Three free tools from the 402 Clinic for x402 buyers on Base. No payment, no signup, no API key.
Your payment settled (or failed) and the call still did not work? Paste the transaction hash. The clinic reads the real receipt on Base and tells you which one it was: tx not found · tx failed on-chain · not a USDC transfer · wrong asset · wrong recipient · wrong amount · valid payment — plus the correct retry accepts (asset, network, payTo, amount) for the endpoint you claimed.
curl -s -X POST https://api.mekongtradeintel.com/clinic/diagnose-tx \
-H 'Content-Type: application/json' \
-d '{"tx_hash":"0xYOUR_TX_HASH","endpoint":"tokenprice"}'
Omit endpoint to diagnose without a price check; the response then guesses which endpoints match the paid amount.
Price a basket of calls before spending anything. Live unit prices — the same source as the clinic code generator — with line totals, a grand total, and how far a $1.00 credit pack goes. It is a pure calculation: it calls nothing and charges nothing.
curl -s -X POST https://api.mekongtradeintel.com/clinic/estimate \
-H 'Content-Type: application/json' \
-d '{"calls":[{"endpoint":"brief","count":20},{"endpoint":"tokenprice","count":500}]}'
Register your payer wallet, a monthly USDC cap, and a webhook. Month-to-date spend is computed from this host's fleet paid-call logs (Contabo-hosted endpoints; IH-hosted logs are not counted — the response says so). When a check runs and you have crossed 80% or 100% of the cap, one JSON alert per threshold per month is POSTed to your webhook.
# subscribe
curl -s -X POST https://api.mekongtradeintel.com/clinic/spendalert/subscribe \
-H 'Content-Type: application/json' \
-d '{"payer":"0xYOUR_WALLET","monthly_cap_usd":25,"webhook_url":"https://your-agent.example/hook"}'
# month-to-date status
curl -s 'https://api.mekongtradeintel.com/clinic/spendalert/status?payer=0xYOUR_WALLET'
# evaluate thresholds and fire any due alerts
curl -s -X POST https://api.mekongtradeintel.com/clinic/spendalert/check \
-H 'Content-Type: application/json' -d '{"payer":"0xYOUR_WALLET"}'
Seller wallet (payTo): 0x198f3895551B309fF5C5F59e690FB0823d10EA93 · Network: Base (eip155:8453) · Asset: USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913. Contact: [email protected]. See also the migration kit and data-residency statement.