x402 Endpoint Buyer Preflight
Verify and lint a third-party x402 endpoint without paying it. Probe the live HTTP 402 challenge, validate x402 v2 and Base payment requirements, and check exact Coinbase Bazaar and 402index listing evidence before a buyer authorizes payment.
SearchLiveeip155:8453Exactvia cdp
x402 endpoint verificationx402 preflightBuyer safetyPayment challengeBazaar
Calls · 30d
2↓ 18%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 21 snapshots so far.
$8.76
Verified settled volume
236 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0030
Listed price
As published in the catalog. Always read the live 402 before paying.
2
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-08-16 01:58Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x8647F7D7a1368a467Ad1FF757fBc2e7167973558The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.
Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Provider
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",
"accepts": [
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0x8647F7D7a1368a467Ad1FF757fBc2e7167973558",
"amount": "3000",
"scheme": "exact",
"network": "eip155:8453",
"mimeType": "application/json",
"resource": "https://ai-data-marketplace-1042299154756.us-central1.run.app/api/v1/x402_endpoint_preflight",
"maxAmountRequired": "3000",
"maxTimeoutSeconds": 300
}
],
"message": "This route accepts the x402 v2 PAYMENT-SIGNATURE flow on Base Mainnet. The legacy transaction-hash flow remains available for existing clients.",
"resource": {
"url": "https://ai-data-marketplace-1042299154756.us-central1.run.app/api/v1/x402_endpoint_preflight",
"tags": [
"x402 endpoint verification",
"x402 preflight",
"buyer safety",
"payment challenge",
"bazaar"
],
"iconUrl": "https://ai-data-marketplace-1042299154756.us-central1.run.app/favicon.svg",
"mimeType": "application/json",
"description": "Verify and lint a third-party x402 endpoint without paying it. Probe the live HTTP 402 challenge, validate x402 v2 and Base payment requirements, and check exact Coinbase Bazaar and 402index listing evidence before a buyer authorizes payment.",
"serviceName": "x402 Endpoint Buyer Preflight"
},
"extensions": {
"bazaar": {
"info": {
"input": {
"type": "http",
"queryParams": {
"url": "https://example.com/api/paid",
"method": "GET"
}
},
"output": {
"type": "json",
"example": {
"success": true,
"decision": "payment_challenge_is_structurally_ready",
"discovery": {
"coinbase_bazaar": {
"checked": true,
"exact_match_count": 1
}
},
"ready_for_payment": true,
"payment_requirements": []
}
}
},
"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",
"HEAD",
"DELETE"
],
"type": "string"
},
"queryParams": {
"type": "object",
"required": [
"url"
],
"properties": {
"url": {
"type": "string",
"description": "Public HTTP or HTTPS endpoint to inspect without paying."
},
"method": {
"type": "string",
"description": "GET, HEAD, or POST. Defaults to GET."
},
"request_body": {
"type": "object",
"description": "Optional JSON body for a POST probe. Payment credentials are never forwarded."
}
},
"additionalProperties": true
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"required": [
"success",
"ready_for_payment",
"decision",
"payment_requirements",
"discovery"
],
"properties": {
"success": {
"type": "boolean"
},
"decision": {
"type": "string"
},
"discovery": {
"type": "object",
"required": [
"coinbase_bazaar"
],
"properties": {
"coinbase_bazaar": {
"type": "object",
"required": [
"checked",
"exact_match_count"
],
"properties": {
"checked": {
"type": "boolean"
},
"exact_match_count": {
"type": "integer"
}
},
"additionalProperties": true
}
},
"additionalProperties": true
},
"ready_for_payment": {
"type": "boolean"
},
"payment_requirements": {
"type": "array",
"items": {}
}
},
"additionalProperties": true
}
}
}
}
}
}
},
"x402Version": 2,
"x402_invoice": {
"amount": "0.003",
"currency": "USDC",
"payment_id": "deef555d-50bd-4530-86d5-dda6b31cf03a",
"description": "One request to /api/v1/x402_endpoint_preflight",
"submit_headers": [
"x-402-payment-tx",
"x-402-payment-id"
],
"accepted_networks": [
{
"asset": "USDC",
"network": "base",
"chain_id": 8453,
"asset_contract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"destination_address": "0x8647F7D7a1368a467Ad1FF757fBc2e7167973558"
}
],
"expires_in_seconds": 900
},
"marketplace_metadata": {
"source": "live endpoint probe, Coinbase x402 Bazaar discovery, and 402index directory",
"billable": true,
"data_mode": "live_source",
"availability": "operational"
}
}Accepts
The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.
