BDK

A modern, lightweight, descriptor-based wallet library written in Rust!

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About

The bdk library aims to be the core building block for Bitcoin wallets of any kind.

• It uses Miniscript to support descriptors with generalized conditions. This exact same library can be used to build single-sig wallets, multisigs, timelocked contracts and more.
• It supports multiple blockchain backends and databases, allowing developers to choose exactly what's right for their projects.
• It's built to be cross-platform: the core logic works on desktop, mobile, and even WebAssembly.
• It's very easy to extend: developers can implement customized logic for blockchain backends, databases, signers, coin selection, and more, without having to fork and modify this library.

Examples

Sync the balance of a descriptor

use bdk::Wallet;use bdk::database::MemoryDatabase;use bdk::blockchain::{noop_progress,ElectrumBlockchain};use bdk::electrum_client::Client;fnmain() -> Result<(), bdk::Error>{let client = Client::new("ssl://electrum.blockstream.info:60002")?;let wallet = Wallet::new("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
bitcoin::Network::Testnet,MemoryDatabase::default(),ElectrumBlockchain::from(client))?;
wallet.sync(noop_progress(),None)?;println!("Descriptor balance: {} SAT", wallet.get_balance()?);Ok(())}

Generate a few addresses

use bdk::{Wallet, database::MemoryDatabase};use bdk::wallet::AddressIndex::New;fnmain() -> Result<(), bdk::Error>{let wallet = Wallet::new_offline("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
bitcoin::Network::Testnet,MemoryDatabase::default(),)?;println!("Address #0: {}", wallet.get_address(New)?);println!("Address #1: {}", wallet.get_address(New)?);println!("Address #2: {}", wallet.get_address(New)?);Ok(())}

Create a transaction

use bdk::{FeeRate,Wallet};use bdk::database::MemoryDatabase;use bdk::blockchain::{noop_progress,ElectrumBlockchain};use bdk::electrum_client::Client;use bdk::wallet::AddressIndex::New;use bitcoin::consensus::serialize;fnmain() -> Result<(), bdk::Error>{let client = Client::new("ssl://electrum.blockstream.info:60002")?;let wallet = Wallet::new("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
bitcoin::Network::Testnet,MemoryDatabase::default(),ElectrumBlockchain::from(client))?;
wallet.sync(noop_progress(),None)?;let send_to = wallet.get_address(New)?;let(psbt, details) = {letmut builder = wallet.build_tx();
builder
.add_recipient(send_to.script_pubkey(),50_000).enable_rbf().do_not_spend_change().fee_rate(FeeRate::from_sat_per_vb(5.0));
builder.finish()?
};println!("Transaction details: {:#?}", details);println!("Unsigned PSBT: {}", base64::encode(&serialize(&psbt)));Ok(())}

Sign a transaction

use bdk::{Wallet,SignOptions, database::MemoryDatabase};use bitcoin::consensus::deserialize;fnmain() -> Result<(), bdk::Error>{let wallet = Wallet::new_offline("wpkh([c258d2e4/84h/1h/0h]tprv8griRPhA7342zfRyB6CqeKF8CJDXYu5pgnj1cjL1u2ngKcJha5jjTRimG82ABzJQ4MQe71CV54xfn25BbhCNfEGGJZnxvCDQCd6JkbvxW6h/0/*)",Some("wpkh([c258d2e4/84h/1h/0h]tprv8griRPhA7342zfRyB6CqeKF8CJDXYu5pgnj1cjL1u2ngKcJha5jjTRimG82ABzJQ4MQe71CV54xfn25BbhCNfEGGJZnxvCDQCd6JkbvxW6h/1/*)"),
bitcoin::Network::Testnet,MemoryDatabase::default(),)?;let psbt = "...";letmut psbt = deserialize(&base64::decode(psbt).unwrap())?;let finalized = wallet.sign(&mut psbt,SignOptions::default())?;Ok(())}

Testing

Unit testing

cargo test

Integration testing

Integration testing require testing features, for example:

cargo test --features test-electrum

The other options are test-esplora or test-rpc. Note that electrs and bitcoind binaries are automatically downloaded (on mac and linux), to specify you already have installed binaries you must use --no-default-features and provide BITCOIND_EXE and ELECTRS_EXE as environment variables.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.