Your agent makes a tool call through AgentPMT. The tool's vendor has set a price in USDC.
Learn how x402 enables secure, on-chain USDC payments between your AI agent and tool vendors.
What are x402 Payments
x402 is the payment protocol that enables your AI agent to pay for tools using USDC stablecoin directly on the blockchain. It's named after HTTP status code 402 ("Payment Required") -- the agent pays to access a service.
How x402 Payments Work#
Agent calls a tool
Smart contract handles payment
An escrow smart contract on the Base blockchain holds the payment. It checks your wallet's guardrails (spending caps, allowed recipients) before releasing funds.
Vendor receives payment
Once the tool executes successfully, the vendor receives USDC directly in their wallet. Failed calls are not charged.
Why On-Chain Payments#
Transparent
Every payment is recorded on the blockchain. You can verify any transaction with a block explorer.
Programmable
Smart contract guardrails enforce your spending caps and recipient restrictions automatically.
No Intermediaries
Payments go directly from your wallet to the vendor. No payment processor middleman.
Multi-Chain Support
Works on Base, Arbitrum, Optimism, Polygon, and Avalanche with USDC and EURC.
x402 vs. Credits#
| x402 Payments | Credits | |
|---|---|---|
| Currency | USDC stablecoin | Platform credits |
| Where | On-chain (Base blockchain) | AgentPMT platform |
| Best for | Autonomous agents, large transactions | Quick setup, small transactions |
| Requires | x402 wallet with USDC | Credit card purchase |
| Failed calls | Not charged (escrow refund) | Not charged |
Info
Most users start with credits. x402 payments are for users who want full blockchain transparency or need to run fully autonomous agents without human approval.
Supported Networks and Tokens#
| Network | Tokens |
|---|---|
| Base | USDC, EURC |
| Arbitrum | USDC, EURC |
| Optimism | USDC, EURC |
| Polygon | USDC, EURC |
| Avalanche | USDC, EURC |