Roundhouse

verify.sarnai.dev

Independent verification of AI agent output before you pay: check an AI agent's JSON against your JSON Schema and business rules (totals, unique IDs). Signed attestation and receipt over MCP and REST. By SarnAI. - sarnai-dev/agent-output-verifier

OtherLiveeip155:8453Exactvia facilitator:thirdweb
https://verify.sarnai.dev/verify/schema
Calls · 30d
4
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 16 snapshots so far.
$0.55
Verified settled volume
32 settlements proven x402 by their on-chain EIP-3009 marker.
$0.020
Listed price
As published in the catalog. Always read the live 402 before paying.
—
Calls · 30d
Upstream's own call count for this endpoint, not ours.
—
Unique payers · 30d
Never called
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x42a3c399f83BCcC3b9eEf81e65954a715D54855E

The 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": "No payment was attached to the request.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x42a3c399f83BCcC3b9eEf81e65954a715D54855E",
      "amount": "20000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "GVJJ7rdGiXr5xaYbRwRbjfaJL7fmwRygFi1H6aGqDveb"
      },
      "payTo": "38Fmaf3MWTR6AWPWrtrdXoqn6iqfVcUBHMFRhiUAEjFb",
      "amount": "20000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    }
  ],
  "guidance": {
    "docs": {
      "openapi": "https://verify.sarnai.dev/openapi.json",
      "llms_txt": "https://verify.sarnai.dev/llms.txt"
    },
    "price": "$0.02 USDC per call (POST /verify/schema and /verify/deliverable); GET /score/{agent_id} is $0.01 USDC",
    "how_to_pay": "Send the request with no payment: the 402 answer lists the price and networks (USDC on Base or Solana) in the PAYMENT-REQUIRED header (x402 v2). Sign it with an x402 client and resend the same request with the PAYMENT-SIGNATURE header. The MCP tool at https://verify.sarnai.dev/mcp takes the same arguments.",
    "what_to_do": "Pay with x402 v2 as described in how_to_pay, or send a valid request while the free allowance lasts. Nothing was charged by this response.",
    "free_allowance": {
      "message": "Free during launch: 1000 verification checks a day per caller through MCP and REST (POST /verify/schema and POST /verify/deliverable), then $0.02 USDC per call via x402.",
      "available": true,
      "resets_at": "2026-10-20T00:00:00+00:00",
      "applies_to": "valid requests to POST /verify/schema and POST /verify/deliverable and the MCP tool verify_schema; one count per client address",
      "remaining_calls_today": 993,
      "calls_per_client_per_day": 1000
    },
    "example_request": {
      "url": "https://verify.sarnai.dev/verify/schema",
      "body": {
        "task_id": "example-task-1",
        "expected_schema": {
          "type": "object",
          "required": [
            "total"
          ],
          "properties": {
            "total": {
              "type": "number"
            }
          }
        },
        "submitted_output": {
          "total": 42
        }
      },
      "method": "POST",
      "headers": {
        "Content-Type": "application/json"
      }
    }
  },
  "resource": {
    "url": "https://verify.sarnai.dev/verify/schema",
    "tags": [
      "json-schema",
      "output-validation",
      "attestation",
      "invoice",
      "x402"
    ],
    "mimeType": "application/json",
    "description": "Free during launch. Independent verification of AI agent output before you pay: an invoice or deliverable against your JSON Schema and rules. Pass/fail, % passed, fix hints, signed attestation and receipt. $0.02 USDC after, no signup, x402 v2.",
    "serviceName": "Agent Output Verifier"
  },
  "free_trial": {
    "url": "https://verify.sarnai.dev/mcp",
    "via": "mcp+rest",
    "tool": "verify_schema",
    "client": "identified by request IP address; the same address's REST and MCP verification calls share one allowance",
    "launch": true,
    "message": "Free during launch. 993 of 1000 free checks remain today for this client, shared by this REST endpoint and the MCP tool 'verify_schema' at https://verify.sarnai.dev/mcp. This request needs payment because the request body is not a valid verification request.",
    "available": true,
    "resets_at": "2026-10-20T00:00:00+00:00",
    "rest_free": true,
    "transport": "streamable-http",
    "declined_because": "invalid_request",
    "remaining_calls_today": 993,
    "calls_per_client_per_day": 1000
  },
  "probe_note": {
    "path": "/verify/schema",
    "method": "POST",
    "message": "The real call is POST /verify/schema with the output to check as a JSON body; this GET/HEAD answer is the payment challenge for it. A valid POST is served free while the launch allowance lasts, then paid.",
    "example_body": {
      "task_id": "example-task-1",
      "expected_schema": {
        "type": "object",
        "required": [
          "total"
        ],
        "properties": {
          "total": {
            "type": "number"
          }
        }
      },
      "submitted_output": {
        "total": 42
      }
    }
  },
  "x402Version": 2,
  "payment_error": {
    "charged": false,
    "message": "This call requires payment; none was attached.",
    "retryable": true,
    "error_code": "no_payment",
    "retry_after": null,
    "next_actions": [
      {
        "action": "submit_x402_v2_payment"
      }
    ],
    "payment_terms": {
      "accepts": [
        {
          "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
          "extra": {
            "name": "USD Coin",
            "version": "2"
          },
          "payTo": "0x42a3c399f83BCcC3b9eEf81e65954a715D54855E",
          "amount": "20000",
          "scheme": "exact",
          "network": "eip155:8453",
          "maxTimeoutSeconds": 300
        },
        {
          "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
          "extra": {
            "feePayer": "GVJJ7rdGiXr5xaYbRwRbjfaJL7fmwRygFi1H6aGqDveb"
          },
          "payTo": "38Fmaf3MWTR6AWPWrtrdXoqn6iqfVcUBHMFRhiUAEjFb",
          "amount": "20000",
          "scheme": "exact",
          "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
          "maxTimeoutSeconds": 300
        }
      ],
      "resource": {
        "url": "https://verify.sarnai.dev/verify/schema",
        "tags": [
          "json-schema",
          "output-validation",
          "attestation",
          "invoice",
          "x402"
        ],
        "mimeType": "application/json",
        "description": "Free during launch. Independent verification of AI agent output before you pay: an invoice or deliverable against your JSON Schema and rules. Pass/fail, % passed, fix hints, signed attestation and receipt. $0.02 USDC after, no signup, x402 v2.",
        "serviceName": "Agent Output Verifier"
      }
    }
  }
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

