x402 Preflight
Check an x402 seller before you pay it. Probes the endpoint now, checks that its payment can actually succeed (token EIP-712 domain, payTo), and adds its 30-day uptime from our monitor of paid Bazaar listings, how many distinct buyers paid it, and how its price compares with similar listings, with cheaper well-used alternatives. Returns a verdict (ok, caution, avoid) with the reasons.
The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.
Live 402 challenge
Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.
{
"error": "Payment required",
"request": {
"url": "https URL of the x402 endpoint you are about to pay",
"method": "GET or POST",
"max_price_usd": "optional limit"
},
"networks": [
"eip155:8453"
],
"how_to_pay": "The payment options are base64 JSON in the PAYMENT-REQUIRED response header. Pay $0.002 in USDC with an x402 client (for example @x402/fetch)."
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
Pay 0.002 USDC on Base to 0xe6f7…3c3f8. The signed payment is good for 5 minutes.
- Paid to
- 0xe6f7…3c3f8
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 2000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xe6f7508ab572a4dc9c7486ea017b100d83f3c3f8",
"amount": "2000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"url": "https://api.example/v1/search",
"method": "GET",
"max_price_usd": 0.05
}
},
"output": {
"type": "json",
"example": {
"now": {
"ms": 180,
"method": "GET",
"pay_to": "0x...",
"status": 402,
"networks": [
"eip155:8453"
],
"price_usd": 0.01,
"x402_version": 2
},
"url": "https://api.example/v1/search",
"bazaar": {
"listed": true,
"calls_30d": 3,
"payers_30d": 1,
"last_called_at": "2026-10-20T08:00:00Z"
},
"market": {
"query": "Web search for agents",
"alternatives": [
{
"resource": "https://other.example/search",
"price_usd": 0.002,
"payers_30d": 40,
"uptime_30d": 1
}
],
"median_price_usd": 0.005,
"similar_listings": 20
},
"history": {
"probes": 120,
"uptime": 0.99,
"median_ms": 210,
"last_ok_at": "2026-10-25T00:00:00Z",
"last_failure": null,
"price_changes": [],
"monitored_since": "2026-10-01T00:00:00Z"
},
"reasons": [
"Only 1 distinct buyer paid it in the last 30 days."
],
"verdict": "caution"
}
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method"
],
"properties": {
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"type": "object",
"required": [
"url"
],
"properties": {
"url": {
"type": "string",
"maxLength": 2048,
"description": "https URL of the x402 endpoint you are about to pay"
},
"method": {
"enum": [
"GET",
"POST"
],
"type": "string",
"description": "method you will call it with (default GET)"
},
"max_price_usd": {
"type": "number",
"description": "the most you are willing to pay per call; a higher price gives the verdict avoid"
}
}
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"required": [
"url",
"verdict",
"reasons"
],
"properties": {
"now": {
"type": "object",
"description": "the live probe: method, status, latency, protocol version, price, networks, payTo"
},
"url": {
"type": "string"
},
"bazaar": {
"type": "object",
"description": "the CDP Bazaar listing: distinct payers and calls in 30 days"
},
"market": {
"type": "object",
"description": "median price of similar listings and cheaper alternatives with payers and uptime"
},
"history": {
"type": "object",
"description": "our monitor's 30-day record: probes, uptime (0-1), median latency, last failure, price changes; null when not monitored"
},
"reasons": {
"type": "array",
"description": "why the verdict is not ok; empty when it is"
},
"verdict": {
"enum": [
"ok",
"caution",
"avoid"
],
"type": "string"
}
}
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-10-24 18:17Z
- Last indexed by Roundhouse
- 2026-10-26 17:20Z
- Last enriched (probe, favicon, geo)
- 2026-10-24 23:16Z
- x402 version
- 2
- Max timeout
- 300s
- Liveness probe
- HTTP 402
Hand this page to an agent
Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.
GET api.roundhouseai.io/v0/endpoints
No per-endpoint history for this service yet, so this is payments indexed to its PROVIDER's wallet over 30 days. Verified volume counts only settlements with an on-chain EIP-3009 marker.
Show the promptHide the prompt
Using Roundhouse, look up the x402 service x402 Preflight and tell me whether it is worth paying: what a call costs, whether the endpoint answered when last probed, and what its payment record actually shows. curl -s 'https://api.roundhouseai.io/v0/endpoints?q=x402%20Preflight' curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>' Then call it: read the price from the live 402 at https://f0r6bcvc1s410hk1.68r.lambda-web.us-east-1.on.aws/v1/preflight, never from a cached figure, and pay with an x402 client. The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except /v0/unified* and /v0/endpoints. Either pay over x402 (mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.