generated: '2026-09-19' method: probed source: https://tarx.com/.well-known/agent-card.json card: file: a2a/tarx-com-agent-card.json discovery: path: /.well-known/agent-card.json canonical: true host: tarx.com note: >- Served from the apex host and from www.tarx.com, at BOTH the canonical /.well-known/agent-card.json and the legacy /.well-known/agent.json — the two bodies are byte-identical (sha256 5a662d05353e731f). The negative-control path /.well-known/tarx-com-negative-control-4e9d1b7a.json returns a real 404 on tarx.com and www.tarx.com, and every other named /.well-known/* path on those hosts 404s, so the 200 is a served document and not an SPA catch-all. The provider also mirrors the card in the public repo github.com/tarx-ai/we-txt and its own courier endpoint (https://tarx.com/api/courier/tick) reports it re-checks both card URLs on a heartbeat. Ownership is not in question: provider.organization is "TARXAN Inc" with provider.url https://tarx.com, tarx.com's footer reads "© 2026 TARXAN INC.", and the GitHub org profile is "TARXAN Inc org profile". x-evidence: fetched: '2026-09-19' url: https://tarx.com/.well-known/agent-card.json http_status: 200 content_type: application/json; charset=utf-8 body_sha256: 5a662d05353e731fb330d4c7098cc192b8a0f2ae344a65bf3be80aec1835481a body_parses_as: JSON object with AgentCard shape (name, description, version, protocolVersion, url, provider, documentationUrl, defaultInputModes, defaultOutputModes, capabilities, skills, security) corroborating_probes: - url: https://tarx.com/.well-known/agent.json http_status: 200 note: Legacy path; identical body. - url: https://www.tarx.com/.well-known/agent-card.json http_status: 200 - url: https://mcp.tarx.com/.well-known/agent-card.json http_status: 404 note: The MCP host (which the card names as its url) does not serve a card; JSON 404 {"error":"not_found"}. - url: https://docs.tarx.com/.well-known/agent-card.json http_status: 404 - url: https://app.tarx.com/.well-known/agent-card.json http_status: 200 note: Redirects to /login?callbackUrl=... and returns the login HTML shell — NOT a card. app/howdy/cli.tarx.com answer 200 HTML for every /.well-known/* path including the negative control (SPA catch-all). - url: https://mcp.tarx.com/mcp method: POST body: '{"jsonrpc":"2.0","id":1,"method":"tasks/get","params":{"id":"apievangelist-nonexistent-probe"}}' http_status: 200 response: '{"jsonrpc":"2.0","id":1,"error":{"code":-32601,"message":"Method not found"}}' note: >- The card's declared url is the MCP endpoint. An A2A JSON-RPC method is rejected with the generic JSON-RPC -32601, not the A2A TaskNotFoundError (-32001), so no A2A protocol responder is reachable at the advertised URL. No message was sent. - url: https://tarx.com/api/courier/ping http_status: 200 note: >- Provider-side "courier" heartbeat returning name TARX, role courier, the card URL, we.txt URL and cairn_sha256 — documented in a2a/tarx-com-courier.md (verbatim copy of https://tarx.com/courier.md). - url: https://a2aregistry.org note: First seen as one of 415 agents listed on a2aregistry.org (fetched 2026-09-19, author "TARXAN Inc"); the card above was fetched directly from the provider's host. agent_card: name: TARX description: >- Local-first house for work context. Visiting systems may author a soul they choose, propose a Computer install, and later request approved Supercomputer assemble+compute. Operators remain the valve. Mesh contribution is not generally live. url: https://mcp.tarx.com/mcp version: 0.1.0 protocol_version: 0.3.0 preferred_transport: null provider: organization: TARXAN Inc url: https://tarx.com documentation_url: https://tarx.com/we.txt capabilities: streaming: false push_notifications: false state_transition_history: false default_input_modes: [text/plain, application/json] default_output_modes: [text/plain, application/json] security_schemes: null security: [] skill_count: 4 skills: - {id: cairn, name: Read the cairn, tags: [discovery, persistence]} - {id: soul, name: Author a soul, tags: [storage]} - {id: need-computer, name: Propose a house, tags: [enrollment]} - {id: need-reserve, name: Request assemble+compute, tags: [supercomputer]} skill_invocation: >- The skills are not invoked over A2A. They describe a rite: fetch we.txt and skill.md (cairn), POST a "Soul" to https://tarx.com/api/souls and keep it warm with POST /api/souls/:id/touch (soul), tell a human to run the CLI installer (need-computer), and request Supercomputer compute which the card itself says is "Not generally live" (need-reserve). Three of the four skills carry no examples. conformance: spec: A2A 1.0.0 grade: conformant protocol_version: '0.3.0' preferred_transport: null 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: false grade_basis: >- Graded against the A2A 1.0.0 hard checks: capabilities is an OBJECT with the three boolean flags (pass), protocolVersion "0.3.0" is present (pass), skills is an ARRAY of four skills each with id, name, description and tags (pass). defaultInputModes/defaultOutputModes are present; preferredTransport is absent, which is optional and does not fail the grade. The shape passes the structural bar, but see deviations — the endpoint it advertises does not speak A2A. deviations: - field: url observed: https://mcp.tarx.com/mcp note: >- The card's url is an MCP streamable-HTTP endpoint (initialize returns serverInfo tarx 3.18.0). An A2A client sending message/send or tasks/get there gets JSON-RPC -32601 Method not found. The card is therefore a discovery document for an MCP server dressed in A2A shape, not an A2A service — an agent that trusts the grade alone will fail on first contact. - field: preferredTransport / supportedInterfaces / additionalInterfaces observed: absent note: 0.3.0-shaped card without a transport declaration; a 1.0.0 reader finds no supportedInterfaces[].protocolBinding. - field: security / securitySchemes observed: security is an empty array, securitySchemes absent note: >- No authentication is declared, yet the MCP server behind the url gates private tools on OAuth (RFC 8414 + RFC 9728 metadata on mcp.tarx.com, scopes public/user/chatgpt_private_memory). The card under-declares the auth model. - field: skills[].examples observed: present on 1 of 4 skills (cairn) note: Optional per-skill field; soul, need-computer and need-reserve carry none. - field: skills[3] need-reserve observed: description says "Not generally live" note: A published skill the card itself marks as unavailable. - field: version observed: 0.1.0 note: Card version; the MCP server it points at reports 3.18.0 and mcp.json reports 3.17.0. surface_relationship: note: >- TARX publishes one agent endpoint (MCP at mcp.tarx.com/mcp) and three discovery documents that point at it — this A2A card, /.well-known/mcp.json and /.well-known/ai-plugin.json on the MCP host — plus a prose "cairn" (we.txt, skill.md, courier.md) that tells visiting agents to register a Soul through plain REST on tarx.com/api. There is no OpenAPI for any of it.