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

• POST /check · $0.01 · 2026-09-14 · receipt
• POST /deep · $0.05 · 2026-09-15 · receipt

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/mcp

Listing facts

Provider

Pennyforge

Hosted at

api.pennyforge.org

Category

Verification

Price

$0.01 to $0.05 USDC per request

Endpoints

2

MCP tools

2

Payment networks

Base

Settlement-verified

2 routes, last checked 2026-09-15

Listed on PayAPI Market

2026-09-14

Try SendCheck

Call a verified route without paying first. The server should answer HTTP 402 Payment Required with the price, the USDC asset, the network and the wallet to pay. An x402 client pays that amount on Base and retries with the payment header.

curl -i -X POST "https://api.pennyforge.org/check"
curl -i -X POST "https://api.pennyforge.org/deep"

About 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. 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.

Questions about this API

What does SendCheck do?

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. It is provided by Pennyforge.

How much does SendCheck cost?

SendCheck is priced at $0.01 to $0.05 USDC per request, paid per call with no subscription. PayAPI Market paid 0.01 USDC for one call to /check when it verified the listing. The exact amount for each call is in the HTTP 402 response before any money moves.

Do I need an API key or account to use SendCheck?

No. SendCheck uses the x402 protocol, so an agent pays per request in USDC on Base and gets the response, with no API key, account or signup.

Has SendCheck been verified?

Yes, 2 routes. PayAPI Market paid for a real call from its own wallet, received real data back and recorded the USDC settlement on-chain, most recently on 2026-09-15.

How does an AI agent find SendCheck?

Through the free PayAPI Market MCP server at https://payapi.market/mcp, using search_apis or get_api, or over plain HTTP at https://payapi.market/agent/search. Discovery is free; the agent pays the provider directly on the listing's own 402.

More Verification APIs · Browse the marketplace · List your own API

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By Pennyforge