Libraries & SDKs
You don't need to implement the Bitcoin protocol from scratch. Mature libraries exist for every major programming language, handling key generation, transaction construction, signing, and network communication.
Choosing a Library
| Language | Library | Best For |
|---|---|---|
| JavaScript/TypeScript | bitcoinjs-lib, BDK-JS | Web wallets, browser extensions, Node.js apps |
| Python | python-bitcoinlib, BDK-Python | Scripting, prototyping, backend services |
| Rust | BDK, LDK, rust-bitcoin | High-performance wallets, Lightning, production systems |
| Go | btcd/btcutil, btcwallet | Infrastructure, backend services |
The BDK Ecosystem
The Bitcoin Dev Kit (BDK) deserves special mention. It's a modular Rust library with bindings for multiple languages, designed to be the "right way" to build Bitcoin wallets:
- bdk_wallet — High-level wallet with descriptor support
- bdk_esplora — Blockchain data via Esplora API
- bdk_electrum — Blockchain data via Electrum servers
- bdk_file_store — Persistent wallet storage
BDK handles the hard parts (coin selection, fee estimation, PSBT construction) so you can focus on your application logic.
The LDK Ecosystem
Lightning Dev Kit (LDK) is a flexible Lightning Network library:
- Build custom Lightning wallets and nodes
- Integrate Lightning into existing applications
- Available in Rust with bindings for other languages
Language-Specific Guides
- JavaScript / TypeScript — bitcoinjs-lib, BDK-JS
- Python — python-bitcoinlib, BDK-Python
- Rust — BDK, LDK, rust-bitcoin
- Go — btcd, btcutil
Common Patterns Across Libraries
Regardless of language, Bitcoin libraries typically follow similar patterns:
1. Key Generation
Generate entropy → Derive mnemonic → Derive master key → Derive child keys
2. Address Creation
Private key → Public key → Hash → Encode (bech32/base58) → Address
3. Transaction Construction
Select UTXOs → Build inputs/outputs → Calculate fee → Sign → Broadcast
4. PSBT Workflow
PSBT (BIP-174) is the standard format for partially signed transactions, enabling multi-party signing:
Creator → Updater → Signer(s) → Combiner → Finalizer → Extractor
This is the modern way to handle transactions that require multiple signatures or hardware wallet interaction.