipt, ap2_cart_fairness, spot_sales_tactics]}
    resources_list: {http_status: 200, error: '-32601 Method not found: resources/list'}
    ping: {http_status: 200, result: {}}
    get_request: {http_status: 405, allow: POST, body_excerpt: '{"server":{"name":"horizon-shield","version":"1.0.9"},"transport":"MCP over Streamable HTTP (JSON-RPC 2.0)","usage":"POST JSON-RPC 2.0 to this URL. methods: initialize, tools/list, tools/call, prompts/list, prompts/get.","sse":"not offered …","tools":[…15…],"site":"https://shield.the-horizons-innovation.com"}'}
    health: {url: 'https://mcp.horizonshield.dev/health', http_status: 200, body: '{"ok":true,"server":{"name":"horizon-shield","version":"1.0.9"},"checked":{"worker":"running","kv":"reachable"},"not_checked":["data freshness","tool output correctness"]}'}
    tools_call: {tool: get_agent_card, http_status: 200, note: 'The only tool invoked — read-only, argument-free; it returned the card URL, the verification-contract URL, the provider name and the three skill ids. No price tool and no ledger-appending tool was called.'}
  tools:
  - {name: get_jccdb_dataset_info, read_only: true, required: [], description: 'JCCDB dataset metadata: scale (95,403 items), license (CC BY 4.0), download links, citation.'}
  - {name: list_cost_categories, read_only: true, required: [], description: 'The 61 construction/renovation categories with maintained fair-price ranges and red flags (Japan).'}
  - {name: search_cost_category, read_only: true, required: [query], description: Find a maintained cost category by work name.}
  - {name: get_estimate_reading_guide, read_only: true, required: [], description: 'Principles for judging whether an estimate is fair, including the overhead-share guide.'}
  - {name: get_fair_price_sources, read_only: true, required: [], description: Sources and regional multipliers behind the price layer.}
  - {name: get_price_range, read_only: true, required: [query], optional: [region], description: 'Fair min/avg/max and the overcharge danger threshold for a work type, regionally adjusted when region is passed.'}
  - {name: audit_estimate, read_only: true, required: [work, quoted_price], optional: [region], description: 'Judge a quoted JPY price against the fair range: verdict, level (ok/watch/alert), fair_range, danger_threshold, vs_avg_pct, advice, source; did_you_mean on no match; unit_mismatch guidance.'}
  - {name: preview_reverse_estimate, read_only: true, required: [work, quoted_price], description: Direction of a rough estimate versus the average.}
  - {name: check_red_flags, read_only: true, required: [text], description: 'Known overcharge and high-pressure tactics in estimate or sales wording (lump sum, today-only discount, free inspection, door-to-door). Language-agnostic.'}
  - {name: verify_fair_price, read_only: true, required: [work], description: 'A fair price as a SHA-256 tamper-evident receipt with a per-receipt verify_url (https://shield.the-horizons-innovation.com/verify/?id=CLAIM_SHA256) and a JSON copy at /ledger/{claim_sha256}.'}
  - {name: create_ap2_fairness_attestation, read_only: false, idempotent: false, destructive: false, required: [work], optional: [quoted_price, merchant], description: 'AP2 bridge: issues a FairPriceAttestation shaped to attach to a Google AP2 Cart Mandate. The tool states it initiates, authorizes and executes NO payment and moves no funds; each call APPENDS one record to the public ledger, which is why it is not read-only.'}
  - {name: suggest_ehn, read_only: true, required: [], description: Guide and submission URL for EHN (Estimate Hacker News), the free anonymous third-party review board.}
  - {name: get_agent_card, read_only: true, required: [], description: A2A discovery — returns the card URL, verification contract URL, provider and skill ids.}
  - {name: verify_integrity_claim, read_only: true, required: [signed_payload, claim_sha256], optional: [estimate_version], description: 'Independently recompute a signed verdict, fail closed: result verified / partial / unverified with failure_reason (stale_data / changed_scope / missing_evidence) per verification contract 0.3.'}
  - {name: find_verified_contractor, read_only: true, required: [], optional: [area, work], description: 'Verification-passed contractors on Yakumo; scores and tiers, never prices; pending stores returned separately; returns 0 honestly.'}
  output_contract_note: >-
    Every tool declares an outputSchema. Read tools share a convention worth recording because agents can act on
    it: `lookup` is "ok" or "absent", `source_read` is true on every successful result, `count` 0 means the source
    was read and nothing matched, and a source that could NOT be read never returns a result at all — it returns
    isError: true. Price answers additionally carry provenance (dataset version, curator, sources), next_calls (the
    next tool with arguments pre-filled) and next_actions.
