# CoinCap Exchange Rates via SiteCheck Crypto & Finance

> CoinCap Exchange Rates via SiteCheck Crypto & Finance is a paid API for AI agents from api.chainmarket-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-24).

Fetches real-time USD-based exchange rates for fiat and crypto currencies sourced from Coinbase, filterable by currency symbol, name, or type.

## Facts

- Endpoint: GET https://api.chainmarket-api.workers.dev/api/finance/coincap-rates?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/coincap-exchange-rates-via-sitecheck-crypto-finance-01fa6001
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5Ats2xr8fd7jtp2Lx7vUj

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability coincap-exchange-rates-via-sitecheck-crypto-finance-01fa6001
```

Example prompt: What's the current exchange rate for Euro and Bitcoin in USD? Pull the live rates from CoinCap and show me the perUsd and rateUsd values for both.

## When to prefer this

Choose this endpoint when you need real-time USD-denominated exchange rates for both fiat currencies and cryptocurrencies sourced from Coinbase, require no signup or API key, and are operating in a pay-per-call micropayment context via x402. Prefer this over subscription APIs when call volume is low or unpredictable, or when you need broad multi-chain payment flexibility.

## Known failure modes

- Unknown currency symbol or name returns empty results array
- Invalid type parameter value may return no results or error
- Payment failure (402) results in no charge and no data returned
- Network or upstream Coinbase API outage may return 5xx error
- Omitting required input wrapper may cause validation error

## How this service works

Exchange rates against the US dollar for about 170 fiat currencies and 400+ cryptocurrencies (Coinbase public rates): symbol, name, fiat or crypto, USD value of one unit and units per USD. All rates, a fiat/crypto filter, or one currency by symbol (EUR, BTC, TRY) or name (euro, bitcoin, turkish-lira).

## Output

Returns a JSON object with base currency (USD), count of results, source URL, a timestamp (checkedAt), and an array of matched currencies each containing id, name, symbol, type (fiat or crypto), perUsd (units of currency per 1 USD), and rateUsd (USD value of 1 unit of that currency).

## Request schema (JSON Schema)

```json
{
 "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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "id": {
       "type": "string",
       "description": "Currency symbol (EUR, BTC) or name (euro, bitcoin, turkish-lira); omit for all"
      },
      "type": {
       "type": "string",
       "description": "fiat or crypto (filter for the full list)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "base": "USD",
  "count": 1,
  "source": "https://api.coinbase.com/v2/exchange-rates?currency=USD",
  "results": [
   {
    "id": "euro",
    "name": "Euro",
    "type": "fiat",
    "perUsd": 0.8932393333333333,
    "symbol": "EUR",
    "rateUsd": 1.119520785
   }
  ],
  "checkedAt": "2026-10-23T09:36:14.468Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/coincap-exchange-rates-via-sitecheck-crypto-finance-01fa6001/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.chainmarket-api.workers.dev](https://www.zero.xyz/host/api.chainmarket-api.workers.dev/llms.txt)