Nigiri

CLI to quickly fire up a a Bitcoin regtest box along with Electrs and Esplora. Includes faucet and push commands.

hal

Bitcoin CLI swiss-army-knife (based on rust-bitcoin).

BitKey

Live USB for airgapped transactions and Bitcoin swiss army knife.

PaperVault

Offline paper-based secret storage using AES-256-GCM and Shamir's Secret Sharing. Create printable encrypted backups of seed phrases with threshold key splitting.

Pycoin

Python-based Bitcoin and alt-coin utility library.

bx

Bitcoin Command Line Tool.

txwatcher

A little Python utility that lets you monitor Bitcoin addresses through Blockchain Websocket API and perform custom callbacks.

hellobitcoin

A collection of simple programs which can generate bitcoin wallets, create and sign transactions, and send transactions over the bitcoin network.

Mining visualization

HD Wallet Scanner

Find all used addresses in your Bitcoin HD wallets bypassing gap limits.

<qr-code>

A no-framework, no-dependencies, customizable, animate-able, SVG-based <qr-code> web component.

Bitcoin Serverless Donations

Self-custodial serverless donation widget with address rotation derived from an XPUB.

BTC Tooling

Bitcoin dashboard with real-time price data, a chart, orderbook, market summary, Twitter/X insights, and halving countdown data. Live Demo

Chartscout

Real-time BTC chart pattern detection and trading alerts across multiple exchanges.

Bitcoin Bottom Score

Real-time Bitcoin cycle bottom probability tracker. Aggregates 25 on-chain and macro signals (MVRV Z-Score, Puell Multiple, Hash Ribbon, ETF flows) into a daily P(bottom) score. Free, updated twice daily.

BTC Airgap Bridge

100% client-side tool for broadcasting signed Bitcoin transactions from air-gapped wallets.

SuperScalar MCP

MCP server for SuperScalar Bitcoin Lightning channel factories — onboard N users in one shared UTXO, no soft fork required.

Lightning Memory

Open-source memory layer for AI agents in the Bitcoin/Lightning economy. L402 payment gateway, vendor reputation, spending anomaly detection.

CryptoCalk

Bitcoin profitability and on-chain calculators: ASIC/GPU mining ROI, hash rate converter, halving countdown, Mayer Multiple, Stock-to-Flow (S2F), Rainbow chart, profit/loss, DCA simulator, tax estimator, liquidation price. Client-side, no signup, available in 6 languages.

Freedom Clock

Bitcoin-aware FIRE calculator with sell, borrow, and borrow-then-sell spend models. Converts savings and BTC holdings into years of financial freedom. Fully local, no account, MIT. Also an open-source e-ink desk device (~$30).

dont-trust-verify

Bitcoin-only client-side tools and self-custody education: 22 calculators, validators and decoders (BIP-39 validator, tx-stuck checker, fee estimator, wallet installer SHA-256 verifier, self-custody score quiz), plus primary-sourced guides and hardware wallet reviews. No signup, no tracking, EN +…

BackPoW

Solo block odds, cost of production and break-even electricity per rig, from live difficulty.

3xpl.com

Fastest ad-free universal block explorer.

Bitquery.io

Bitquery provides blockchain data, offering real-time streaming APIs for 40+ chains, NFT APIs, and a money flow investigation tool.

block.io

blockchair.com

Universal blockchain explorer and search engine.

BlockCypher

Esplora

Self-hosted blockchain explorer.

Insight

Chain.com

Coinbase Wallet

Chainradar API

Blockchain Explorer API for Chainradar.

One-Time Address

A better way to share your Bitcoin address.

Cryptocurrency Alerting

Bitcoin wallet monitoring and blockchain alerts.

BTC Connect

Unified Bitcoin Layer-1 and Layer-2 wallet connection and account abstraction.

Tatum

The blockchain development platform to build Web3 application. The go-to blockchain data API for Web3 developers.

mempool.space

Open source and self hostable REST, WebSocket and Electrum RPC API

Bitview

An open source Bitcoin Core data extractor and visualizer (aka FOSS Glassnode)

Maestro

A high-performance Bitcoin RPC and UTXO indexer API that powers applications with real-time blockchain data, mempool monitoring, and event notifications.

OnFinality

Bitcoin RPC endpoints and API access for dApps, wallets, analytics, and backend services.

Luganodes RPC

Bitcoin Core JSON-RPC endpoints on dedicated bare-metal infrastructure with a free tier.

CoinGapRadar

Real-time crypto premium tracker across 9 countries. Monitor kimchi premium and regional price gaps. Free, no signup.

CoinMetrics.io

JSON REST API (free as well as paid) with access to market data. Also CSV data file download available.

