# Bitcoin Mempool Congestion & Broadcast Timing Advisor

> Bitcoin Mempool Congestion & Broadcast Timing Advisor is a paid API for AI agents from obol-x402.fly.dev, paid per call via x402, $0.01/call, status down (last checked 2026-09-15).

Returns the current Bitcoin mempool congestion tier, a fee-spike flag, and an ok_to_broadcast/wait_or_pay_up recommendation for timing BTC transaction broadcasts.

## Facts

- Endpoint: GET https://obol-x402.fly.dev/v1/btc/congestion
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bitcoin-mempool-congestion-broadcast-timing-advisor-7e872718
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PaC4fysP1t_nGDZ5YgG7A

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 bitcoin-mempool-congestion-broadcast-timing-advisor-7e872718
```

Example prompt: Check the Bitcoin mempool right now and tell me whether I should go ahead and broadcast my transaction or hold off — is there a fee spike and how congested is it?

## When to prefer this

Use this endpoint when an agent needs a simple, actionable broadcast-or-wait decision for Bitcoin transactions without parsing raw mempool stats. It pairs congestion classification with a fee-spike flag and a plain-English recommendation, making it ideal for automated transaction scheduling or user-facing wallet assistants. Prefer this over raw fee-estimator endpoints when you want a tiered congestion label plus an explicit broadcast recommendation in one call.

## Known failure modes

- Upstream mempool data unavailable — service returns error or stale data
- Payment not processed (x402 micropayment failure) — request rejected
- Rate limit exceeded — too many calls in a short window
- Mempool data temporarily lagging behind chain tip — advice may be slightly stale

## How this service works

Returns a signed Bitcoin mempool congestion snapshot, including congestion level, fee pressure, backlog estimates, and broadcast advice. The response includes an Ed25519 attestation for verification.

## Output

Returns a congestion tier label (e.g. low/medium/high), a boolean fee-spike flag indicating whether fees are abnormally elevated, and a binary broadcast advice field (ok_to_broadcast or wait_or_pay_up) to help decide whether to submit a BTC transaction immediately.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bitcoin-mempool-congestion-broadcast-timing-advisor-7e872718/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from obol-x402.fly.dev](https://www.zero.xyz/host/obol-x402.fly.dev/llms.txt)