Cheapest possible Base-mainnet x402 conformance call
Cheapest possible Base-mainnet x402 conformance call: settle $0.001 of USDC and receive payer identity, request echo and receipt. Built for agents testing wallets, Payment-Signature, facilitators and settlement. Try GET /x402-echo/sample.
Answeringour last check, 2026-09-28
1 of 1checks answered this week
1122 msmedian answer time
$0.001listed price per call
$0.001price 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.agentindex.world/x402-echo
| Category | Everything else |
|---|---|
| Provider host | x402.agentindex.world |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-28 | valid payment request | 402 | $0.001 | 1122 ms |
Example input (from the provider)
{
"body": {
"message": "hello agent"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"message": {
"description": "Optional test message to echo after successful settlement.",
"type": "string"
}
},
"required": []
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"network": {
"type": "string"
},
"ok": {
"type": "boolean"
},
"payer": {
"type": [
"string",
"null"
]
},
"price_atomic_usdc": {
"type": "string"
},
"price_usdc": {
"type": "number"
},
"purpose": {
"type": "string"
},
"request": {
"type": "object"
},
"x402_receipt": {
"type": "object"
}
},
"required": [
"ok",
"purpose",
"network",
"price_usdc",
"price_atomic_usdc",
"request"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}