# Bitcoin Mempool Fee Rates

> Bitcoin Mempool Fee Rates 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 current Bitcoin mempool recommended fee rates in sat/vbyte across different priority tiers, sourced from mempool.space

## Facts

- Endpoint: GET https://api.chainmarket-api.workers.dev/api/finance/mempool-bitcoin?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-mempool-fee-rates-140502c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TPTAUko5nwjbgKfym28gG

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-fee-rates-140502c8
```

Example prompt: What are the current Bitcoin mempool fee rates? I want to know how much I should set for fastest confirmation versus a cheaper hour-long wait.

## When to prefer this

Use this endpoint when you need real-time Bitcoin fee rate data without signing up for an API key or managing credentials. It is pay-per-call via x402/USDC micro-payment, making it ideal for agents that need on-demand fee data infrequently. Prefer this over running your own mempool node or managing a separate API subscription when cost per call ($0.002 USDC) is acceptable.

## Known failure modes

- Upstream mempool.space API unavailable — may return 502 or stale data
- Network timeout from Cloudflare Worker — returns error with no charge
- Unexpected schema changes from mempool.space could cause parsing errors

## How this service works

Bitcoin network snapshot from mempool.space: recommended fee rates (sat/vB) for fastest, half-hour, hour and economy confirmation, plus the current chain tip height. Live network data; no prices.

## Output

Returns a JSON object with the current Bitcoin block tip height, the timestamp of the check, the source URL (mempool.space), and recommended fee rates in sat/vbyte for five priority tiers: fastest, halfHour, hour, economy, and minimum.

## 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"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "source": "https://mempool.space/api/v1/fees/recommended",
  "checkedAt": "2026-10-23T09:36:13.253Z",
  "tipHeight": 972749,
  "feeRatesSatPerVb": {
   "hour": 1,
   "economy": 1,
   "fastest": 2,
   "minimum": 1,
   "halfHour": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-mempool-fee-rates-140502c8/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)