# 2s BTC Fee Estimator

> 2s BTC Fee Estimator is a paid API for AI agents from 2s.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns real-time Bitcoin mempool statistics and recommended fee rates (sat/vByte) across priority tiers

## Facts

- Endpoint: GET https://2s.io/api/crypto/btc-fees
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/2s-btc-fee-estimator-5af9a441
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_V2U7ToUtVVgwR0Qe9QI-2

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 2s-btc-fee-estimator-5af9a441
```

Example prompt: What's the current Bitcoin fee rate — specifically what sat/vByte should I use to get confirmed within the next 30 minutes, and how congested is the mempool right now?

## When to prefer this

Use this endpoint when an agent needs real-time Bitcoin fee estimates and mempool health without managing API keys or accounts. Prefer over direct mempool.space calls when operating in an x402 pay-per-call environment. Ideal for wallets, payment bots, or any agent sending BTC transactions and needing to pick an appropriate fee tier.

## Known failure modes

- Upstream mempool.space API unavailable — stale or empty data returned
- Network timeout — agent should retry
- Payment not received — 402 response returned, no data
- Mempool data momentarily inconsistent during high-congestion spikes

## How this service works

The (most) everything API: 575+ pay-per-call endpoints for AI agents — ground-truth data, a full AI gateway, and agent infrastructure (storage, queues, watchers). USDC via x402, no signup, no API keys, and upto billing: pay actual usage, not the quote.

## Output

Returns a JSON object containing current Bitcoin mempool stats (transaction count, virtual size in bytes, total fees in satoshis) and recommended fee rates in sat/vByte for five priority tiers: fastest, half-hour, hour, economy, and minimum. Also includes source attribution from mempool.space.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/2s-btc-fee-estimator-5af9a441/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 2s.io](https://www.zero.xyz/host/2s.io/llms.txt)