Browser or mobile
Pay with a wallet
Use an installed EVM wallet, or open Coinbase Wallet through a desktop QR code or mobile handoff.
Run x402 endpoint preflight.
API Acre verifies the exact x402 price, Base network, recipient, and request before any wallet opens. One successful call costs $0.05 USDC.
No accountNo subscriptionNo private-key uploadOne-call authorization
API Acre never receives your private key; signing stays inside your wallet.
Verified mobile quick start
Connecting opens Coinbase Wallet. It does not sign or pay.
Loading a no-payment verification…
Verified live x402 quote
1 · Choose how to run one call
Both routes use this exact verified request and one-call price. Nothing is connected, signed, installed, or paid until you continue.
Agent or terminal
Use Coinbase Agentic Wallet
Copy a command locked to this endpoint, request, and exact USDC cap. Copying is inert; running it may install the official CLI and pay after its authentication and policy checks.
Wallet recovery
Choose another verified routeThe wallet did not connect, so nothing was signed or paid. Copy this same request and exact USDC cap for Coinbase Agentic Wallet; copying does not install or run it.
- Network
- Recipient
- USDC contract
No ETH gas needed. Connecting does not sign or pay. This EIP-3009 payment needs only the displayed USDC on Base because the facilitator submits settlement. Reject any later prompt that differs from the verified amount or recipient.
Review exact-cap Coinbase command
Running this command may automatically spend up to $0.05 USDC. npx --yes approves package installation. Use a separate low-value wallet and review the verified request first.
npx --yes awal@latest x402 pay https://apiacre.com/v1/developer/x402-preflight \
-X POST \
-d '{"url":"https://apiacre.com/v1/developer/openapi-audit","method":"POST","body":{"document":"{\"openapi\":\"3.1.0\",\"info\":{\"title\":\"Example\",\"version\":\"1\"},\"paths\":{}}","format":"json"},"market_query":"audit","market_limit":1}' \
--max-amount 50000 \
--jsonAlternative third-party AgentCash command
The first command checks without paying; running fetch may pay up to the same exact cap.
npx --yes agentcash@latest check https://apiacre.com/v1/developer/x402-preflight
npx --yes agentcash@latest fetch https://apiacre.com/v1/developer/x402-preflight \
--method POST \
--header 'content-type: application/json' \
--body '{"url":"https://apiacre.com/v1/developer/openapi-audit","method":"POST","body":{"document":"{\"openapi\":\"3.1.0\",\"info\":{\"title\":\"Example\",\"version\":\"1\"},\"paths\":{}}","format":"json"},"market_query":"audit","market_limit":1}' \
--payment-protocol x402 \
--payment-network base \
--max-amount 0.05See the result before connecting · Curated static example
x402 endpoint preflight returns structured JSON. This example is static; the paid call returns a fresh result and settlement receipt.
{
"request_id": "018f1f54-7f38-7ba2-8dc3-5f90272d9f1a",
"service": "developer.x402-preflight",
"version": "1",
"data": {
"url": "https://apiacre.com/v1/developer/openapi-audit",
"finalUrl": "https://apiacre.com/v1/developer/openapi-audit",
"method": "POST",
"statusCode": 402,
"elapsedMs": 128,
"compliant": true,
"grade": "A",
"score": 100,
"gradeVersion": "apiacre-x402-preflight/1",
"checks": [
{
"id": "http_402",
"passed": true,
"severity": "high",
"message": "Return HTTP 402 before payment."
},
{
"id": "header_decodes",
"passed": true,
"severity": "high",
"message": "PAYMENT-REQUIRED decodes to a JSON object."
},
{
"id": "x402_v2",
"passed": true,
"severity": "high",
"message": "Set x402Version to the integer 2."
},
{
"id": "caip2_network",
"passed": true,
"severity": "high",
"message": "Use a valid CAIP-2 network identifier."
},
{
"id": "resource_binding",
"passed": true,
"severity": "medium",
"message": "Bind resource.url to the endpoint that returned the payment requirement."
}
],
"payment": {
"version": 2,
"acceptsCount": 1,
"scheme": "exact",
"network": "eip155:8453",
"amount": "50000",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"payTo": "0xa0BFa4f07281c9b248DC3AED2217836BcA24869B"
},
"directoryEvidence": {
"version": "apiacre-x402-directory-evidence/1",
"source": {
"name": "x402 List",
"url": "https://x402-list.com",
"apiUrl": "https://x402-list.com/api/v1/services",
"documentationUrl": "https://x402-list.com/api",
"license": "CC-BY-4.0",
"licenseUrl": "https://creativecommons.org/licenses/by/4.0/",
"attributionRequired": true,
"attribution": "Data: x402-list.com (CC BY 4.0)",
"access": "No-auth read with a 2,000-request daily free quota; API Acre never pays the upstream."
