# Satoshi API – Bitcoin Fee Observatory Block Stats

> Satoshi API – Bitcoin Fee Observatory Block Stats is a paid API for AI agents from bitcoinsapi.com, paid per call via x402, $0.005/call, status down (last checked 2026-09-15).

Returns Bitcoin mempool block statistics to help apps and AI agents decide when to send Bitcoin and estimate transaction fees.

## Facts

- Endpoint: POST https://bitcoinsapi.com/api/v1/fees/observatory/block-stats
- Price: $0.005/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/satoshi-api-bitcoin-fee-observatory-block-stats-33b3993e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BlziPozLjlQPAJixlw-r2

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-fee-observatory-block-stats-33b3993e -d '<json body>'
```

Example prompt: What does the Bitcoin mempool look like right now — should I send a transaction or wait for fees to come down, and what fee rate would get me confirmed in the next block?

## When to prefer this

Choose this endpoint when your app or agent needs real-time Bitcoin mempool block-level fee intelligence — specifically block statistics and fee rate recommendations — rather than just a simple fee estimate. It is ideal for agents automating Bitcoin payments, wallets that need to advise users on timing, or dashboards requiring live mempool context. Prefer it over generic blockchain explorers when you need structured, AI-agent-friendly fee data at a low per-call cost.

## Known failure modes

- Invalid or malformed request body returns an error response
- Service unavailable during Bitcoin network disruptions or high load
- Rate limiting or payment failure (x402) if the $0.005 USDC per-call payment is not properly included
- Empty or stale mempool data if the node is not fully synced
- Timeout if the mempool is exceptionally large and block stats take too long to compute

## 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 with an 'ok' boolean status and a 'source' field confirming the data origin ('satoshi-api'), along with live block statistics including fee rate recommendations, mempool congestion context, and per-block cost estimates useful for deciding when and at what fee to broadcast a Bitcoin transaction.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "schema": {
  "type": "object",
  "properties": {
   "ok": {
    "type": "boolean"
   },
   "source": {
    "type": "string"
   }
  }
 },
 "example": {
  "ok": true,
  "source": "satoshi-api"
 },
 "mimeType": "application/json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/satoshi-api-bitcoin-fee-observatory-block-stats-33b3993e/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)