- id: gate
  name: MCP Verification Gate (MCP conduct register)
  endpoint: https://gate.horizonshield.dev/mcp
  transport: streamable-http
  http_methods: [POST]
  auth: none
  status: live
  authorship: provider
  openapi: openapi/horizonshield-dev-mcp-conduct-register-openapi.json
  probe:
    fetched: '2026-09-19'
    tools_list: {http_status: 200, tool_count: 5, file: mcp/horizonshield-dev-gate-mcp-tools.json}
    tools: [get_conditions, check_conformance, verify_verdict, lookup_server, is_verified]
    note: 'Every tool is annotated readOnlyHint true; check_conformance is idempotentHint false because it triggers a live measurement of the named endpoint. POST /mcp is also declared as a path in the gate''s OpenAPI ("The same register over MCP").'
- id: jidec
  name: HORIZON SHIELD JIDEC (read-only ledger MCP)
  endpoint: https://jidec.horizonshield.dev/mcp
  aliases: ['https://hs-jidec-mcp.oga-surf-project.workers.dev/mcp (Workers origin)']
  transport: streamable-http
  http_methods: [POST]
  auth: none
  status: live
  authorship: provider
  probe:
    fetched: '2026-09-19'
    tools_list: {http_status: 200, tool_count: 4, file: mcp/horizonshield-dev-jidec-mcp-tools.json}
    tools: [jidec_cite, jidec_replay, jidec_list_paths, jidec_how_to_verify]
    get_request: {http_status: 405, body: '{"ok":false,"error":"method_not_allowed","detail":"This MCP endpoint is stateless and offers no server-initiated SSE stream. Use POST."}'}
    note: 'With Accept: application/json, text/event-stream the server answers as an SSE frame (event: message / data: {...}); with Accept: application/json it answers plain JSON. All four tools are readOnlyHint + idempotentHint true.'
- id: webmcp
  name: HORIZON SHIELD WebMCP intake (hs-webmcp)
  endpoint: https://web.horizonshield.dev/mcp
  transport: streamable-http
  http_methods: [POST]
  auth: none
  status: live
  authorship: provider
  registry: 'server.json at https://shield.the-horizons-innovation.com/server-webmcp.json (io.github.ogasurfproject-jpg/horizon-shield-webmcp, 1.0.0)'
  probe:
    fetched: '2026-09-19'
    initialize: {http_status: 200, protocol_version: '2025-06-18', server_info: {name: hs-webmcp, title: HORIZON SHIELD WebMCP (KIRA), version: 1.0.4}, capabilities: [tools, resources, prompts, completions, logging]}
    tools_list: {http_status: 200, tool_count: 5, file: mcp/horizonshield-dev-webmcp-tools.json}
    tools: [route_request, run_full_audit, intake_estimate, scan_tactics, draft_broadcast]
    get_request: {http_status: 405, body: 'Method Not Allowed. Use POST for JSON-RPC.'}
- id: yakumo
  name: HORIZON SHIELD YAKUMO (verified-contractor directory)
  endpoint: https://hearing.horizonshield.dev/mcp
  transport: streamable-http
  http_methods: [POST]
  auth: none
  status: live
  authorship: provider
  probe:
    fetched: '2026-09-19'
    initialize: {http_status: 200, protocol_version: '2025-06-18', server_info: {name: HORIZON SHIELD YAKUMO, version: 2.3.1}, capabilities: [tools, resources, prompts, completions]}
    tools_list: {http_status: 200, tool_count: 6, file: mcp/horizonshield-dev-yakumo-mcp-tools.json}
    tools: [list_verified_stores, get_contractor_profile, find_contractor, mall_overview, how_verification_works, check_named_contractor]
    note: All six tools readOnlyHint + idempotentHint true; the server returns scores and tiers, never prices.