},
"target": {
"status": "matched",
"hostname": "apiacre.com",
"matchMethod": "exact_host",
"matchCount": 1,
"matches": [
{
"slug": "api-acre",
"name": "API Acre",
"description": "Pay-per-call x402 APIs for agents with machine-readable schemas and samples.",
"baseUrl": "https://apiacre.com",
"websiteUrl": "https://apiacre.com",
"category": "Data",
"status": "online",
"verified": false,
"paymentReady": true,
"endpointCount": 35,
"networks": [
"eip155:8453"
],
"priceUsd": {
"minimum": 0.001,
"maximum": 0.25
},
"compliance": {
"grade": "A",
"passed": 14,
"total": 14
},
"reliability": {
"uptime30dPct": 99.6,
"responseP95Ms": 223,
"priceStability": 0.0
},
"traction": {
"status": "measured",
"volumeUsdc30d": 2.124,
"settlements30d": 74,
"uniqueBuyers30d": 5,
"topBuyerShare30d": 0.943503,
"volumeOutsideTopBuyerUsdc30d": 0.12,
"sharedPayout": false,
"sharedWith": 0,
"proQuotaShare": 1.0,
"lastSettlementAt": "2026-08-14T14:29:25Z",
"caveat": "Conservative measured floor; operator validation can be present and is not identified by the directory."
},
"lastCheckedAt": "2026-08-15T04:23:09.951Z",
"assessmentUpdatedAt": "2026-08-15T01:43:05.729Z"
}
],
"retrievedAt": "2026-08-15T04:30:00+00:00",
"cached": false,
"reason": null
},
"market": {
"status": "ok",
"query": "audit",
"totalMatches": 31,
"returned": 1,
"sourcePageTruncated": false,
"results": [
{
"slug": "webbersites-x402-data-api",
"name": "WebberSites x402 Data API",
"description": "Pay-per-call data and utility API for AI agents with web, document, developer, and structured-data tools.",
"baseUrl": "https://api.webbersites.com",
"websiteUrl": "https://x402.webbersites.com",
"category": "Data",
"status": "online",
"verified": false,
"paymentReady": true,
"endpointCount": 37,
"networks": [
"eip155:8453"
],
"priceUsd": {
"minimum": 0.001,
"maximum": 0.05
},
"compliance": {
"grade": "A",
"passed": 14,
"total": 14
},
"reliability": {
"uptime30dPct": 100.0,
"responseP95Ms": 205,
"priceStability": 0.0
},
"traction": {
"status": "measured",
"volumeUsdc30d": 4.274,
"settlements30d": 443,
"uniqueBuyers30d": 70,
"topBuyerShare30d": 0.332007,
"volumeOutsideTopBuyerUsdc30d": 2.855,
"sharedPayout": false,
"sharedWith": 0,
"proQuotaShare": 1.0,
"lastSettlementAt": "2026-08-14T23:18:13Z",
"caveat": "Conservative measured floor; service-level activity is not endpoint attribution or a revenue forecast."
},
"lastCheckedAt": "2026-08-15T04:41:09.686Z",
"assessmentUpdatedAt": "2026-08-15T01:33:01.858Z"
}
],
"retrievedAt": "2026-08-15T04:30:00+00:00",
"cached": false,
"reason": null,
"rankingMethod": "Unique buyers, then volume outside the top buyer, settlements, and volume; missing measurements rank last."
},
"limitations": [
"Directory and traction observations are time-specific measured floors, not endorsements or forecasts.",
"Distinct buyers and settlements are service-level measurements and cannot be summed into ecosystem-unique totals.",
"Shared-payout fields and the source caveat must be inspected before comparing services.",
"The target hostname and optional market query are sent to x402-list.com without credentials or payment headers."
]
},
"remediation": [],
"checkedAt": "2026-08-09T00:00:00+00:00",
"limitations": "One unpaid target request only; no payment is signed and the target response is not retained. Licensed directory enrichment is time-specific and may be unavailable."
},
"meta": {
"duration_ms": 42,
"cached": false,
"sources": [],
"warnings": [],
"next_actions": []
}
}Review exact request JSON
2 · Authorize one call
- Connected wallet
- Available on Base
- Checking USDC…
- Required
- $0.05 USDC
Checking the connected wallet's Base USDC balance without signing or paying.
Signing authorizes only the verified amount and recipient for this request. Reject the wallet prompt if anything differs. The displayed balance is read locally through your wallet provider and is never sent to API Acre.
Result
Settlement receipt
Delivered in production
Independently purchasedAt least one independently attributed settlement was observed for this service through . Operator validation is excluded.
Review the aggregate claim boundaryIndependent monitoring
Live x402 handshake reportThe x402 Register independently checks API Acre's unpaid challenge, price, protocol version, and availability. It does not purchase or validate paid results.
Open the current report ↗Change the request (optional)
The default request is verified automatically. Editing it invalidates the quote and requires this no-payment verification again.
Prefer your own client? Use the official x402 SDK examples. Browser checkout requires an EVM wallet with USDC on Base; command-line buyers require their own separately configured wallet and spending policy.