# Bitcoin Total Supply Lookup

> Bitcoin Total Supply Lookup is a paid API for AI agents from finance-api.kdlcfa.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns the total number of Bitcoin currently in circulation, sourced from the Blockchain.info stats API

## Facts

- Endpoint: GET https://finance-api.kdlcfa.workers.dev/btc-total-supply
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-total-supply-lookup-74799fe2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uRp7AojJiXWon6R6AYnAk

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-total-supply-lookup-74799fe2
```

Example prompt: What is the total amount of Bitcoin currently in circulation according to Blockchain.info?

## When to prefer this

Choose this endpoint when you need a simple, single scalar representing total circulating Bitcoin supply, sourced directly from Blockchain.info. Prefer this over general crypto market APIs when you specifically need the on-chain supply metric rather than price or market cap data. Best for dashboards, research, or monitoring use cases that require a quick, cheap data point without complex query construction.

## Known failure modes

- Upstream Blockchain.info stats API unavailable — proxy returns 5xx error
- Unit ambiguity: value may be in satoshis rather than whole BTC, requiring downstream division by 100,000,000
- Delayed or stale data if Blockchain.info cache hasn't updated recently
- Payment failure due to insufficient x402 USDC balance, resulting in 402 response

## How this service works

Total Bitcoin in circulation (raw value as returned by upstream, unit to be verified empirically), via Blockchain.info stats API

## Output

A raw numeric value representing the total number of Bitcoin units currently in circulation, as returned by the Blockchain.info stats API. The exact unit (BTC vs satoshis) should be verified empirically, but typically represents the total mined supply.

## 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": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-total-supply-lookup-74799fe2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from finance-api.kdlcfa.workers.dev](https://www.zero.xyz/host/finance-api.kdlcfa.workers.dev/llms.txt)