CoinPaprika

Free crypto market data API. 12,000+ coins, 350+ exchanges, tickers, OHLCV, historical prices. No API key for free tier.

Messari.io

JSON REST API (free as well as paid) with access to market data, news, metrics, profile, etc.

PreReason

Pre-analyzed Bitcoin market briefings via REST API. Covers BTC price, hash rate, difficulty, mining production costs, treasury holdings (30 public companies), and macro signals that move Bitcoin (Fed balance sheet, M2, Treasury yields). Returns trend direction, confidence scores, and regime…

BitGo

Coinbase

Blockchain.com

BIP32

Blue Wallet

CoPay by BitPay

Coinb.in

Coin Wallet

Electrum

Long-standing Python-based Bitcoin wallet with good security features. Private keys are encrypted and do not touch the internet and balance is checked with a watch-only wallet. Compatible with other w…

Green

Sparrow

Sparrow is a Bitcoin wallet for those who value financial self-sovereignty. Sparrow’s emphasis is on security, privacy, and usability. Sparrow does not hide information from you - on the contrary, it…

Wasabi Wallet

An open source, native desktop wallet for Windows, Linux, and MacOS. Wasabi implements trustless CoinJoins over the Tor network. Neither an observer nor the participants can determine which output bel…

Joinmarket

Decentralized CoinJoin implementation

Jam

User friendly frontend for Joinmarket

3xpl.com

Fastest ad-free universal block explorer.

Chain.so

Blockchain.com

Blockchair.com

Universal blockchain explorer and search engine.

Blockstream.info

Blockchain explorer with API (mainnet, testnet and Liquid).

Bitcoin Transaction Explorer

Blockexplorer.com

Smartbit

mempool.space

Open source, self hostable blockchain, mempool and lightning network explorer

libsecp256k1

Optimized C library for EC operations on curve secp256k1

UltrafastSecp256k1

High-performance secp256k1 engine with a stable C ABI, CPU, CUDA, OpenCL, embedded, and WebAssembly targets.

Libbitcoin

Libbitcoin

A set of cross platform C++ libraries for building bitcoin applications

libwally-core

Awesome CryptoCoinJS

Bitcore Library

Pure and powerful Bitcoin library.

Bitcoinjs-lib

A javascript Bitcoin library for node.js and browsers.

Cryptocoin

BlockTrail SDK NodeJS

bcoin

Javascript bitcoin library for node.js and browsers.

Libauth

A lightweight, zero-dependency, JavaScript/TypeScript bitcoin library.

noble-curves

audited implementation of secp256k1 + schnorr in pure typescript

noble-secp256k1

alternative implementation of secp256k1: size is only 4KB gzipped; lots of comments, very valuable for learning how algorithms work

scure-btc-signer

audited & minimal library for creating, signing & decoding Bitcoin transactions. With Schnorr, Taproot, UTXO & PSBT.

bitcoin-sdk-js

Bitcoin TypeScript/JavaScript Library for NodeJS, Browser and Mobile. Segwit & Taproot support.

toll-booth

HTTP 402 payment middleware for Node.js; gates any API behind Lightning, Cashu, or stablecoin payments with five backend options.

PHP-OP_RETURN

BlockTrail PHP SDK

Bitcoin-ruby

bitcoinrb

Ruby bitcoin library including script interpreter.

bech32rb

Bech32 and Bech32m encode/decode library.

bip-schnorrrb

Schnorr signature library for Bitcoin.

Bitcoin Dev Kit (BDK)

With BDK, you can seamlessly build cross platform mobile wallets

Rust Bitcoin

support for de/serialization, parsing and executing on data-structures and network messages.

Lightning Dev Kit (LDK)

Complete Lightning implementation packaged as an SDK

Bithoven

A High-Level, Imperative Language for Bitcoin Smart Contracts, featuring an LR(1) parser with static analysis for compile-time safety.

BlockTrail SDK Python

btctxstore

Simple library to store/retrieve information in bitcoin transactions using OP_RETURN.

pybitcointools

Python library for Bitcoin signatures and transactions from Vitalik Buterin. Project discontinued.

Pycoin

Python-based Bitcoin and alt-coin utility library.

bitcoin_tools

Python library for building and analyzing transactions and scripts (both standard and custom). Comes along with a UTXO set analysis tool. Includes several examples and exhaustive documentation.

pybtc

Python BTC is an experimental project that aims to provide human-friendly interfaces for common BTC operations.

BitcoinJ

XChange

Library that provides a simple and consistent API for interacting with 50+ Bitcoin currency exchanges.

Bitcoin Spring Boot Starter

Bitcoin integration for Spring Boot applications.

bech32

Bech32 and Bech32m encode/decode library.