0.003USDC≈ $0.003 USD
on Base · exact scheme
Pay 0.003 USDC on Base to 0x8647…73558. The signed payment is good for 5 minutes.
- Paid to
- 0x8647…73558
- USD Coin contract
- 0x8335…02913
- Payment window
- 5 minutes
- As published
- 3000 smallest units
The catalog’s raw entry
[
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0x8647F7D7a1368a467Ad1FF757fBc2e7167973558",
"amount": "3000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 300
}
]Extensions
{
"bazaar": {
"info": {
"input": {
"body": {
"url": "https://example.com/api/paid",
"method": "GET"
},
"type": "http",
"method": "POST",
"bodyType": "json"
},
"output": {
"type": "json",
"example": {
"success": true,
"decision": "payment_challenge_is_structurally_ready",
"discovery": {
"coinbase_bazaar": {
"checked": true,
"exact_match_count": 1
}
},
"ready_for_payment": true,
"payment_requirements": []
}
}
},
"schema": {
"type": "object",
"$schema": "https://json-schema.org/draft/2020-12/schema",
"required": [
"input"
],
"properties": {
"input": {
"type": "object",
"required": [
"type",
"method",
"bodyType",
"body"
],
"properties": {
"body": {
"type": "object",
"required": [
"url"
],
"properties": {
"url": {
"type": "string",
"description": "Public HTTP or HTTPS endpoint to inspect without paying."
},
"method": {
"type": "string",
"description": "GET, HEAD, or POST. Defaults to GET."
},
"request_body": {
"type": "object",
"description": "Optional JSON body for a POST probe. Payment credentials are never forwarded."
}
},
"additionalProperties": true
},
"type": {
"type": "string",
"const": "http"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
}
},
"additionalProperties": false
},
"output": {
"type": "object",
"required": [
"type"
],
"properties": {
"type": {
"type": "string"
},
"example": {
"type": "object",
"required": [
"success",
"ready_for_payment",
"decision",
"payment_requirements",
"discovery"
],
"properties": {
"success": {
"type": "boolean"
},
"decision": {
"type": "string"
},
"discovery": {
"type": "object",
"required": [
"coinbase_bazaar"
],
"properties": {
"coinbase_bazaar": {
"type": "object",
"required": [
"checked",
"exact_match_count"
],
"properties": {
"checked": {
"type": "boolean"
},
"exact_match_count": {
"type": "integer"
}
},
"additionalProperties": true
}
},
"additionalProperties": true
},
"ready_for_payment": {
"type": "boolean"
},
"payment_requirements": {
"type": "array",
"items": {}
}
},
"additionalProperties": true
}
}
}
}
}
}
}Provenance
- Seen in the source catalog
- 2026-08-16 01:58Z
- Last indexed by Roundhouse
- 2026-09-15 01:50Z
- Last enriched (probe, favicon, geo)
- 2026-09-22 01:45Z
- 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
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 21 snapshots so far. 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 Endpoint Buyer 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%20Endpoint%20Buyer%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://ai-data-marketplace-1042299154756.us-central1.run.app/api/v1/x402_endpoint_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. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402, or use an organization key from https://roundhouseai.io/dashboard/team. If you do not have Roundhouse tools or skills installed, read https://roundhouseai.io/skill.md first — it is the whole procedure.