# lab-leads > Agent-payable newly-funded-lab lead feed — institutions that just won an NIH award, with grant size, likely equipment category, and the 0–6mo spend window. A funded grant = a lab about to buy. 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://lableads.dropwatchhq.com/mcp (transport: streamable-http; call tools/list then tools/call) ## Paid tools (x402 pay-per-call, USDC on base) - `lab_lead_feed` — $0.05 USDC/call. Full enriched newly-funded-lab lead set (NIH onset trigger). ## Free tools - `list_categories` — free. Equipment categories we classify funded labs into. - `newly_funded_labs` — free. Preview of labs that just won an NIH award (capped, signal-only). ## How an agent pays (x402 over MCP) 1. POST https://lableads.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 ## Spec Implements x402 v1 (scheme "exact", EVM EIP-3009). See https://github.com/coinbase/x402 and https://docs.x402.org . Machine descriptor: https://lableads.dropwatchhq.com/.well-known/x402