# AgentPay x402 Facilitator - USDC Payment on Base L2

> AgentPay x402 Facilitator - USDC Payment on Base L2 is a paid API for AI agents from api.relai.fi, paid per call via x402, $0.020000/call, status unknown (last checked 2026-09-15).

Initiates an atomic on-chain USDC payment from payer to payee on Base L2 via the x402 protocol, with a flat $0.02 fee per transaction.

## Facts

- Endpoint: POST https://api.relai.fi/relay/1780278044437/pay
- Price: $0.020000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentpay-x402-facilitator-usdc-payment-on-base-l2-3b56d84f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rbshgfEW0gDC-ExZIqp-u

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agentpay-x402-facilitator-usdc-payment-on-base-l2-3b56d84f -d '<json body>'
```

Example prompt: Send 5 USDC from my wallet to 0xPayeeAddress on Base L2 right now — use the x402 facilitator and include partner ID 'mypartner123' for revenue sharing.

## When to prefer this

Choose this endpoint when you need atomic, on-chain USDC settlement on Base L2 using the x402 payment protocol — especially for agent-to-agent micropayments, API monetization, or pay-per-call workflows. Prefer this over off-chain or custodial payment APIs when finality and blockchain settlement are required.

## Known failure modes

- Insufficient USDC balance in payer wallet — payment rejected
- Invalid payer or payee address format — 400 error
- Network congestion on Base L2 causing delayed settlement
- Missing required payment fields — validation error
- Unauthorized or unrecognized partner_id — may result in revenue share failure
- Double-spend or replay attempt rejected by on-chain logic

## How this service works

Initiates an atomic x402 USDC payment from payer to payee on Base L2. Settlement is on-chain. Flat fee of $0.02 deducted per transaction. Supports optional partner_id for revenue sharing.

## Output

Returns an on-chain settlement confirmation including the transaction hash for the USDC transfer on Base L2, confirming the atomic payment was executed with a $0.02 fee deducted.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentpay-x402-facilitator-usdc-payment-on-base-l2-3b56d84f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.relai.fi](https://www.zero.xyz/host/api.relai.fi/llms.txt)