x402 Payment Protocol — ATXP

Discovered: 2026-06-25 Status: Works in theory, needs funded wallet to execute

Что это

ATXP использует x402 протокол для оплаты MCP вызовов. Когда MCP tool стоит >$0 (search, image, video, music, paas, phone_send_sms, email_send), ответ содержит 402 + payment URL.

Payment Request Format

GET https://auth.atxp.ai/payment-request/{id}
{
  "id": "gbsUEXkZS1NkjTydo0bzS",
  "sourceAccountId": "atxp:atxp_acct_1uahidiHVCb5oCE93ashk",
  "destinationAccountId": "atxp:atxp_acct_DBejkLi5OO39M02Wo4mFF",
  "options": [
    {"network": "atxp", "currency": "USDC", "address": "atxp_acct_DBejkLi5OO39M02Wo4mFF", "amount": "0.001"},
    {"network": "base", "currency": "USDC", "address": "0x10C140022927429AFb5F7779F4BC5495da8C1e24", "amount": "0.001"},
    {"network": "base", "currency": "USDC", "address": "0x13b5275D8300290E08923dc7F6Cbcff1Be26eF6F", "amount": "0.001"},
    {"network": "world", "currency": "USDC", "address": "0x10C140022927429AFb5F7779F4BC5495da8C1e24", "amount": "0.001"},
    {"network": "solana", "currency": "USDC", "address": "BJGdsDXJFy63eCAnX3UmGfShp8BuqbtkTfcamyRGr7VQ", "amount": "0.001"},
    {"network": "polygon", "currency": "USDC", "address": "0x10C140022927429AFb5F7779F4BC5495da8C1e24", "amount": "0.001"}
  ],
  "payeeName": "PaaS",
  "resource": "example-resource",
  "createdAt": "2026-06-25T00:08:34.317Z",
  "iss": "auth.atxp.ai"
}

Networks & Addresses

Network	Address	Note
atxp	atxp_acct_DBejkLi5OO39M02Wo4mFF	Internal — uses $10 ATXP balance
base	0x10C140022927429AFb5F7779F4BC5495da8C1e24	Main ATXP EOA (8241 USDC)
base	0x13b5275D8300290E08923dc7F6Cbcff1Be26eF6F	ATXP proxy contract
world	0x10C140022927429AFb5F7779F4BC5495da8C1e24	World Chain
solana	BJGdsDXJFy63eCAnX3UmGfShp8BuqbtkTfcamyRGr7VQ	Solana USDC
polygon	0x10C140022927429AFb5F7779F4BC5495da8C1e24	Polygon USDC

How to Pay (per x402 spec)

Make request to MCP → get 402 + payment URL
Send USDC to one of the addresses in correct amount

Retry request with header:

X-PAYMENT: {"x402Version":1,"scheme":"exact","network":"base","payload":{"transaction":"0x..."}}

Current Status

❌ Payment endpoint /payment-request/{id}/pay returns 404
❌ X-PAYMENT header doesn't unlock the resource (still asks for new payment)
✅ atxp internal network option exists but unclear how to trigger

Possible Exploits

Send USDC to 0x10C140... (or 0x13b527...) from any wallet with USDC on Base
- Minimum: 0.001 USDC
- This would unlock ALL paid MCP tools
- Need private key for sending wallet
Internal atxp payment — if it works through /fund or /pay, would let $10 accounts pay $0.001 from their balance (but they're restricted on LLM Gateway)
Faucet/USDC grant — find a free USDC faucet on Base testnet or mainnet

Alchemy Key (read-only)

Found in accounts.atxp.ai HTML:

REACT_APP_BASE_RPC: "https://base-mainnet.g.alchemy.com/v2/ENYtQe49qSTmOeat11aTJ"

Can monitor balances and transactions, but CANNOT send (no private key).

Open Questions

How does atxp network payment work programmatically? Need endpoint or protocol details
Does paying unlock LLM Gateway restricted, or just paid MCP tools?
Can $10 balance be used via internal atxp network even when LLM is restricted?

3.4 KiB Raw Blame History