x4PayAPI Market

Signed attestation (ECDSA plus a post-quantum ML-DSA-65 companion) of on-chai...

Signed attestation (ECDSA plus a post-quantum ML-DSA-65 companion) of on-chain wallet conditions across 37 chains: token balance, NFT ownership, EAS, Farcaster, view calls, ratio rules, account code (plain key, EIP-7702 delegation, or contract), and agent standing (ERC-8004 registration, ERC-7710 delegation validity). A verifiable boolean, never raw balances or code. Up to 10 conditions per pay-per-call request. Pay in USDC on Base, Polygon, Arbitrum, Arc, or Solana.

1 route settlement-verified · $0.05 USDC/request · 1 endpoint · 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/mcp

About this API

Signed attestation (ECDSA plus a post-quantum ML-DSA-65 companion) of on-chai... is listed in the Verification category with pricing at $0.05 USDC/request. One route has been settlement-verified by PayAPI Market on 2026-10-21. 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 1 endpoint.

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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