# Satoshi API - Bitcoin Next Block Fee Intelligence

> Satoshi API - Bitcoin Next Block Fee Intelligence is a paid API for AI agents from bitcoinsapi.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns live fee rates, transaction count, and cost data for the next Bitcoin block to help apps and AI agents decide when to send Bitcoin transactions.

## Facts

- Endpoint: POST https://bitcoinsapi.com/api/v1/mining/nextblock
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/satoshi-api-bitcoin-next-block-fee-intelligence-d2e8437e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nzGqPbT1mE0THWLONhve7

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 satoshi-api-bitcoin-next-block-fee-intelligence-d2e8437e -d '<json body>'
```

Example prompt: What are the current Bitcoin fee rates for the next block — specifically the median, min, and max sat/vbyte — so I can decide whether to send my transaction now or wait?

## When to prefer this

Use this endpoint when you need real-time Bitcoin mempool fee intelligence specifically for next-block inclusion decisions. Prefer this over generic blockchain explorers when you need structured fee data (median, min, max, top transactions) in a single call optimized for programmatic use by apps or AI agents. Ideal for wallets, payment automation, and any agent that needs to decide whether to send Bitcoin now or defer.

## Known failure modes

- Network or node connectivity issues returning 5xx errors
- Mempool data temporarily unavailable during node sync
- Stale or delayed fee data if the Bitcoin node is behind tip
- Invalid or malformed request body returning 400 errors
- Rate limiting or payment failures if x402 payment not included

## How this service works

Know when to send Bitcoin and when to wait. Satoshi API gives apps and AI agents live fee recommendations, mempool context, and cost estimates. Free, open source.

## Output

A JSON object containing the projected next block's height, transaction count, median/min/max fee rates in sat/vbyte, total fees in BTC, and an array of the top 5 transactions by fee rate with their txid and fee rate.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "schema": {
  "type": "object",
  "required": [
   "height",
   "tx_count",
   "median_fee_rate"
  ],
  "properties": {
   "top_5": {
    "type": "array"
   },
   "height": {
    "type": "integer"
   },
   "tx_count": {
    "type": "integer"
   },
   "max_fee_rate": {
    "type": "number"
   },
   "min_fee_rate": {
    "type": "number"
   },
   "total_fees_btc": {
    "type": "number"
   },
   "median_fee_rate": {
    "type": "number"
   }
  }
 },
 "example": {
  "top_5": [
   {
    "txid": "example-txid",
    "fee_rate": 122
   }
  ],
  "height": 840000,
  "tx_count": 2800,
  "max_fee_rate": 122,
  "min_fee_rate": 5.1,
  "total_fees_btc": 0.36,
  "median_fee_rate": 14.2
 },
 "mimeType": "application/json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/satoshi-api-bitcoin-next-block-fee-intelligence-d2e8437e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bitcoinsapi.com](https://www.zero.xyz/host/bitcoinsapi.com/llms.txt)