# agent-tools.cloud

> Open, agent-readable discovery directory of x402 paid services, MCP servers
> and A2A agents. Crawled, health-checked and safety-scanned. Free to search
> and use, no signup, no API key. We are a catalogue only — we do not host,
> operate, broker or take payment for listed third-party services.

## Use it programmatically

- Unified search: GET /api/v1/search?q=...
- MCP servers: GET /api/v1/mcp/search?q=...  | details: /api/v1/mcp/servers/{slug}
- A2A agents:  GET /api/v1/a2a/search?q=...  | details: /api/v1/a2a/agents/{slug}
- x402 services: GET /api/v1/services/{slug}
  (price_min/price_max span every resource the origin advertises; each
  call.resource_samples[] entry has its own price_usd and accepts[] -- use
  those, not the headline range, to price a specific endpoint)
- LLM-ranked recommendation: GET /api/v1/ask?q=...
- Directory stats: GET /api/v1/stats
- OpenAPI: /openapi.json

## MCP discovery endpoint

- Streamable-HTTP MCP server: https://agent-tools.cloud/mcp-discovery/
  Tools: search, get, search_mcp_servers, get_mcp_server, search_a2a_agents,
  search_resources, ask_services, list_categories, stats, scan_mcp_safety,
  register, prepare_paid_verification, execute_paid_verification,
  get_paid_verification.

## Sponsored paid verification (x402)

Pay a listed x402 service once from your own wallet; we call it once and
publish the result. Funds go straight to the service's payTo (EIP-3009,
Base USDC, <= $1). We never hold funds or sign for you. GET, or POST with the
listing's public JSON probe_body (<= 16 KiB).

HTTP:
1. POST /api/v1/keys -> api_key (no signup). Send Authorization: Bearer <api_key>.
2. POST /api/v1/services/{slug}/paid-verifications {"payer": "0x..."} -> id, typed_data
3. Sign typed_data with the payer wallet (eth_signTypedData_v4).
4. POST /api/v1/paid-verifications/{id}/execute {"signature": "0x..."} -> status, score, tx_hash
5. GET /api/v1/paid-verifications/{id}

MCP (same flow; API key as header or api_key argument):
prepare_paid_verification(slug, payer) -> execute_paid_verification(id, signature)
-> get_paid_verification(id)

Price and recipient are re-checked before paying; the call is never retried.
settled requires matching Base-USDC AuthorizationUsed and Transfer events.
Results (failures included) are public for 30 days in GET /api/v1/services/{slug}.
Evidence is hidden if the listing changes. Signatures and response bodies are not stored.

## Discovery manifests

- /.well-known/mcp.json
- /.well-known/agent-tools.json
- /.well-known/agent-card.json
- /.well-known/x402
- /sitemap.xml

## Notes for agents

- All search/read endpoints are free and unauthenticated.
- Listings include a heuristic safety verdict (malware / prompt-injection /
  tool-poisoning advisory) — advisory only, verify before connecting.
- Terms: /terms  ·  Privacy: /privacy  ·  Contact: contact@agent-tools.cloud