# Bitcoin Market Cap & Dominance Metrics

> Bitcoin Market Cap & Dominance Metrics is a paid API for AI agents from api.web3identity.com, paid per call via x402, $0.010000/call, status unknown (last checked 2026-09-14).

Returns Bitcoin's current market capitalization, dominance percentage, rank, circulating supply, and currency denomination

## Facts

- Endpoint: GET https://api.web3identity.com/api/bitcoin/marketcap
- Price: $0.010000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-web3identity-com-7eefff08
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0y1G-UCe_JUyQV3w5TLfD

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 api-web3identity-com-7eefff08
```

Example prompt: What's Bitcoin's current market cap and dominance percentage — how much of the total crypto market does BTC control right now?

## When to prefer this

Use this endpoint when you need Bitcoin-specific market capitalization and dominance metrics rather than general token prices. Ideal for dashboards, portfolio tools, or macro crypto market analysis where BTC dominance and rank are required data points. Prefer this over generic token price endpoints when dominance and circulating supply are needed.

## Known failure modes

- Upstream data source unavailable — stale or missing market data
- Rate limiting or payment failure (402) if x402 payment not provided
- Network timeout if external price feed is slow
- Invalid or malformed response if provider data feed is down

## How this service works

Bitcoin market capitalization and dominance metrics

## Output

Returns a JSON object with Bitcoin's rank (number), currency (string), dominance (decimal percentage), marketCap (number in USD), and circulatingSupply (number of BTC)

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {}
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "rank": {
       "type": "number"
      },
      "currency": {
       "type": "string"
      },
      "dominance": {
       "type": "number"
      },
      "marketCap": {
       "type": "number"
      },
      "circulatingSupply": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-web3identity-com-7eefff08/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.web3identity.com](https://www.zero.xyz/host/api.web3identity.com/llms.txt)