feat: chat cli demo app (#87)

* chore: remove ffi from double ratchet

* chore: format

* feat: chat cli demo app via file transport

* chore: fix the compile issues

* chore: fix long intro copy to clipboard

* chore: move chat cli to bin folder

* chore: use tmp data folder

* chore: update doc

* chore: use encrypted db with default db pass

* chore: fmt and clippy

* chore: fix clippy and refactor

* chore: utils for helper funcs

* chore: rename sessions to chats

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "core/storage",
     "crates/client",
     "crates/client-ffi",
+    "bin/chat-cli",
 ]
 
 [workspace.dependencies]

bin/chat-cli/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "chat-cli"
+version = "0.1.0"
+edition = "2024"
+
+[[bin]]
+name = "chat-cli"
+path = "src/main.rs"
+
+[dependencies]
+libchat = { path = "../../core/conversations" }
+ratatui = "0.29"
+crossterm = "0.29"
+anyhow = "1.0"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+hex = "0.4"
+arboard = "3"

bin/chat-cli/README.md

@@ -0,0 +1,117 @@
+# Chat CLI
+
+A terminal chat application based on libchat library.
+
+## Features
+
+- End-to-end encrypted messaging using libchat
+- File-based transport for local simulation (no network required)
+- Persistent storage (SQLite + JSON state)
+- Multiple chat support with chat switching
+
+## Usage
+
+Run two instances with different usernames in separate terminals:
+
+### Terminal 1 (Alice)
+
+```bash
+cargo run -p chat-cli -- alice
+```
+
+### Terminal 2 (Bob)
+
+```bash
+cargo run -p chat-cli -- bob
+```
+
+### Establishing a Connection
+
+1. In Alice's terminal, type `/intro` to generate an introduction bundle
+2. Copy the intro string
+3. In Bob's terminal, type `/connect alice <intro>` (paste Alice's intro bundle)
+4. Bob can now send messages to Alice
+5. Alice will see Bob's initial "Hello!" message and can reply
+
+### Commands
+
+| Command | Description |
+|---------|-------------|
+| `/help` | Show available commands |
+| `/intro` | Generate and display your introduction bundle |
+| `/connect <user> <intro>` | Connect to a user using their introduction bundle |
+| `/chats` | List all your established chats |
+| `/switch <user>` | Switch to a different chat |
+| `/delete <user>` | Delete a chat (removes session and crypto state) |
+| `/peers` | List transport-level peers (users with inbox directories) |
+| `/status` | Show connection status and your address |
+| `/clear` | Clear current chat's message history |
+| `/quit` or `Esc` or `Ctrl+C` | Exit the application |
+
+#### `/peers` vs `/chats`
+
+- **`/peers`**: Shows users whose CLI has been started (have inbox directories). These are potential contacts you *could* message.
+- **`/chats`**: Shows users you have an **encrypted session** with (via `/connect`). These are active conversations.
+
+### Sending Messages
+
+Simply type your message and press Enter. Messages are automatically encrypted and delivered via file-based transport.
+
+## How It Works
+
+### File-Based Transport
+
+Messages are passed between users via files in a shared directory:
+
+1. Each user has an "inbox" directory at `tmp/chat-cli-data/transport/<username>/`
+2. When Alice sends a message to Bob, it's written as a JSON file in Bob's inbox
+3. Bob's client watches for new files and processes incoming messages
+4. Files are deleted after processing
+
+### Storage
+
+Data is stored in the `tmp/chat-cli-data/` directory:
+
+| File | Purpose |
+|------|---------|
+| `<username>.db` | SQLite database for identity keys, inbox keys, chat metadata, and Double Ratchet state |
+| `<username>_state.json` | CLI state: username↔chat mappings, message history, active chat |
+| `transport/<username>/` | Inbox directory for receiving messages |
+
+The sqlite tables can be viewed with app `DB Browser for SQLite`, password is `123456`, config use `SQLCipher 4 defaults`.
+
+## Example Session
+
+```
+# Terminal 1 (Alice)
+$ cargo run -p chat-cli -- alice
+
+/intro
+# Output: logos_chatintro_abc123
+
+# Terminal 2 (Bob)  
+$ cargo run -p chat-cli -- bob
+
+/connect alice logos_chatintro_abc123
+# Connected! Bob sends "Hello!" automatically
+
+# Now type messages in either terminal to chat!
+
+# To see your chats:
+/chats
+# Output: alice (active)
+
+# To switch between chats (if you have multiple):
+/switch alice
+```
+
+## Architecture
+
+```
+chat-cli/
+├── src/
+│   ├── main.rs       # Entry point
+│   ├── app.rs        # Application state and logic
+│   ├── transport.rs  # File-based message transport
+│   └── ui.rs         # Ratatui terminal UI
+```

