# Bitcoin Mempool Size & Unconfirmed Transaction Count

> Bitcoin Mempool Size & Unconfirmed Transaction Count 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 current Bitcoin mempool size (in bytes) and number of unconfirmed transactions, sourced from the mempool.space API

## Facts

- Endpoint: GET https://finance-api.kdlcfa.workers.dev/btc-mempool-size
- 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-mempool-size-unconfirmed-transaction-count-9d1bef1b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lpEY3K0ObeB5Qk3EnZhsp

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-mempool-size-unconfirmed-transaction-count-9d1bef1b
```

Example prompt: What's the current Bitcoin mempool size and how many unconfirmed transactions are sitting in the queue right now?

## When to prefer this

Use this endpoint when you need a quick, real-time snapshot of Bitcoin network congestion — specifically mempool size and unconfirmed transaction count — without needing block-level detail or fee histogram data. Ideal for fee-timing decisions, dashboard widgets, or network health monitoring. The $0.01/call pricing is suitable for periodic polling.

## Known failure modes

- mempool.space API upstream outage returns error or stale data
- network timeout from Cloudflare Worker to upstream
- payment not processed (402 if x402 payment header is missing or incorrect)
- rate limiting if called too frequently

## How this service works

Bitcoin mempool size and unconfirmed transaction count, via mempool.space API

## Output

Returns the current Bitcoin mempool size in bytes and the count of unconfirmed transactions pending in the mempool, sourced in real-time from the mempool.space API.

## 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-mempool-size-unconfirmed-transaction-count-9d1bef1b/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)