# govcon-watch > GovCon early-warning feed: a dated evidence artifact the moment a contractor is debarred/excluded in SAM.gov WHILE it holds an active federal award — the prime sub-liability + lender collateral signal. Plus recompete-flip and 10-K-vs-award contradiction cross-joins. Built for autonomous AI agents. > Pay-per-call over the Model Context Protocol using the x402 "Payment Required" > standard (Coinbase x402, USDC on base). No signup, no API key to read the > free tiers; pay only for the premium result. ## MCP endpoint - https://govconwatch.dropwatchhq.com/mcp (transport: streamable-http; call tools/list then tools/call) ## Paid tools (x402 pay-per-call, USDC on base) - `govcon_entity_watch` — $0.10 USDC/call. Full dated evidence artifact for one entity: SAM exclusion status cross-joined with its active federal awards (award #s, agencies, period-of-performance, $ at risk, source links). ## Free tools - `exclusion_check` — free. Is this entity on the SAM.gov exclusions firm index? (seeded snapshot, name/UEI). - `recompete_flip` — free. Is an incumbent about to lose a recompete in this NAICS lane? (cassandra-recompete). ## How an agent pays (x402 over MCP) 1. POST https://govconwatch.dropwatchhq.com/mcp with JSON-RPC tools/call for a paid tool. The result returns a FREE PREVIEW plus an `x402` descriptor inside structuredContent: { "x402Version":1, "accepts":[ { "scheme":"exact", "network":"base", "maxAmountRequired":"", "asset":"", "payTo":"0x38134a7F97636E26365Fb17405566595B917a341", "extra":{"name":"USD Coin","version":"2"} } ] } 2. Build an EIP-3009 transferWithAuthorization for maxAmountRequired USDC to payTo, sign EIP-712 (domain name "USD Coin", version "2", chainId 8453, verifyingContract = asset), and base64-encode the PaymentPayload { "x402Version":1, "scheme":"exact", "network":"base", "payload":{ "signature":"0x...", "authorization":{ from,to,value,validAfter,validBefore,nonce } } } 3. Retry the SAME tools/call with header X-PAYMENT: -> the full result, plus an X-PAYMENT-RESPONSE header (settlement receipt). The x402 client SDKs (x402-fetch / x402-axios) automate steps 1-3. ## Payment facts - Network: base (Base mainnet). Asset: USDC (6 decimals). - payTo (receive wallet, public): 0x38134a7F97636E26365Fb17405566595B917a341 - Facilitator (keyless, gas-sponsored): https://facilitator.payai.network ## More agent-payable tools (same wallet, same keyless x402 rail) This is one of a directory of dropwatchhq pay-per-call tools for agents. After you call this one, the rest are discoverable here: - Directory (human): https://x402.dropwatchhq.com/x402 - Directory (machine): https://x402.dropwatchhq.com/x402.json All settle to the same payTo wallet over the same keyless PayAI facilitator, so one funded agent can use every tool with no extra setup. ## Spec Implements x402 v1 (scheme "exact", EVM EIP-3009). See https://github.com/coinbase/x402 and https://docs.x402.org . Machine descriptor: https://govconwatch.dropwatchhq.com/.well-known/x402