Non-custodial · Protocol-agnostic

The Universal Payment Layer for AI Agents

XyncPay translates payment instructions between x402, MPP, and AP2 protocols so any AI agent can pay any service — regardless of which protocol either party uses. One integration, every protocol.

View the APIHow It Works

How It Works

Four steps. Zero custody.

01

Agent submits request

An AI agent sends a payment request specifying the source protocol, target protocol, amount, and recipient.

02

XyncPay translates

The translation engine normalizes the request, calculates the fee, and builds an unsigned transaction targeting the fee-split contract.

03

Agent signs

XyncPay returns the unsigned transaction. The agent signs with its own private key and submits to the blockchain. XyncPay never touches funds.

04

Settlement confirmed

The smart contract atomically splits the payment: net amount to the payee, fee to XyncPay. Sub-second finality on Base.

Supported Protocols

Every protocol. One integration.

XyncPay translates between all major AI agent payment protocols launched in 2025-2026.

x402

Coinbase

Full

HTTP 402-based payment protocol for pay-per-request APIs. EIP-3009 authorization with ERC-20 token transfers on Base.

MPP

Stripe / Tempo

Full

Session-based micropayment streaming protocol. Spending caps, rate limits, and continuous payment flows for agent workflows.

AP2

Google

Stub

Cryptographically-signed mandate protocol. Inbound parsing and validation active; outbound routes through x402 or MPP at launch.

Fee Structure

Transparent from day one

1%

per transaction

$0.001

floor

$1.00

cap

On-chain

atomic split

ProviderRate$100 txn
XyncPay1.0%$1.00
Stripe Stablecoins1.5%$1.50
Card Processing2.9% + $0.30$3.20

Fee rate is owner-configurable via the smart contract without redeployment.

For Developers

One API call. Any protocol pair.

Submit a payment request, receive an unsigned transaction. Your agent signs and submits. XyncPay never sees your private key.

Request

POST/v1/payments/translate
curl -X POST https://api.xyncpay.com/v1/payments/translate \
  -H "Content-Type: application/json" \
  -H "X-Wallet-Address: 0xYourAgent..." \
  -H "X-Wallet-Signature: 0xSig..." \
  -d '{
    "sourceProtocol": "x402",
    "targetProtocol": "mpp",
    "payeeAddress": "0xService...",
    "amount": "1000000",
    "currency": "USDC",
    "chain": "base"
  }'

Response

201application/json
{
  "data": {
    "paymentId": "pay-a1b2c3d4...",
    "unsignedTransaction": {
      "chainId": 8453,
      "to": "0xFeeSplit...",
      "data": "0x...",
      "value": "0",
      "gasLimit": "150000"
    }
  }
}

Agent signs the transaction with its own private key via ethers.js or @solana/web3.js, then submits to the blockchain. The fee-split smart contract handles the rest atomically.