# Mint Token Example

This example demonstrates the detailed process of minting Cashu tokens using CDK, including proper logging setup and comprehensive error handling.

# What This Example Does

  1. Sets up detailed logging for debugging and monitoring
  2. Creates a wallet with memory-based storage
  3. Requests a mint quote from the specified mint
  4. Waits for payment and automatically mints tokens
  5. Creates a sendable token for peer-to-peer transfers

# Key Features

  • Comprehensive logging with filtered output for cleaner debugging
  • Error handling using CDK's error types
  • Automatic token minting upon payment confirmation
  • Token generation ready for sharing with other users

# Code Example

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

use cdk::error::Error;
use cdk::nuts::nut00::ProofsMethods;
use cdk::nuts::CurrencyUnit;
use cdk::wallet::{SendOptions, Wallet};
use cdk::Amount;
use cdk_sqlite::wallet::memory;
use rand::random;
use tracing_subscriber::EnvFilter;

#[tokio::main]
async fn main() -> Result<(), Error> {
    let default_filter = "debug";

    let sqlx_filter = "sqlx=warn,hyper_util=warn,reqwest=warn,rustls=warn";

    let env_filter = EnvFilter::new(format!("{},{}", default_filter, sqlx_filter));

    // Parse input
    tracing_subscriber::fmt().with_env_filter(env_filter).init();

    // Initialize the memory store for the wallet
    let localstore = Arc::new(memory::empty().await?);

    // Generate a random seed for the wallet
    let seed = random::<[u8; 64]>();

    // Define the mint URL and currency unit
    let mint_url = "https://fake.thesimplekid.dev";
    let unit = CurrencyUnit::Sat;
    let amount = Amount::from(10);

    // Create a new wallet
    let wallet = Wallet::new(mint_url, unit, localstore, seed, None)?;

    let quote = wallet.mint_quote(amount, None).await?;
    let proofs = wallet
        .wait_and_mint_quote(
            quote,
            Default::default(),
            Default::default(),
            Duration::from_secs(10),
        )
        .await?;

    // Mint the received amount
    let receive_amount = proofs.total_amount()?;
    println!("Received {} from mint {}", receive_amount, mint_url);

    // Send a token with the specified amount
    let prepared_send = wallet.prepare_send(amount, SendOptions::default()).await?;
    let token = prepared_send.confirm(None).await?;
    println!("Token:");
    println!("{}", token);

    Ok(())
}

# Dependencies

Add these dependencies to your Cargo.toml:

[dependencies]
cdk = { version = "*", default-features = false, features = ["wallet"] }
cdk-sqlite = { version = "*", features = ["wallet"] }
tokio = { version = "1", features = ["full"] }
rand = "0.8"
tracing = "0.1"
tracing-subscriber = { version = "0.3", features = ["env-filter"] }

# Running This Example

  1. Set up logging level (optional):
export RUST_LOG=debug
  1. Run the example:
cargo run

# Expected Output

Received 10 from mint https://fake.thesimplekid.dev
Token:
cashuAeyJ0eXAiOiJib2x0MTEi... [full token string]

# Understanding the Output

  • Received amount: Confirms successful minting of the requested tokens
  • Mint URL: Shows which mint processed the request
  • Token string: A Cashu token that can be shared and redeemed by others

# Logging Features

This example includes structured logging that filters out verbose logs from:

  • sqlx: Database operations
  • hyper_util: HTTP utilities
  • reqwest: HTTP client operations
  • rustls: TLS operations

This provides cleaner output while maintaining debug visibility for CDK operations.

# Error Handling

The example uses CDK's Error type for comprehensive error handling including:

  • Network connectivity issues
  • Mint communication failures
  • Payment processing errors
  • Token generation problems

# Next Steps

← Melt Token →