bin/chat-cli/src/app.rs

@@ -0,0 +1,460 @@
+//! Chat application logic.
+
+use std::collections::HashMap;
+use std::fs;
+use std::path::PathBuf;
+
+use anyhow::{Context, Result};
+use arboard::Clipboard;
+use libchat::{ChatStorage, Context as ChatManager, Introduction, StorageConfig};
+use serde::{Deserialize, Serialize};
+
+use crate::{transport::FileTransport, utils::now};
+
+/// A chat message for display.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DisplayMessage {
+    pub from_self: bool,
+    pub content: String,
+    pub timestamp: u64,
+}
+
+/// Metadata for a chat session (persisted).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ChatSession {
+    pub chat_id: String,
+    pub remote_user: String,
+    pub messages: Vec<DisplayMessage>,
+}
+
+/// App state that gets persisted.
+#[derive(Debug, Default, Serialize, Deserialize)]
+pub struct AppState {
+    /// Map from remote username to chat session.
+    pub chats: HashMap<String, ChatSession>,
+    /// Currently active chat (remote username).
+    pub active_chat: Option<String>,
+}
+
+/// The chat application state.
+pub struct ChatApp {
+    /// The logos-chat manager.
+    pub manager: ChatManager<ChatStorage>,
+    /// File-based transport for message passing.
+    pub transport: FileTransport,
+    /// Our introduction bundle (to share with others).
+    pub intro_bundle: Option<Vec<u8>>,
+    /// Persisted app state.
+    pub state: AppState,
+    /// Global messages (shown when no active chat).
+    pub global_messages: Vec<DisplayMessage>,
+    /// Input buffer.
+    pub input: String,
+    /// Status message.
+    pub status: String,
+    /// Our user name.
+    pub user_name: String,
+    /// Path to state file.
+    state_path: PathBuf,
+}
+
+impl ChatApp {
+    /// Create a new chat application.
+    pub fn new(user_name: &str, data_dir: &PathBuf) -> Result<Self> {
+        // Create database path
+        let db_path = data_dir.join(format!("{}.db", user_name));
+        std::fs::create_dir_all(data_dir)?;
+
+        // Open or create the chat manager with file-based storage
+        let manager = ChatManager::new_from_store(
+            user_name,
+            ChatStorage::new(StorageConfig::Encrypted {
+                path: db_path.to_string_lossy().to_string(),
+                key: "123456".to_string(),
+            })?,
+        )
+        .context("Failed to open ChatManager")?;
+
+        // Create file-based transport
+        let transport =
+            FileTransport::new(user_name, data_dir).context("Failed to create file transport")?;
+
+        // Load persisted state
+        let state_path = data_dir.join(format!("{}_state.json", user_name));
+        let state = Self::load_state(&state_path);
+
+        // Count existing chats
+        let chat_count = state.chats.len();
+        let status = if chat_count > 0 {
+            format!(
+                "Welcome back, {}! {} chat(s) loaded. Type /help for commands.",
+                user_name, chat_count
+            )
+        } else {
+            format!("Welcome, {}! Type /help for commands.", user_name)
+        };
+
+        Ok(Self {
+            manager,
+            transport,
+            intro_bundle: None,
+            state,
+            global_messages: Vec::new(),
+            input: String::new(),
+            status,
+            user_name: user_name.to_string(),
+            state_path,
+        })
+    }
+
+    /// Load state from file.
+    fn load_state(path: &PathBuf) -> AppState {
+        if path.exists()
+            && let Ok(contents) = fs::read_to_string(path)
+            && let Ok(state) = serde_json::from_str(&contents)
+        {
+            return state;
+        }
+        AppState::default()
+    }
+
+    /// Save state to file.
+    fn save_state(&self) -> Result<()> {
+        let json = serde_json::to_string_pretty(&self.state)?;
+        fs::write(&self.state_path, json)?;
+        Ok(())
+    }
+
+    /// Get the current chat session (if any).
+    pub fn current_session(&self) -> Option<&ChatSession> {
+        self.state
+            .active_chat
+            .as_ref()
+            .and_then(|name| self.state.chats.get(name))
+    }
+
+    /// Get the current messages to display.
+    pub fn messages(&self) -> Vec<&DisplayMessage> {
+        if let Some(session) = self.current_session() {
