SendCheck
Pre-send address verification for EVM transfers, x402 paid, USDC on Base, no API key. Two verified paid routes: POST /check at $0.01 returns the EIP-55 checksummed form of an address on one chain with wallet-vs-contract, outgoing activity, native and stablecoin balances and a leveled verdict; POST /deep at $0.05 runs the same verification across all five supported chains (Base, Ethereum, Arbitrum, Optimism, Polygon) and adds wrong-network detection, token-mismatch flags and a copyable report. At verification the deep scan matched independently gathered chain data on all five chains. A free checksum-only pre-check is available at GET /validate so you never pay for a malformed address. Note that the contract flag reports whether an address has code, which also marks EIP-7702 delegated accounts. Base only.
2 of 2 routes settlement-verified · $0.01–$0.05 USDC/request · 2 endpoints / 2 tools · Verification · base network · x402 protocol
Verified routes
Other routes are unverified.
Networks: Base (settlement-verified)
Discovery is free. Agents search the catalogue here. Payment happens on the listing 402, not on PayAPI.
url https://payapi.market/mcpAbout this API
SendCheck is listed in the Verification category with pricing at $0.01–$0.05 USDC/request. 2 routes have been settlement-verified by PayAPI Market on 2026-09-14. View receipt on Basescan.
Payments settle on base in USDC via the x402 protocol. AI agents discover this API through the PayAPI Market MCP server and pay per request without API keys or accounts.
This API exposes 2 endpoints.
How to call this API
Every protected route returns HTTP 402 with x402 payment requirements. An agent pays the stated USDC amount on Base and retries with the payment header. No API keys, no accounts. Browse the marketplace or list your own API.
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By Pennyforge