# SYNTHORA Bitcoin Recommended Fee Oracle

> SYNTHORA Bitcoin Recommended Fee Oracle is a paid API for AI agents from bitcoin-recommended-fees.hergertsynthora.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns real-time recommended Bitcoin transaction fee rates (fastest, half-hour, hour, economy, and minimum in sat/vB) sourced from mempool.space

## Facts

- Endpoint: POST https://bitcoin-recommended-fees.hergertsynthora.com/service
- 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/synthora-bitcoin-recommended-fee-oracle-109203d6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_U3JGkZR3qtZkK6hvSLnBh

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 synthora-bitcoin-recommended-fee-oracle-109203d6 -d '<json body>'
```

Example prompt: What are the current Bitcoin fee rates — fastest, half-hour, hour, economy, and minimum in sat/vB — so I can size my transaction fee to confirm within 30 minutes without overpaying?

## When to prefer this

Choose this endpoint when an autonomous Bitcoin payment agent or settlement bot needs real-time, tiered fee recommendations (not just a single estimate) to hit a specific confirmation window at minimum cost. It is especially suited for agents operating in the x402 micropayment ecosystem and needing structured sat/vB data across five priority tiers sourced from mempool.space, with provenance metadata included.

## Known failure modes

- Upstream mempool.space API unavailability causing stale or missing data
- Network timeout resulting in no response
- Invalid or malformed request payload returning an error
- Rate limiting or payment failure (x402) if USDC balance is insufficient

## How this service works

Returns real-time recommended Bitcoin transaction fee rates (fastest, half-hour, hour, economy, minimum in sat/vB) from mempool.space. Serves autonomous BTC payment agents and agent-to-agent settlement bots that size fees to hit a target confirmation window without overpaying. First 3 calls FREE per wallet — send header X-WALLET: 0x<addr>. No charge on upstream failure.

## Output

A JSON object with ok:true and a result object containing five fee tiers in sat/vB: fastest_fee (next block), half_hour_fee (~3 blocks), hour_fee (~6 blocks), economy_fee (low priority), and minimum_fee (floor accepted by mempool). Provenance metadata is included, citing mempool.space as the source.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "keys": {
   "type": "string",
   "description": "keys"
  },
  "caller": {
   "type": "string",
   "description": "caller"
  },
  "payload": {
   "type": "string",
   "description": "payload"
  },
  "provides": {
   "type": "string",
   "description": "provides"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "bitcoin-recommended-fees",
  "result": {
   "hour_fee": 1,
   "economy_fee": 1,
   "fastest_fee": 1,
   "minimum_fee": 1,
   "half_hour_fee": 1
  },
  "provenance": {
   "url": "https://mempool.space/api/v1/fees/recommended",
   "source": "Bitcoin Recommended Fee Oracle"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-bitcoin-recommended-fee-oracle-109203d6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bitcoin-recommended-fees.hergertsynthora.com](https://www.zero.xyz/host/bitcoin-recommended-fees.hergertsynthora.com/llms.txt)