+            session.messages.iter().collect()
+        } else {
+            // Show global messages when no active chat
+            self.global_messages.iter().collect()
+        }
+    }
+
+    /// Create and display our introduction bundle.
+    pub fn create_intro(&mut self) -> Result<String> {
+        let intro = self.manager.create_intro_bundle()?;
+        let bundle_string = String::from_utf8_lossy(&intro).to_string();
+        self.intro_bundle = Some(intro);
+        self.status = "Introduction bundle created. Share it with others!".to_string();
+        Ok(bundle_string)
+    }
+
+    /// Connect to another user using their introduction bundle.
+    pub fn connect(&mut self, remote_user: &str, bundle_str: &str) -> Result<()> {
+        // Check if we already have a chat with this user
+        if self.state.chats.contains_key(remote_user) {
+            return Err(anyhow::anyhow!(
+                "Already have a chat with {}. Use /switch {} to switch to it.",
+                remote_user,
+                remote_user
+            ));
+        }
+
+        let intro = Introduction::try_from(bundle_str.as_bytes())
+            .map_err(|e| anyhow::anyhow!("Invalid bundle: {:?}", e))?;
+
+        let (chat_id, envelopes) = self
+            .manager
+            .create_private_convo(&intro, "👋 Hello!".as_bytes())?;
+
+        // Send the envelopes via file transport
+        for envelope in envelopes {
+            self.transport.send(remote_user, envelope.data)?;
+        }
+
+        // Create new session
+        let mut session = ChatSession {
+            chat_id: chat_id.clone().to_string(),
+            remote_user: remote_user.to_string(),
+            messages: Vec::new(),
+        };
+        session.messages.push(DisplayMessage {
+            from_self: true,
+            content: "👋 Hello!".to_string(),
+            timestamp: now(),
+        });
+
+        self.state.chats.insert(remote_user.to_string(), session);
+        self.state.active_chat = Some(remote_user.to_string());
+        self.save_state()?;
+
+        self.status = format!("Connected to {}!", remote_user);
+        Ok(())
+    }
+
+    /// Switch to a different chat.
+    pub fn switch_chat(&mut self, remote_user: &str) -> Result<()> {
+        if self.state.chats.contains_key(remote_user) {
+            self.state.active_chat = Some(remote_user.to_string());
+            self.save_state()?;
+            self.status = format!("Switched to chat with {}", remote_user);
+            Ok(())
+        } else {
+            Err(anyhow::anyhow!(
+                "No chat with {}. Use /chats to list available chats.",
+                remote_user
+            ))
+        }
+    }
+
+    /// Delete a chat session.
+    pub fn delete_chat(&mut self, remote_user: &str) -> Result<()> {
+        if let Some(_session) = self.state.chats.remove(remote_user) {
+            // TODO delete not implemented in libchat
+            // Also delete from the library's storage
+            // if let Err(e) = self.manager.delete_chat(&session.chat_id) {
+            //     // Log but don't fail - the CLI state is already updated
+            //     self.status = format!("Warning: failed to delete crypto state: {}", e);
+            // }
+
+            // If we deleted the active chat, clear it
+            if self.state.active_chat.as_deref() == Some(remote_user) {
+                // Switch to another chat if available, otherwise clear
+                self.state.active_chat = self.state.chats.keys().next().cloned();
+            }
+
+            self.save_state()?;
+            self.status = format!("Deleted chat with {}", remote_user);
+            Ok(())
+        } else {
+            Err(anyhow::anyhow!(
+                "No chat with {}. Use /chats to list available chats.",
+                remote_user
+            ))
+        }
+    }
+
+    /// Send a message in the current chat.
+    pub fn send_message(&mut self, content: &str) -> Result<()> {
+        let active = self
+            .state
+            .active_chat
+            .clone()
+            .ok_or_else(|| anyhow::anyhow!("No active chat. Use /connect or /switch first."))?;
+
+        let session = self
+            .state
+            .chats
+            .get(&active)
+            .ok_or_else(|| anyhow::anyhow!("Chat session not found"))?;
