Browse or keyword-search the verified catalog of pay-per-call (x402) agent services. Use it when you don't know the task name or want to see what exists; use lookup to rank endpoints for a known task at a max price, and get_service for one id's full record. Read-only. No auth or API key; free, no quota or per-client limit: it only reads the catalog snapshot (bundled catalog.json in the local server, the published catalog.json on remote /mcp). Returns {count, results, generated_at, note, methodology_url}; results are in catalog order, ungraded, each with id, name, category, endpoint, advertised_price_usd, page_url and latest (checked_at, reachable, http_status, latency_ms, quoted_price_usd, price_matches_listing, charged_price_usd, delivered_valid, raw_log_url). No match: count 0, empty results. A non-numeric max_price_usd or limit returns an error.

Fetch the complete catalog record for one known service id (e.g. from search_catalog or lookup results). Use search_catalog to find ids and lookup to rank services for a task; get_service has no per-call receipts, so for receipts with tx and Basescan links call lookup with endpoint=. Read-only. No auth or API key; free, no quota (reads the same catalog snapshot as search_catalog). Returns the record as published: id, name, provider, category, description, endpoint, advertised_price (USD, atomic, asset, network), sample_request, tasks, quality_test (known-answer test, facts_only flag and reason), paid_receipts (count), latest (full last check incl. x402_challenge, error, raw_log_url), history_summary and page_url. Unknown or missing id: error "no service with id ...".

Rank x402 endpoints for a known task at or under a price: "which endpoint should I pay for task X at <= $Y?". Prefer it over search_catalog (keyword browsing, unranked) and get_service (one id's raw record). No auth or API key. Calls the hosted lookup service as client=vc-mcp; all MCP users share that client's 5 free lookups per UTC day (reset 00:00 UTC), after which the tool returns an error reporting the HTTP 402 ($0.02 USDC on Base via x402) and never pays. Returns results sorted by known-answer pass_rate over the last n paid calls, then price, each with price_usd, pass_rate, last_check_at, last_check, stale and receipts (time, tx, basescan_url, charged_usd, delivered, quality); seller-broken services come unsorted under facts_only. No match: empty results, matched 0. Needs task or endpoint; invalid params return an error. Payment never changes results.