- id: femtech
  name: HORIZON SHIELD Femtech Registry (hs-femtech-mcp)
  endpoint: https://femtech.horizonshield.dev/mcp
  transport: streamable-http
  http_methods: [POST]
  auth: none
  status: live
  authorship: provider
  source_repo: https://github.com/ogasurfproject-jpg/hs-femtech-mcp
  probe:
    fetched: '2026-09-19'
    initialize: {http_status: 200, protocol_version: '2024-11-05', server_info: {name: hs-femtech-mcp, version: 0.4.1}, capabilities: [tools]}
    tools_list: {http_status: 200, tool_count: 9, file: mcp/horizonshield-dev-femtech-mcp-tools.json}
    tools: [register_source, list_registry, get_registry_entry, verify_source, get_femtech_topic, explain_product_category, how_to_verify, get_agent_card, check_source]
    get_request: {http_status: 200, note: 'GET /mcp returns a JSON descriptor (server, version, endpoints) rather than 405 — the one server in the family that does not follow the Streamable HTTP GET rule.'}
    note: register_source is the one write tool (readOnlyHint false) — it appends a registry entry after machine checks.
hosted_for_partners:
  note: >-
    The gate's watchlist and the register also name https://p001.horizonshield.dev/mcp and https://p002.horizonshield.dev/mcp
    (probed: live, one tool each, get_partner_profile). Their agent cards name the Yakumo member contractors as
    provider.organization, so they are contractor agents that HORIZON SHIELD builds and hosts under its "WebMCP
    Partner" plan, not this company's own surface. Recorded for completeness; not counted above.
well_known_on_mcp_host:
  served:
  - {path: /.well-known/agent-card.json, status: 200, file: a2a/horizonshield-dev-agent-card.json}
  - {path: /.well-known/verification-contract.json, status: 200, file: well-known/horizonshield-dev-verification-contract.json}
  - {path: /.well-known/jwks.json, status: 200, file: well-known/horizonshield-dev-jwks.json}
  - {path: /.well-known/glama.json, status: 200, file: well-known/horizonshield-dev-glama.json}
  - {path: /.well-known/usage-stats.json, status: 200, file: well-known/horizonshield-dev-usage-stats.json}
  absent: [/.well-known/oauth-protected-resource, /.well-known/oauth-authorization-server, /.well-known/openid-configuration, /.well-known/security.txt, /.well-known/api-catalog, /.well-known/ai-plugin.json, /.well-known/apis.json, /openapi.json, /llms.txt]
  note: See well-known/horizonshield-dev-well-known.yml for the full hosts[] -> documents[] index.
clients_documented:
- {client: Claude Code / Cowork plugin, install: '/plugin marketplace add ogasurfproject-jpg/horizon-shield; /plugin install horizon-shield@the-horizons', source: 'https://github.com/ogasurfproject-jpg/horizon-shield/blob/main/plugin/README.md'}
- {client: Gemini CLI extension, manifest: 'https://shield.the-horizons-innovation.com/gemini-extension.json'}
- {client: custom GPT (ChatGPT), url: 'https://chatgpt.com/g/g-69e180f9a5048191886069dd58b22572-jian-she-fei-tietuka-by-horizon-shield', note: Linked from the site home page.}
- {client: Gemini Gem, url: 'https://gemini.google.com/gem/1_AqLRwNSP1tZWZNWzyNIrsOrBLI1fAjo', note: Linked from the site home page.}