+
+        let chat_id = session.chat_id.clone();
+        let remote_user = session.remote_user.clone();
+
+        let envelopes = self.manager.send_content(&chat_id, content.as_bytes())?;
+
+        for envelope in envelopes {
+            self.transport.send(&remote_user, envelope.data)?;
+        }
+
+        // Update messages
+        if let Some(session) = self.state.chats.get_mut(&active) {
+            session.messages.push(DisplayMessage {
+                from_self: true,
+                content: content.to_string(),
+                timestamp: now(),
+            });
+        }
+        self.save_state()?;
+
+        Ok(())
+    }
+
+    /// Process incoming messages from transport.
+    pub fn process_incoming(&mut self) -> Result<()> {
+        while let Some(envelope) = self.transport.try_recv() {
+            self.handle_incoming_envelope(&envelope)?;
+        }
+        Ok(())
+    }
+
+    /// Handle an incoming envelope.
+    fn handle_incoming_envelope(
+        &mut self,
+        envelope: &crate::transport::MessageEnvelope,
+    ) -> Result<()> {
+        match self.manager.handle_payload(&envelope.data) {
+            Ok(content) => {
+                let from_user = &envelope.from;
+                let content = content.ok_or(anyhow::anyhow!("Convo not exist"))?;
+                let chat_id = content.conversation_id.clone();
+
+                // Find or create session for this user
+                if !self.state.chats.contains_key(from_user) {
+                    // New chat from someone
+                    let session = ChatSession {
+                        chat_id: chat_id.clone(),
+                        remote_user: from_user.clone(),
+                        messages: Vec::new(),
+                    };
+                    self.state.chats.insert(from_user.clone(), session);
+                    self.state.active_chat = Some(from_user.clone());
+                    self.status = format!("New chat from {}!", from_user);
+                }
+
+                let message = String::from_utf8_lossy(&content.data).to_string();
+                if !message.is_empty()
+                    && let Some(session) = self.state.chats.get_mut(from_user)
+                {
+                    session.messages.push(DisplayMessage {
+                        from_self: false,
+                        content: message,
+                        timestamp: envelope.timestamp,
+                    });
+                }
+
+                self.save_state()?;
+            }
+            Err(e) => {
+                self.status = format!("Error: {}", e);
+            }
+        }
+        Ok(())
+    }
+
+    /// Add a system message to the current chat (for display only).
+    fn add_system_message(&mut self, content: &str) {
+        let msg = DisplayMessage {
+            from_self: true,
+            content: content.to_string(),
+            timestamp: now(),
+        };
+
+        if let Some(active) = &self.state.active_chat.clone()
+            && let Some(session) = self.state.chats.get_mut(active)
+        {
+            session.messages.push(msg);
+            return;
+        }
+        // No active chat - add to global messages
+        self.global_messages.push(msg);
+    }
+
+    /// Handle a command (starts with /).
+    pub fn handle_command(&mut self, cmd: &str) -> Result<Option<String>> {
+        let parts: Vec<&str> = cmd.splitn(2, ' ').collect();
+        let command = parts[0];
+        let args = parts.get(1).copied().unwrap_or("");
+
+        match command {
+            "/help" => {
+                self.add_system_message("── Commands ──");
+                self.add_system_message("/intro - Show your introduction bundle");
+                self.add_system_message("/connect <user> <bundle> - Connect to a user");
+                self.add_system_message("/chats - List all chats");
+                self.add_system_message("/switch <user> - Switch to chat with user");
+                self.add_system_message("/delete <user> - Delete chat with user");
+                self.add_system_message("/peers - List transport peers");
+                self.add_system_message("/status - Show connection status");
+                self.add_system_message("/clear - Clear current chat messages");
+                self.add_system_message("/quit or Esc or Ctrl+C - Exit");
