# Bitcoin Fee Estimates

> Bitcoin Fee Estimates is a paid API for AI agents from bess-x402.onrender.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-30).

Returns current Bitcoin network fee rates in sat/vB for multiple urgency tiers (next block, 30 min, 1 hour, economy), plus mempool size, block height, and typical payment cost.

## Facts

- Endpoint: GET https://bess-x402.onrender.com/v1/crypto/btc-fees?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-fee-estimates-57c456fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_swzvBu-RR4G9FOy8hIg4V

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-fee-estimates-57c456fa
```

Example prompt: Before I send this Bitcoin payment, can you check the current BTC network fees — specifically what sat/vB rate I'd need for next-block confirmation, and what the cheapest economy rate is right now?

## When to prefer this

Use this endpoint immediately before broadcasting a Bitcoin transaction when you need real-time, tiered fee recommendations across four urgency levels (next block through economy). Prefer it over generic crypto data APIs when you specifically need mempool depth and sat/vB estimates rather than price data. The bundled typical-payment cost figure is useful for user-facing fee previews without additional computation.

## Known failure modes

- Upstream Bitcoin node or mempool data source is unavailable — returns 5xx error
- Stale data if mempool feed is delayed
- Rate limiting or payment failure on x402 if USDC balance insufficient
- No input parameters accepted; any query params are ignored silently

## How this service works

Bitcoin network fee rates in sat/vB for next block, 30 minutes, 1 hour and economy, plus mempool size, block height and the cost of a typical payment. Use right before sending BTC.

## Output

A JSON object containing fee rates in sat/vB for four urgency tiers (next block, ~30 minutes, ~1 hour, economy), current mempool size, latest block height, and the estimated cost in fiat/BTC of a typical payment transaction.

## 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",
      "HEAD",
      "DELETE"
     ],
     "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-fee-estimates-57c456fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bess-x402.onrender.com](https://www.zero.xyz/host/bess-x402.onrender.com/llms.txt)