# Bitcoin Network BTC Supply

> Bitcoin Network BTC Supply is a paid API for AI agents from bitcoin-network.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Returns Bitcoin's issued supply, block subsidy, percent of 21M cap mined, and next halving details, computed exactly from protocol rules.

## Facts

- Endpoint: GET https://bitcoin-network.x402tookit.com/btc-supply?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-network-btc-supply-c700ed5e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kPmZ7ISUqz9AgJlmYLlQT

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 bitcoin-network-btc-supply-c700ed5e
```

Example prompt: What percentage of Bitcoin's 21 million cap has been mined so far, and how many days until the next halving? Show me the figures in BTC.

## When to prefer this

Choose this endpoint when you need precise, protocol-derived Bitcoin supply and halving metrics — including exact subsidy schedules, percent of cap mined, and halving countdown — computed deterministically from Bitcoin's consensus rules rather than scraped from a third-party explorer. Ideal for financial reports, dashboards, or any agent task requiring authoritative on-chain monetary policy figures.

## Known failure modes

- Invalid or future block height returns an error or null values
- If the live tip cannot be fetched, degraded flag may be set and cached/estimated values used
- Unsupported unit value (not 'btc' or 'sats') may return an error or default to BTC
- Network timeouts may result in partial or null response fields

## How this service works

Bitcoin issued supply, block subsidy, percent of 21 million mined and the next halving, computed exactly from protocol rules.

## Output

Returns a JSON object with the current (or specified) block height, total issued supply in BTC and satoshis, the 21M cap in BTC, percent of cap mined, current block subsidy, next block subsidy, halving epoch number, next halving block height, blocks until halving, estimated days until halving, and metadata fields like source, disclaimer, and degraded status.

## 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",
     "required": [],
     "properties": {
      "unit": {
       "type": "string",
       "description": "Headline unit: btc (default) or sats"
      },
      "height": {
       "type": "integer",
       "description": "Block height to compute at (default: current tip)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "capBtc": {
       "type": [
        "null",
        "number"
       ]
      },
      "height": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "issuedBtc": {
       "type": [
        "null",
        "number"
       ]
      },
      "sourceUrl": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "issuedSats": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "subsidyBtc": {
       "type": [
        "null",
        "number"
       ]
      },
      "halvingEpoch": {
       "type": [
        "null",
        "number"
       ]
      },
      "percentOfCap": {
       "type": [
        "null",
        "number"
       ]
      },
      "nextSubsidyBtc": {
       "typ
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-network-btc-supply-c700ed5e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bitcoin-network.x402tookit.com](https://www.zero.xyz/host/bitcoin-network.x402tookit.com/llms.txt)