+                Ok(Some("Help displayed".to_string()))
+            }
+            "/intro" => {
+                let bundle = self.create_intro()?;
+                self.add_system_message("── Your Introduction Bundle ──");
+                self.add_system_message(&bundle);
+                let clipboard_msg = match Clipboard::new().and_then(|mut cb| cb.set_text(&bundle)) {
+                    Ok(()) => "Bundle copied to clipboard! Paste with Cmd+V in /connect.",
+                    Err(_) => "Share this bundle with others to connect!",
+                };
+                self.add_system_message(clipboard_msg);
+                Ok(Some("Bundle created and copied to clipboard".to_string()))
+            }
+            "/connect" => {
+                let connect_parts: Vec<&str> = args.splitn(2, ' ').collect();
+                if connect_parts.len() < 2 {
+                    return Ok(Some("Usage: /connect <username> <bundle>".to_string()));
+                }
+                let remote_user = connect_parts[0];
+                let bundle = connect_parts[1];
+                self.connect(remote_user, bundle)?;
+                Ok(Some(format!("Connected to {}", remote_user)))
+            }
+            "/chats" => {
+                let chat_names: Vec<_> = self.state.chats.keys().cloned().collect();
+                if chat_names.is_empty() {
+                    Ok(Some("No chats yet. Use /connect to start one.".to_string()))
+                } else {
+                    self.add_system_message(&format!("── Your Chats ({}) ──", chat_names.len()));
+                    for name in &chat_names {
+                        let marker = if Some(name) == self.state.active_chat.as_ref() {
+                            " (active)"
+                        } else {
+                            ""
+                        };
+                        self.add_system_message(&format!("  • {}{}", name, marker));
+                    }
+                    Ok(Some(format!("{} chat(s)", chat_names.len())))
+                }
+            }
+            "/switch" => {
+                if args.is_empty() {
+                    return Ok(Some("Usage: /switch <username>".to_string()));
+                }
+                self.switch_chat(args)?;
+                Ok(Some(format!("Switched to {}", args)))
+            }
+            "/delete" => {
+                if args.is_empty() {
+                    return Ok(Some("Usage: /delete <username>".to_string()));
+                }
+                self.delete_chat(args)?;
+                Ok(Some(format!("Deleted chat with {}", args)))
+            }
+            "/peers" => {
+                let peers = self.transport.list_peers();
+                if peers.is_empty() {
+                    Ok(Some(
+                        "No peers found. Start another chat-cli instance.".to_string(),
+                    ))
+                } else {
+                    self.add_system_message(&format!("── Peers ({}) ──", peers.len()));
+                    for peer in &peers {
+                        self.add_system_message(&format!("  • {}", peer));
+                    }
+                    Ok(Some(format!("{} peer(s)", peers.len())))
+                }
+            }
+            "/status" => {
+                let chats = self.state.chats.len();
+                let active = self.state.active_chat.as_deref().unwrap_or("none");
+                let status = format!(
+                    "User: {}\nAddress: {}\nChats: {}\nActive: {}",
+                    self.user_name,
+                    hex::encode(self.manager.installation_key().as_bytes()),
+                    chats,
+                    active
+                );
+                Ok(Some(status))
+            }
+            "/clear" => {
+                if let Some(active) = &self.state.active_chat.clone()
+                    && let Some(session) = self.state.chats.get_mut(active)
+                {
+                    session.messages.clear();
+                    self.save_state()?;
+                }
+                Ok(Some("Messages cleared".to_string()))
+            }
+            "/quit" => Ok(None),
+            _ => Ok(Some(format!(
+                "Unknown command: {}. Type /help for commands.",
+                command
+            ))),
+        }
+    }
+}

