Pubky Messenger

A Rust library for secure private messaging using the Pubky protocol. This library provides end-to-end encrypted messaging capabilities with authentication via pkarr recovery files.

Features

• 🔐 End-to-end encrypted messaging using X25519-ECDH
• 🔑 Authentication via pkarr recovery files
• ✅ Message signature verification using Ed25519
• 👥 Profile and contact management
• 🔄 Async/await API using Tokio

Installation

Add this to your Cargo.toml:

[dependencies]
pubky-messenger = "0.1.0"

Usage

Basic Example

use pubky_messenger::{PrivateMessengerClient, PublicKey};
use anyhow::Result;

#[tokio::main]
async fn main() -> Result<()> {
    // Load recovery file
    let recovery_file = std::fs::read("recovery.pkarr")?;
    
    // Create client
    let client = PrivateMessengerClient::from_recovery_file(&recovery_file, "your_passphrase")?;
    
    // Sign in
    client.sign_in().await?;
    
    // Send a message
    let recipient = PublicKey::try_from("recipient_public_key_here")?;
    let message_id = client.send_message(&recipient, "Hello, world!").await?;
    println!("Message sent with ID: {}", message_id);
    
    // Get messages
    let messages = client.get_messages(&recipient).await?;
    for msg in messages {
        println!("{}: {}", msg.sender, msg.content);
    }
    
    Ok(())
}

Creating a Client from Keypair

If you already have a keypair, you can create the client directly:

use pkarr::Keypair;
use pubky_messenger::PrivateMessengerClient;

let keypair = Keypair::random();
let client = PrivateMessengerClient::new(keypair)?;

Working with Profiles

// Get your own profile
if let Some(profile) = client.get_own_profile().await? {
    println!("Name: {}", profile.name);
    println!("Bio: {:?}", profile.bio);
}

// Get followed users
let followed = client.get_followed_users().await?;
for user in followed {
    println!("{}: {}", user.pubky, user.name.unwrap_or_default());
}

API Reference

PrivateMessengerClient

The main client for interacting with the Pubky messaging system.

Methods

• new(keypair: Keypair) -> Result<Self> - Create a new client from a keypair
• from_recovery_file(bytes: &[u8], passphrase: &str) -> Result<Self> - Create from recovery file
• sign_in(&self) -> Result<Session> - Sign in to the homeserver
• send_message(&self, recipient: &PublicKey, content: &str) -> Result<String> - Send encrypted message
• get_messages(&self, other: &PublicKey) -> Result<Vec<DecryptedMessage>> - Get conversation messages
• get_own_profile(&self) -> Result<Option<PubkyProfile>> - Get user's profile
• get_followed_users(&self) -> Result<Vec<FollowedUser>> - Get followed users
• public_key(&self) -> PublicKey - Get the client's public key
• public_key_string(&self) -> String - Get public key as string

Types

• DecryptedMessage - A decrypted message with sender, content, timestamp, and verification status
• PubkyProfile - User profile information (name, bio, image, status)
• FollowedUser - Information about a followed user

Error Handling

All methods return Result<T> where the error type is anyhow::Error. This provides flexible error handling with context. Common error scenarios include:

• Network connectivity issues
• Invalid recovery file or passphrase
• Encryption/decryption failures
• Missing or invalid public keys

Example error handling:

match client.send_message(&recipient, "Hello").await {
    Ok(message_id) => println!("Message sent: {}", message_id),
    Err(e) => eprintln!("Failed to send message: {}", e),
}

Examples

Check the examples/ directory for more detailed examples:

Basic Usage Example

# Run the basic usage example
cargo run --example basic_usage -- path/to/recovery.pkarr [optional_recipient_pubky]

This example demonstrates:

• Loading a recovery file and signing in
• Displaying your profile information
• Listing followed users
• Sending a test message (if recipient pubky provided)
• Reading conversation messages

Send Message Example

# Send a message to a specific pubky
cargo run --example send_message -- path/to/recovery.pkarr recipient_pubky "Your message here"

# Example:
cargo run --example send_message -- recovery.pkarr pk:q9x5sfjbpajdebk45b9jashgb86iem7rnwpmu16px3ens63xzwro "Hello there!"

This example:

• Takes a recovery file, recipient pubky, and message as arguments
• Signs in to Pubky
• Sends the message to the specified recipient
• Displays the message ID and timestamp

Read Messages Example

# Read all messages from a conversation with a specific pubky
cargo run --example read_messages -- path/to/recovery.pkarr peer_pubky

# Example:
cargo run --example read_messages -- recovery.pkarr pk:q9x5sfjbpajdebk45b9jashgb86iem7rnwpmu16px3ens63xzwro

This example:

• Takes a recovery file and peer pubky as arguments
• Signs in to Pubky
• Fetches all messages from the conversation
• Displays messages in a formatted, chronological order
• Shows sender information, timestamps, and verification status

Real-time Conversation Example

# Start an interactive chat session with a specific pubky
cargo run --example conversation -- path/to/recovery.pkarr peer_pubky

# Example:
cargo run --example conversation -- recovery.pkarr pk:q9x5sfjbpajdebk45b9jashgb86iem7rnwpmu16px3ens63xzwro

This example provides a real-time chat experience:

• Shows the last 10 messages when starting
• Allows you to type and send messages interactively
• Automatically checks for new messages every 3 seconds
• Displays messages with timestamps in HH:MM:SS format
• Press Ctrl+C to exit the chat session

Features:

• Real-time message polling
• Interactive terminal UI
• Message history display
• Automatic new message detection
• Clean, chat-like interface

Security

This library implements end-to-end encryption using:

• X25519-ECDH for key agreement
• ChaCha20-Poly1305 for message encryption (via pubky-common)
• Ed25519 for message signatures
• Blake3 for hashing

Messages are encrypted with a shared secret derived from the sender and recipient's keypairs.

License

MIT