# Examples

Welcome to the CDK examples collection! These practical examples demonstrate how to build Cashu applications using the Cashu Dev Kit. Each example includes complete, runnable code with detailed explanations.

# Getting Started Examples

# Getting Started

Set up your development environment and create your first CDK application. Perfect introduction to CDK fundamentals.

Key concepts: Installation, project setup, basic wallet creation

# Single Mint Wallet

Complete tutorial building a full-featured wallet that interacts with a single mint. Includes the entire workflow from setup to token transfers.

Key concepts: Complete workflow, payment monitoring, production considerations

# Basic Wallet

Learn the fundamentals of creating a Cashu wallet, minting tokens, and preparing transfers. Simplified version focusing on core concepts.

Key concepts: Wallet creation, token minting, basic transfers

# Mint Token

A comprehensive example with logging and error handling that shows the complete token minting process from quote to final token.

Key concepts: Detailed logging, error handling, production patterns

# Payment Examples

# Melt Token

Convert Cashu tokens back to Lightning payments. Learn how to "melt" your ecash tokens to pay Lightning invoices.

Key concepts: Lightning payments, invoice handling, token redemption

# P2PK (Pay-to-Public-Key)

Create and redeem tokens that are locked to specific public keys, enabling secure and conditional payments.

Key concepts: Cryptographic locks, spending conditions, secure transfers

# BOLT12 Examples

BOLT12 offers provide improved privacy and reusability compared to traditional Lightning invoices.

# BOLT12 Mint Token

Mint tokens using modern BOLT12 offers instead of traditional Lightning invoices.

Key concepts: BOLT12 offers, reusable payments, enhanced privacy

# BOLT12 with Streaming

Handle multiple BOLT12 payments concurrently using CDK's streaming interface for high-volume applications.

Key concepts: Concurrent processing, payment streams, batch operations

# BOLT12 with Custom HTTP

Implement custom HTTP clients for specialized networking requirements like custom timeouts, proxies, or alternative HTTP libraries.

Key concepts: Custom networking, HTTP transports, production deployment

# Advanced Examples

# Proof Selection

Understand how wallets select and manage individual proofs (tokens) for optimal performance and minimal fees.

Key concepts: Proof optimization, denomination management, fee minimization

# Authentication Wallet

Work with mints that require authentication using CAT (Client Authentication Token) or OIDC protocols.

Key concepts: Mint authentication, access tokens, protected operations

# BIP-353 Human Readable Payments

Use human-readable addresses like alice@example.com instead of complex payment codes for better user experience.

Key concepts: DNS-based payments, user-friendly addresses, BOLT12 integration

# Example Categories

# By Use Case

  • Wallet Development: Basic Wallet, Mint Token, Proof Selection
  • Payment Processing: Melt Token, BOLT12 examples, BIP-353
  • Security Features: P2PK, Authentication Wallet
  • High Performance: Streaming, Custom HTTP, Batch Processing

# By Complexity Level

  • Beginner: Basic Wallet, Mint Token
  • Intermediate: P2PK, Melt Token, BOLT12 Mint Token
  • Advanced: Authentication, Streaming, Custom HTTP, BIP-353

# By Network Features

  • Lightning Integration: Melt Token, BOLT12 examples
  • Privacy Features: P2PK, BOLT12, BIP-353
  • Scaling Solutions: Streaming, Proof Selection

# Running the Examples

# Prerequisites

# Install Rust if you haven't already
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Create a new project
cargo new my-cashu-app
cd my-cashu-app

# Basic Dependencies

Add these to your Cargo.toml for most examples:

[dependencies]
cdk = { version = "*", default-features = false, features = ["wallet"] }
cdk-sqlite = { version = "*", features = ["wallet"] }
tokio = { version = "1", features = ["full"] }
rand = "0.8"

# Feature Flags

Some examples require additional features:

# For BOLT12 examples
cdk = { version = "*", features = ["wallet", "bolt12"] }

# For BIP-353 examples  
cdk = { version = "*", features = ["wallet", "bip353"] }

# For authentication examples
cdk = { version = "*", features = ["wallet", "auth"] }

# Testing with Mints

# Development Mints

Most examples use test mints like https://fake.thesimplekid.dev for demonstration purposes.

Getting Started →