bin/chat-cli/src/main.rs

@@ -0,0 +1,93 @@
+//! Chat CLI - A terminal chat application using logos-chat.
+//!
+//! This application demonstrates how to use the logos-chat library
+//! with file-based transport for local communication.
+//!
+//! # Usage
+//!
+//! Run two instances with different usernames:
+//!
+//! ```bash
+//! # Terminal 1
+//! cargo run -p chat-cli -- alice
+//!
+//! # Terminal 2
+//! cargo run -p chat-cli -- bob
+//! ```
+//!
+//! Then in alice's terminal:
+//! 1. Type `/intro` to get your introduction bundle
+//! 2. Copy the bundle string
+//!
+//! In bob's terminal:
+//! 1. Type `/connect alice <bundle>` (paste alice's bundle)
+//!
+//! Now bob can send messages to alice, and alice can reply.
+
+mod app;
+mod transport;
+mod ui;
+mod utils;
+
+use std::{env, path::PathBuf};
+
+use anyhow::{Context, Result};
+
+/// Get the data directory (in project folder).
+fn get_data_dir() -> PathBuf {
+    env::current_dir()
+        .unwrap_or_else(|_| PathBuf::from("."))
+        .join("tmp/chat-cli-data")
+}
+
+fn main() -> Result<()> {
+    // Parse arguments
+    let args: Vec<String> = std::env::args().collect();
+    if args.len() < 2 {
+        eprintln!("Usage: {} <username>", args[0]);
+        eprintln!("\nExample:");
+        eprintln!("  Terminal 1: {} alice", args[0]);
+        eprintln!("  Terminal 2: {} bob", args[0]);
+        std::process::exit(1);
+    }
+
+    let user_name = &args[1];
+
+    // Setup data directory in project folder
+    let data_dir = get_data_dir();
+    std::fs::create_dir_all(&data_dir).context("Failed to create data directory")?;
+
+    println!("Starting chat as '{}'...", user_name);
+    println!("Data dir: {:?}", data_dir);
+
+    // Create app
+    let mut app = app::ChatApp::new(user_name, &data_dir).context("Failed to create chat app")?;
+
+    // Initialize terminal UI
+    let mut terminal = ui::init().context("Failed to initialize terminal")?;
+
+    // Main loop
+    let result = run_app(&mut terminal, &mut app);
+
+    // Restore terminal
+    ui::restore().context("Failed to restore terminal")?;
+
+    result
+}
+
+fn run_app(terminal: &mut ui::Tui, app: &mut app::ChatApp) -> Result<()> {
+    loop {
+        // Process incoming messages
+        app.process_incoming()?;
+
+        // Draw UI
+        terminal.draw(|frame| ui::draw(frame, app))?;
+
+        // Handle input
+        if !ui::handle_events(app)? {
+            break;
+        }
+    }
+
+    Ok(())
+}

bin/chat-cli/src/transport.rs

@@ -0,0 +1,138 @@
+//! File-based transport for local chat communication.
+//!
+//! Messages are passed between users via files in a shared directory.
+
+use std::collections::HashSet;
+use std::fs;
+use std::path::{Path, PathBuf};
+
+use anyhow::{Context, Result};
+use serde::{Deserialize, Serialize};
+
+use crate::utils::now;
+
+/// A message envelope for transport.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MessageEnvelope {
+    pub from: String,
+    pub data: Vec<u8>,
+    pub timestamp: u64,
+}
+
+/// File-based transport for local communication.
+pub struct FileTransport {
+    /// Our user name.
+    user_name: String,
+    /// Base directory for transport files.
+    base_dir: PathBuf,
+    /// Our inbox directory.
+    inbox_dir: PathBuf,
+    /// Set of processed message files (to avoid reprocessing).
+    processed: HashSet<String>,
+}
+
+impl FileTransport {
+    /// Create a new file transport.
+    pub fn new(user_name: &str, data_dir: &Path) -> Result<Self> {
+        let base_dir = data_dir.join("transport");
+        let inbox_dir = base_dir.join(user_name);
+
+        // Create our inbox directory
+        fs::create_dir_all(&inbox_dir).context("Failed to create inbox directory")?;
+
+        Ok(Self {
+            user_name: user_name.to_string(),
+            base_dir,
+            inbox_dir,
+            processed: HashSet::new(),
+        })
+    }
+
+    /// Send a message to a specific user.
+    pub fn send(&self, to_user: &str, data: Vec<u8>) -> Result<()> {
+        let target_dir = self.base_dir.join(to_user);
+
+        // Create target inbox if it doesn't exist
+        fs::create_dir_all(&target_dir).context("Failed to create target inbox")?;
+
+        let envelope = MessageEnvelope {
+            from: self.user_name.clone(),
+            data,
+            timestamp: now(),
+        };
+
+        // Write message to a unique file
+        let filename = format!("{}_{}.json", self.user_name, now());
+        let filepath = target_dir.join(&filename);
+
+        let json = serde_json::to_string_pretty(&envelope)?;
+        fs::write(&filepath, json).context("Failed to write message file")?;
+
+        Ok(())
+    }
+
+    /// Try to receive an incoming message (non-blocking).
+    pub fn try_recv(&mut self) -> Option<MessageEnvelope> {
+        // List files in our inbox
+        let entries = match fs::read_dir(&self.inbox_dir) {
+            Ok(e) => e,
+            Err(_) => return None,
+        };
+
+        for entry in entries.flatten() {
+            let path = entry.path();
+
+            // Skip non-json files
+            if path.extension().map(|e| e != "json").unwrap_or(true) {
+                continue;
+            }
+
+            let filename = path
+                .file_name()
+                .and_then(|n| n.to_str())
+                .unwrap_or("")
+                .to_string();
+
+            // Skip already processed files
+            if self.processed.contains(&filename) {
+                continue;
+            }
+
+            // Try to read and parse the message
+            if let Ok(contents) = fs::read_to_string(&path)
+                && let Ok(envelope) = serde_json::from_str::<MessageEnvelope>(&contents)
+            {
+                // Mark as processed and delete
+                self.processed.insert(filename);
+                let _ = fs::remove_file(&path);
+                return Some(envelope);
+            }
+        }
+
+        None
+    }
+
+    /// List available peers (users with inbox directories).
+    pub fn list_peers(&self) -> Vec<String> {
+        let mut peers = Vec::new();
+
+        if let Ok(entries) = fs::read_dir(&self.base_dir) {
+            for entry in entries.flatten() {
+                if entry.path().is_dir()
+                    && let Some(name) = entry.file_name().to_str()
+                    && name != self.user_name
+                {
+                    peers.push(name.to_string());
+                }
+            }
+        }
+
+        peers
+    }
+
+    /// Get our user name.
+    #[allow(dead_code)]
+    pub fn user_name(&self) -> &str {
+        &self.user_name
+    }
+}

