mcpfax_preflight_check

com.mcpscores/agent-reliability-scores · Verify this server

Check that an endpoint is live and that its terms have not changed, BEFORE you send it an expensive request. WHEN THIS PAYS FOR ITSELF: a $15 call with a 2% failure rate carries an expected loss of $0.30, so a $0.002 check is a 150x return. WHEN IT DOES NOT: before a $0.001 data lookup the same check is a 2x loss. Buy it before a consequential call — expensive inference, a purchase, a state-changing action — and not before a cheap one. Returns two halves. LIVE: one unpaid bounded probe (~2.2s cap) giving reachability, HTTP status, latency, whether an MCP server still answers initialize, and the price and payTo it is serving right now. HISTORICAL: reliability over our OBSERVED window (stated in days, never implied), payTo changes, price changes, tool-schema changes, first-seen date, and credit grade or an honest not-rated. Supply expected_price, expected_payto or expected_schema_hash and each is compared with old to new and the date we first observed the change. The verdict is ALLOW, WARN or UNKNOWN and is ADVISORY: it reports evidence, it is not a warranty, an audit, or a promise your call will succeed. UNKNOWN is a real answer and is returned whenever the evidence does not support the other two. If we have never observed the target AND cannot reach it, you get UNKNOWN and are charged nothing. Otherwise $0.002 USDC per call via x402 on Base.