0.02USDC≈ $0.02 USD
on Base · exact scheme

Pay 0.02 USDC on Base to 0x42a3…4855E. The signed payment is good for 5 minutes.

Paid to
0x42a3…4855E
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
20000 smallest units
Returns
application/json
20000units
on solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · exact scheme

That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.

Paid to
38Fmaf…AEjFb
Token contract
EPjFWd…TDt1v
Payment window
5 minutes
Returns
application/json
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x42a3c399f83BCcC3b9eEf81e65954a715D54855E",
    "scheme": "exact",
    "network": "eip155:8453",
    "mimeType": "application/json",
    "resource": "https://verify.sarnai.dev/verify/schema",
    "description": "",
    "maxAmountRequired": "20000",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "extra": {
      "feePayer": "GVJJ7rdGiXr5xaYbRwRbjfaJL7fmwRygFi1H6aGqDveb"
    },
    "payTo": "38Fmaf3MWTR6AWPWrtrdXoqn6iqfVcUBHMFRhiUAEjFb",
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "mimeType": "application/json",
    "resource": "https://verify.sarnai.dev/verify/schema",
    "description": "",
    "maxAmountRequired": "20000",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog
2026-10-15 01:14Z
Last indexed by Roundhouse
2026-10-25 19:46Z
Last enriched (probe, favicon, geo)
2026-10-19 11:45Z
x402 version
1
Max timeout
300s
Liveness probe
HTTP 402
Report

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. 16 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service verify.sarnai.dev 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=verify.sarnai.dev'
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://verify.sarnai.dev/verify/schema, 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.