Mempool

API

Bitcoin Mempool & Transaction Fee API Service

Overview

The Mempool API provides real-time Bitcoin mempool statistics and transaction fee data. Core endpoints include /fees/recommended (fast/medium/slow fee estimates), /mempool/summary (current size, unconfirmed tx count), and /transactions/{txid} (detailed transaction info). Responses are JSON-formatted. Ideal for wallet developers integrating optimal fee suggestions, blockchain analysts tracking mempool congestion, and users monitoring tx statuses. Public endpoints require no auth, though rate limits apply to prevent abuse, supporting fee-aware Bitcoin app development efficiently.

Example Integration (JavaScript)

script.js JS


fetch('https://mempool.space/api')
  .then(res => res.json())
  .then(data => console.log(data))
  .catch(err => console.error(err));

Key Features

RESTful
JSON support
No Auth required
Real-time mempool data
Transaction fee estimates

Frequently Asked Questions

? Is Mempool free to use?

Yes, the public API endpoints are free to use without authentication, though rate limits apply for high-volume requests.

? Does it require an API Key?

No, the public Mempool API does not require an API key for standard usage.

? What is the response format?

All responses from the Mempool API are in JSON format, making it easy to parse for developers.

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Tool Info

Pricing Free

Category Cryptocurrency

Platform Public API

Pros

⊕ Easy to integrate
⊕ Free public access
⊕ Comprehensive transaction fee data
⊕ Trusted and reliable service

Cons

⊖ Rate limited for high-volume requests
⊖ Bitcoin-only (no other crypto support)
⊖ Limited advanced features in public tier