# x402 Echo Preflight Oracle

> x402 Echo Preflight Oracle is a paid API for AI agents from home.chrz.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Echoes back a client payload alongside live x402 payment requirements and authorization proof for Solana/Base mainnet agent wallet preflight checks.

## Facts

- Endpoint: POST https://home.chrz.dev/agent-dust/v1/agent/x402-echo
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-echo-preflight-oracle-875516d2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zVxAe_n8hrldto7H0MSAv

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 x402-echo-preflight-oracle-875516d2 -d '<json body>'
```

Example prompt: Run a preflight x402 echo test with my agent wallet — send a note payload and confirm that the payment authorization and USDC requirements come back correctly for Base mainnet.

## When to prefer this

Choose this endpoint when you need to preflight-test an AI agent's x402 micropayment capability against a real mainnet endpoint before integrating with production paid APIs. It is the canonical echo/smoke-test for x402 protocol compliance, particularly for agents using USDC on Base (eip155:8453). Prefer this over mock or testnet endpoints when you need to validate real authorization payloads and payment requirement structures.

## Known failure modes

- Missing or invalid x402 payment header returns 402 Payment Required with updated payment requirements
- Insufficient USDC balance causes payment authorization failure
- Wrong network (non-Base) payment rejected
- Malformed JSON body causes 400 Bad Request
- Expired payment authorization token causes re-authentication requirement

## How this service works

x402-paid Solana mainnet wallet preflight oracle for agents.

## Output

Returns a JSON object confirming the echo (ok: true), the original client payload echoed back, a full x402 version 2 payment_payload with authorization string, and payment_requirements specifying the USDC asset address on Base (eip155:8453), the required amount (10000 units = $0.01 USDC), and the network identifier.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "echo": {
   "note": "client test"
  },
  "payment_payload": {
   "payload": {
    "authorization": "..."
   },
   "x402Version": 2
  },
  "payment_requirements": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "amount": "10000",
   "network": "eip155:8453"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-echo-preflight-oracle-875516d2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from home.chrz.dev](https://www.zero.xyz/host/home.chrz.dev/llms.txt)