Roundhouse

tariffmonkee.com

Small, single-purpose web data APIs that AI agents pay for per call in USDC over the x402 protocol (HTTP 402). No accounts, no API keys, no subscriptions.

TradingLiveeip155:8453Uptovia cdp
https://tariffmonkee.com/paid/a2a
Calls · 30d
14→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 25 snapshots so far.
$3.72
Verified settled volume
71 settlements proven x402 by their on-chain EIP-3009 marker.
$0.750
Listed price
As published in the catalog. Always read the live 402 before paying.
14
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-09-03 06:51Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x0FAD15c9f4C38f439fd56C4d4e4Bc8fC71c42767

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": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2",
        "facilitatorAddress": "0x93F6601151cCB08F333AB4B1CCcfb1e188c0bE44",
        "assetTransferMethod": "permit2"
      },
      "payTo": "0x0FAD15c9f4C38f439fd56C4d4e4Bc8fC71c42767",
      "amount": "750000",
      "scheme": "upto",
      "network": "base",
      "mimeType": "application/json",
      "resource": "https://tariffmonkee.com/paid/a2a",
      "description": "A2A (Agent2Agent) protocol JSON-RPC endpoint, SendMessage only. Authorizes up to $0.75 (the highest-priced skill); settlement charges the invoked skill's real per-skill price. Base (EVM) only -- for Solana use the REST or MCP endpoints. See /.well-known/agent-card.json for the skill catalog and per-skill pricing.",
      "maxAmountRequired": "750000",
      "maxTimeoutSeconds": 300
    }
  ],
  "x402Version": 1
}

Accepts

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

0.75USDC≈ $0.75 USD
on Base · upto scheme

Pay 0.75 USDC on Base to 0x0FAD…42767. The signed payment is good for 5 minutes.

Paid to
0x0FAD…42767
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
750000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2",
      "facilitatorAddress": "0x8F5cB67B49555E614892b7233CFdDEBFB746E531",
      "assetTransferMethod": "permit2"
    },
    "payTo": "0x0FAD15c9f4C38f439fd56C4d4e4Bc8fC71c42767",
    "amount": "750000",
    "scheme": "upto",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {},
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      }
    },
    "schema": {
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "properties": {
            "body": {
              "type": "object"
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "bodyType": {
              "enum": [
                "json"
              ],
              "type": "string"
            }
          },
          "additionalProperties": false
        }
      }
    },
    "routeTemplate": "/paid/a2a"
  },
  "builder-code": {
    "info": {
      "s": [
        "cdp_sdk_server"
      ]
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "a": {
          "type": "string",
          "pattern": "^[a-z0-9_]{1,32}$",
          "description": "App builder code"
        },
        "s": {
          "type": "array",
          "items": {
            "type": "string",
            "pattern": "^[a-z0-9_]{1,32}$"
          },
          "maxItems": 11,
          "description": "Service builder codes"
        },
        "w": {
          "type": "string",
          "pattern": "^[a-z0-9_]{1,32}$",
          "description": "Wallet builder code"
        }
      },
      "additionalProperties": false
    }
  },
  "eip2612GasSponsoring": {},
  "erc20ApprovalGasSponsoring": {}
}

Provenance

Seen in the source catalog
2026-09-03 06:51Z
Last indexed by Roundhouse
2026-09-24 09:50Z
Last enriched (probe, favicon, geo)
2026-09-22 01:15Z
x402 version
2
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. 25 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 tariffmonkee.com 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=tariffmonkee.com'
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://tariffmonkee.com/paid/a2a, 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.