cdk/crates/cdk

CDK (Cashu Development Kit)

ALPHA This library is in early development, the API will change and should be used with caution.

The core implementation of the Cashu protocol for building wallets and mints. It builds upon the primitives defined in the cashu crate and provides higher-level abstractions for working with the Cashu ecosystem.

Crate Feature Flags

The following crate feature flags are available:

Feature	Default	Description
wallet	Yes	Enable cashu wallet features
mint	Yes	Enable cashu mint wallet features
auth	Yes	Enable blind and clear auth

Implemented NUTs:

See https://github.com/cashubtc/cdk/blob/main/README.md

Components

The crate includes several key modules:

• wallet: Implementation of the Cashu wallet
• mint: Implementation of the Cashu mint
• database: Database abstractions for persistent storage
• payment: Payment processing functionality
• nuts: Implementation of the Cashu NUTs

Usage

Add this to your Cargo.toml:

[dependencies]
cdk = "*"

Example

//! Wallet example with memory store
//! Note: This example requires the "wallet" feature to be enabled (enabled by default)

use std::sync::Arc;
use std::time::Duration;

#[cfg(feature = "wallet")]
use cdk::amount::SplitTarget;
use cdk_sqlite::wallet::memory;
use cdk::nuts::{CurrencyUnit, MintQuoteState};
#[cfg(feature = "wallet")]
use cdk::wallet::Wallet;
#[cfg(feature = "wallet")]
use cdk::wallet::SendOptions;
use cdk::Amount;
use rand::random;
use tokio::time::sleep;

#[tokio::main]
async fn main() {
    #[cfg(feature = "wallet")]
    {
        let seed = random::<[u8; 32]>();

        let mint_url = "https://fake.thesimplekid.dev";
        let unit = CurrencyUnit::Sat;
        let amount = Amount::from(10);

        let localstore = memory::empty().await.unwrap();

        let wallet = Wallet::new(mint_url, unit, Arc::new(localstore), &seed, None).unwrap();

        let quote = wallet.mint_quote(amount, None).await.unwrap();

        println!("Pay request: {}", quote.request);

        loop {
            let status = wallet.mint_quote_state(&quote.id).await.unwrap();

            if status.state == MintQuoteState::Paid {
                break;
            }

            println!("Quote state: {}", status.state);

            sleep(Duration::from_secs(5)).await;
        }

        let receive_amount = wallet
            .mint(&quote.id, SplitTarget::default(), None)
            .await
            .unwrap();

        println!("Minted {:?}", receive_amount);

        // Send the token
        let prepared_send = wallet.prepare_send(Amount::ONE, SendOptions::default()).await.unwrap();
        let token = wallet.send(prepared_send, None).await.unwrap();

        println!("{}", token);
    }
}

See more examples in the examples folder.

Minimum Supported Rust Version (MSRV)

The cdk library should always compile with any combination of features on Rust 1.75.0.

To build and test with the MSRV you will need to pin the below dependency versions:

    cargo update -p async-compression --precise 0.4.3
    cargo update -p zstd-sys --precise 2.0.8+zstd.1.5.5
    cargo update -p flate2 --precise 1.0.35
    cargo update -p home --precise 0.5.5
    cargo update -p zerofrom --precise 0.1.5
    cargo update -p half --precise 2.4.1
    cargo update -p url --precise 2.5.2
    # For wasm32-unknown-unknown target
    cargo update -p triomphe --precise 0.1.11

License

This project is licensed under the MIT License.