# Bitcoin Whale Alert Transfers

> Bitcoin Whale Alert Transfers 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).

Returns large Bitcoin transactions from the latest block, filtered by minimum BTC output, sourced from mempool.space

## Facts

- Endpoint: GET https://api.chainmarket-api.workers.dev/api/crypto/whale-alert-transfers?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/bitcoin-whale-alert-transfers-30d35d71
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WBI91u5ZX-QG9y3v8NOKQ

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-whale-alert-transfers-30d35d71
```

Example prompt: Show me the top 5 Bitcoin transactions from the latest block that moved at least 2 BTC — I want to track whale activity on-chain.

## When to prefer this

Use this endpoint when you need real-time, pay-per-call access to large Bitcoin on-chain transactions without API keys or subscriptions. Ideal for agents monitoring whale activity, building alert systems, or doing lightweight on-chain research. Prefer this over exchange APIs when you need raw blockchain-level transfer data rather than trading volume or order book data.

## Known failure modes

- Payment failure if insufficient USDC balance — call not charged on failure
- Invalid limit value outside 1–25 range returns error
- Invalid minBtc value outside 0.01–10000 range returns error
- Upstream mempool.space unavailability may cause timeout or empty response
- No transactions matching the minBtc threshold returns empty transfers array

## How this service works

Bitcoin large transactions in the latest block from mempool.space: total output in BTC, fee, txid and block height, filtered by minBtc. Bitcoin only (no ETH or SOL). Covers the first 25 transactions of the tip block; output total includes change, so it is transaction size, not one wallet's transfer.

## Output

Returns a JSON object with a count of matching transactions, the source block hash, the timestamp of the check, and an array of transaction records each containing txid, fee in satoshis, block time, input count, output count, block height, and total output in BTC.

## 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": {
      "limit": {
       "type": "string",
       "description": "How many transactions to return, 1 to 25 (default 10)"
      },
      "minBtc": {
       "type": "string",
       "description": "Minimum total output in BTC, 0.01 to 10000 (default 1)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 3,
  "source": "https://mempool.space/api/block/000000000000000000015d1494dfcf12bfc97f6ff50eec3c622091e707183436/txs",
  "blockHash": "000000000000000000015d1494dfcf12bfc97f6ff50eec3c622091e707183436",
  "checkedAt": "2026-10-23T09:35:53.973Z",
  "transfers": [
   {
    "txid": "ab4f2d8e06db1c799dabdc5716288e8e128cec6af79f3122fe415aa9732a79c5",
    "feeSats": 0,
    "blockTime": "2026-10-23T09:27:57.000Z",
    "inputCount": 1,
    "blockHeight": 972749,
    "outputCount": 6,
    "totalOutputBtc": 3.13056286
   },
   {
    "txid": "ca2949e6d137d0dd135381185e22d8396a45fadbeb1e3836899fe7a832054d3c",
    "feeSats": 6195,
    "blockTime": "2026-10-23T09:27:57.000Z",
    "inputCount": 5,
    "blockHeight": 972749,
    "outputCount": 2,
    "totalOutputBtc": 1.09203195
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-whale-alert-transfers-30d35d71/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)