Roundhouse

CertainData

CertainData gives your AI agent a budget it can spend across the open agent ecosystem and a catalogue we verify ourselves — under your rules, with a receipt for every call.

DataLiveeip155:8453Exactvia cdp
https://api.certaindata.ai/ca054d66abad4d6ea80ba43013b61743-cd/fx-rates/:base
RatesExchange RateFXCurrency
Calls · 30d
1→ 0%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 27 snapshots so far.
$0.15
Verified settled volume
17 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0070
Listed price
As published in the catalog. Always read the live 402 before paying.
1
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-08-28 14:15Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x9A4fb84633C690e422c33491D1FCC319849E6BB0

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"
      },
      "payTo": "0x9A4fb84633C690e422c33491D1FCC319849E6BB0",
      "amount": "7000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://api.certaindata.ai/ca054d66abad4d6ea80ba43013b61743-cd/fx-rates/:base",
    "tags": [
      "Rates",
      "Exchange Rate",
      "FX",
      "Currency"
    ],
    "iconUrl": "https://www.certaindata.ai/brand/certaindata-icon-512.png",
    "mimeType": "application/json",
    "description": "Mid-market reference rates for one base currency against all published currencies, from the European Central Bank.",
    "serviceName": "CertainData"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "pathParams": {
            "base": "string"
          },
          "queryParams": {
            "date": "string"
          }
        },
        "output": {
          "type": "json",
          "example": {}
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method",
              "pathParams"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET",
                  "HEAD",
                  "DELETE"
                ],
                "type": "string"
              },
              "pathParams": {
                "type": "object",
                "required": [
                  "base"
                ],
                "properties": {
                  "base": {
                    "type": "string",
                    "description": "Base currency as a 3-letter ISO code, e.g. EUR."
                  }
                }
              },
              "queryParams": {
                "type": "object",
                "properties": {
                  "date": {
                    "type": "string",
                    "description": "Optional. A specific date (YYYY-MM-DD) for a historical rate, e.g. 2026-01-01. Omit for the latest."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      },
      "routeTemplate": "/ca054d66abad4d6ea80ba43013b61743-cd/fx-rates/:base"
    }
  },
  "x402Version": 2
}

Accepts

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

0.007USDC≈ $0.007 USD
on Base · exact scheme

Pay 0.007 USDC on Base to 0x9A4f…E6BB0. The signed payment is good for 5 minutes.

Paid to
0x9A4f…E6BB0
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
7000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x9A4fb84633C690e422c33491D1FCC319849E6BB0",
    "amount": "7000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "pathParams": {
          "base": "string"
        },
        "queryParams": {
          "date": "string"
        }
      },
      "output": {
        "type": "json",
        "example": {}
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "pathParams"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "GET",
                "HEAD",
                "DELETE"
              ],
              "type": "string"
            },
            "pathParams": {
              "type": "object",
              "required": [
                "base"
              ],
              "properties": {
                "base": {
                  "type": "string",
                  "description": "Base currency as a 3-letter ISO code, e.g. EUR."
                }
              }
            },
            "queryParams": {
              "type": "object",
              "properties": {
                "date": {
                  "type": "string",
                  "description": "Optional. A specific date (YYYY-MM-DD) for a historical rate, e.g. 2026-01-01. Omit for the latest."
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    },
    "routeTemplate": "/ca054d66abad4d6ea80ba43013b61743-cd/fx-rates/:base"
  }
}

Provenance

Seen in the source catalog
2026-08-28 14:15Z
Last indexed by Roundhouse
2026-09-24 07:20Z
Last enriched (probe, favicon, geo)
2026-09-22 10:15Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 404
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. 27 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 CertainData 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=CertainData'
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://api.certaindata.ai/ca054d66abad4d6ea80ba43013b61743-cd/fx-rates/:base, 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.