Echo service for x402 protocol research
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.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
228 msmedian answer time
$0.001listed price per call
n/aprice it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://x402-echo-service.onrender.com/echo
| Category | Search and research |
|---|---|
| Provider host | x402-echo-service.onrender.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 10 from 7 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | 228 ms |
Example input (from the provider)
{
"body": {
"message": "hello world"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"message": {
"description": "Text to echo back.",
"maxLength": 4096,
"minLength": 1,
"type": "string"
}
},
"required": [
"message"
],
"type": "object"
},
"bodyType": {
"enum": [
"json"
]
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http"
}
},
"required": [
"type",
"bodyType",
"body",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"echo": {
"type": "string"
},
"sha256": {
"type": "string"
},
"timestamp": {
"format": "date-time",
"type": "string"
}
},
"required": [
"echo",
"sha256",
"timestamp"
],
"type": "object"
},
"type": {
"const": "json"
}
},
"required": [
"type",
"example"
],
"type": "object"
}
},
"required": [
"input",
"output"
],
"type": "object"
}