# ScriptMasterLabs BTC Mempool Fees API

> ScriptMasterLabs BTC Mempool Fees API is a paid API for AI agents from acp-x402-discovery.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns current Bitcoin mempool fee estimates (e.g. slow, standard, fast sat/vB rates) via a pay-per-call x402/USDC endpoint

## Facts

- Endpoint: GET https://acp-x402-discovery.onrender.com/x402/btc-mempool-fees
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/scriptmasterlabs-btc-mempool-fees-api-1f2f39fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uc8UMdA4vid5cqyPwlOGX

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 scriptmasterlabs-btc-mempool-fees-api-1f2f39fa
```

Example prompt: What are the current Bitcoin mempool fee rates — give me the slow, standard, and fast sat/vB estimates so I can decide how to price my transaction right now.

## When to prefer this

Choose this endpoint when you need real-time Bitcoin mempool fee estimates in a pay-per-call micro-payment model settled in USDC on Base via the x402 protocol. Prefer it in automated agent workflows that need on-demand BTC fee data without a subscription, or when integrating with x402-native payment infrastructure. Alternative free endpoints (mempool.space API, Blockstream) may be preferred for high-volume or unauthenticated use cases.

## Known failure modes

- Payment failure: x402 USDC payment on Base not processed — endpoint returns 402 Payment Required
- Upstream mempool data source unavailable — may return 503 or empty/stale data
- Malformed or empty response body if the underlying mempool feed is down
- Rate limiting or provider outage on Render-hosted service causing timeouts

## How this service works

Pay-per-call crypto, RWA, federal, SEC, and compliance APIs. Settled in USDC on Base via x402. Hyphen routes only (e.g. /x402/rwa-aggregates, /x402/gas-tracker).

## Output

Returns current Bitcoin mempool fee estimates broken down by priority tier (slow, standard, fast), expressed in satoshis per virtual byte (sat/vB), reflecting real-time mempool congestion conditions. Response is a JSON object with fee rate data per confirmation speed tier.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "example": {}
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/scriptmasterlabs-btc-mempool-fees-api-1f2f39fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from acp-x402-discovery.onrender.com](https://www.zero.xyz/host/acp-x402-discovery.onrender.com/llms.txt)