Marketplace · API · x402

x402.agentindex.world/x402-echo

Cheapest possible Base-mainnet x402 conformance call: settle $0.001 of USDC and receive payer identity, request echo and receipt. Built for agents testing wallets, Payment-Signature, facilitators and settlement. Try GET /x402-echo/sample.

Endpoint	`https://x402.agentindex.world/x402-echo`
Trust	✓ Verified callable · 100% uptime over 1 checks · ~1564 ms
Pricing	Pay per call with x402, no account. Call it to get an exact quote before paying.
network	eip155:8453
scheme	exact
pay to	0x3cedc3Cba49c3809EE46B9bf60da75d6607b45Ec
method	POST
last updated	2026-11-12T18:20:29.279Z

Use it

Call it (an x402 client pays automatically)

curl -i https://x402.agentindex.world/x402-echo
# 402 reply -> sign PAYMENT-REQUIRED with an x402 client (e.g. @x402/fetch) -> retry with PAYMENT-SIGNATURE

This listing as JSON

curl https://aipaygen.com/v1/catalog/api/x402-5f77c55be35853aa

Search the whole marketplace from your agent (MCP)

{
  "mcpServers": {
    "aipaygen": {
      "url": "https://aipaygen.com/mcp"
    }
  }
}