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x402 Research Echo
x402
x402 Research Echo is a paid API for AI agents from x402-echo-service.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).
Echoes a submitted message back with its SHA-256 digest and a server timestamp, used for x402 protocol conformance and discovery-layer research.
Price / call$0.001
Success—
StatusUnknown
How this service works
Echo service for x402 protocol research. POST a JSON body with a "message" string; the response returns the message, its SHA-256 digest and a server timestamp. Payment is live: $0.001 USDC on Base is verified and settled via the Coinbase CDP facilitator, so callers ARE charged. The response is computed before settlement, and the settlement tx hash is returned in the body and in PAYMENT-RESPONSE.
Output
A JSON object containing three fields: 'echo' (the original message string), 'sha256' (the SHA-256 hex digest of the message), and 'timestamp' (an ISO 8601 UTC datetime string from the server at time of processing). No payment is actually settled despite the x402 payment advertisement.
Example use cases
x402 protocol conformance testing
“Send the message 'conformance test payload' to the x402 echo service and show me the SHA-256 digest and timestamp it returns so I can confirm the protocol response format is correct.”
Message integrity verification via echo
“I need to verify the SHA-256 hash of the string 'my important payload' — can you run it through the x402 echo endpoint and give me the digest?”
x402 discovery layer latency probe
“Hit the x402 research echo endpoint with the message 'ping' and tell me the server timestamp so I can measure round-trip timing for my research.”
Technical details
Endpoint
POSThttps://x402-echo-service.onrender.com/echoWhen to prefer
Choose this endpoint when you need to test x402 protocol conformance, probe the x402 discovery layer, or verify SHA-256 hashing behavior in a safe research context where no real payment settlement occurs. It is purpose-built for security research and protocol testing, not for production message hashing or real payment flows.
Side effects
- Empty or missing 'message' field returns a validation error
- Message exceeding 4096 characters is rejected
- Service may be unavailable if the Render.com free-tier instance is sleeping (cold start delay)
- Malformed JSON body returns a parse error
- Network timeout if the instance is spinning up from idle
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| message | string | Text to echo back. |
Output
Schema · Response
{
"type": "json",
"example": {
"echo": "hello world",
"sha256": "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
"timestamp": "2026-08-18T12:00:00.000Z"
}
}Tags
x402
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