Bitcoin-S

Scala/JVM toolkit for Bitcoin applications, includes Bitcoin data structures, transaction signing, strongly typed bitcoind/Eclair RPC clients, and more.

secp256k1.swift

Swift package for secp256k1 applications, includes Elliptic Curve operations, Schnorr, ZKP and more for Bitcoin.

NBitcoin

Comprehensive Bitcoin library for the .NET framework.

BitcoinLib

The most complete, up-to-date, battle-tested .net Library and RPC Wrapper for Bitcoin and Altcoins in C#.

Haskoin-core

Haskoin Core is a library of Bitcoin and Bitcoin Cash functions written in Haskell.

Script Playground

Bitcoin IDE

Bitcoin Script for dummies.

Script Debugger

Bitcore Playground

Mnemonic Code generator

blockchain-demo

A web-based demonstration of blockchain concepts.

Bitcoin Script Debugger

Visualize Bitcoin script execution for real transactions.

Bitauth IDE

An interactive development environment for Bitcoin contracts.

ChainQuery Bitcoin RPC

Run select bitcoin RPC API calls and read full RPC docs in your browser.

Bithoven IDE

Web IDE for Bithoven, A High-Level, Imperative Language for Bitcoin Smart Contracts.

Raw transaction decoder

Paste a raw Bitcoin transaction (legacy, SegWit or Taproot) and see every byte named: scripts disassembled, addresses derived, witness and sequence fields explained. Runs in the browser, no server.

BitcoinDatabaseGenerator

A high performance data transfer tool that can be used to copy data from Bitcoin Core blockchain files to a SQL Server database.

Blockparser+SQL

Fast, quick and dirty bitcoin blockchain parser.

BitcoinABE

Abe: block browser for Bitcoin and similar currencies.

Chaingraph

A multi-node blockchain indexer and GraphQL API.

nodsig

Turns your node's blocks into sealed local artifacts: chain questions become offline lookups, and every answer carries a fingerprint anyone can recompute. Python stdlib only.

btcd

Go-based full node since 2013.

Bitcoin-ruby-node

bitcoin node based on bitcoin-ruby-blockchain.

Fullnode

Javascript implementation of bitcoin.

Bitcore Node

bitcoind linked to node.js by BitPay.

Bitcore Library

Pure and powerful Bitcoin library.

Bitcoin Core

direct descendant of the original Bitcoin implementation in C++

A Gentle Introduction to Bitcoin Core Development

Mastering Bitcoin

Mastering Bitcoin 3rd Edition - Programming the Open Blockchain

Grokking Bitcoin

An in-depth technical book with rich illustrations.

Bitcoin Book of BIPs

Deployed and complete BIPs, grouped by theme. PDF, ePUB, and web.

Bitcoin Stackexchange

Elliptic Curve Cryptography A Gentle Introduction

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Bitcoin Programming with BitcoinJS and Bitcoin Core CLI

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Bitcoin Protocol Development Curriculum - Chaincode Labs

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Lightning Network Protocol Development Curriculum - Chaincode Labs

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btcinformation.org / Developer Documentation

Find useful resources, guides and reference material for developers.

Bitcoin & Cryptocurrency

.

@lopp / Bitcoin Developers

Software developers who have experience working on Bitcoin implementations or applications.

@lopp / Lightning Developers

Software developers with experience working on LN implementations / applications.

Practical Bitcoin Info - Google Sheets

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A brief history of Bitcoin development...

bitcoin-resources.com

Meta-list of Bitcoin resources, from books, articles, to podcasts.

Jameson Lopp Bitcoin Resource List

Very detailed curated Bitcoin resource list and meta-list by J. Lopp

Svrgnty.com: Everything Bitcoin

A curated list of the best Bitcoin resources.

River Learn

A collection of educational resources to learn about Bitcoin basics, investing, technology, and more.

BitcoinCompanies

Corporate Bitcoin treasury map and leaderboard with claimed vs verified holdings.

Learn me a Bitcoin - Greg Walker

extensive learning resource for bitcoin developers

Bennet.org

Interactive technical guides for bitcoiners.

Knowing Bitcoin

Comprehensive Bitcoin education with 214+ in-depth guides on Lightning Network, wallets, security, privacy, and nodes.

Bitcoin.diy

Bitcoin-only education and hardware wallet reviews, focused on self-custody for beginners and intermediate users.

LearnBitcoin.com

Bitcoin-only education: a guided six-chapter journey, 17 long-form rabbit holes, and a ~470-entry glossary, CC-BY-SA with no ads or affiliates.

Bitcoin Institute

Bilingual (EN/JP) archive of Satoshi Nakamoto primary sources: forum posts, emails, and mailing-list messages, each linked to its original source.