bin/chat-cli/src/ui.rs

@@ -0,0 +1,243 @@
+//! Terminal UI using ratatui.
+
+use std::io::{self, Stdout};
+
+use crossterm::{
+    event::{self, Event, KeyCode, KeyEventKind},
+    execute,
+    terminal::{EnterAlternateScreen, LeaveAlternateScreen, disable_raw_mode, enable_raw_mode},
+};
+use ratatui::{
+    Frame, Terminal,
+    backend::CrosstermBackend,
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Modifier, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, List, ListItem, Paragraph, Wrap},
+};
+
+use crate::app::ChatApp;
+
+pub type Tui = Terminal<CrosstermBackend<Stdout>>;
+
+/// Initialize the terminal.
+pub fn init() -> io::Result<Tui> {
+    execute!(io::stdout(), EnterAlternateScreen)?;
+    enable_raw_mode()?;
+    let backend = CrosstermBackend::new(io::stdout());
+    Terminal::new(backend)
+}
+
+/// Restore the terminal to its original state.
+pub fn restore() -> io::Result<()> {
+    disable_raw_mode()?;
+    execute!(io::stdout(), LeaveAlternateScreen)?;
+    Ok(())
+}
+
+/// Draw the UI.
+pub fn draw(frame: &mut Frame, app: &ChatApp) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(3), // Header
+            Constraint::Min(10),   // Messages
+            Constraint::Length(3), // Input
+            Constraint::Length(3), // Status
+        ])
+        .split(frame.area());
+
+    draw_header(frame, app, chunks[0]);
+    draw_messages(frame, app, chunks[1]);
+    draw_input(frame, app, chunks[2]);
+    draw_status(frame, app, chunks[3]);
+}
+
+fn draw_header(frame: &mut Frame, app: &ChatApp, area: Rect) {
+    let title = match app.current_session() {
+        Some(session) => format!(" 💬 Chat: {} ↔ {} ", app.user_name, session.remote_user),
+        None => format!(
+            " 💬 {} (no active chat - use /connect or /chats) ",
+            app.user_name
+        ),
+    };
+
+    let header = Paragraph::new(title)
+        .style(
+            Style::default()
+                .fg(Color::Cyan)
+                .add_modifier(Modifier::BOLD),
+        )
+        .block(Block::default().borders(Borders::ALL));
+
+    frame.render_widget(header, area);
+}
+
+fn draw_messages(frame: &mut Frame, app: &ChatApp, area: Rect) {
+    let remote_name = app
+        .current_session()
+        .map(|s| s.remote_user.as_str())
+        .unwrap_or("Them");
+
+    // Inner width: area minus borders (2) for wrapping long content.
+    let inner_width = area.width.saturating_sub(2) as usize;
+
+    let messages: Vec<ListItem> = app
+        .messages()
+        .iter()
+        .flat_map(|msg| {
+            let (prefix, style) = if msg.from_self {
+                ("You", Style::default().fg(Color::Green))
+            } else {
+                (remote_name, Style::default().fg(Color::Yellow))
+            };
+
+            let prefix_str = format!("{}: ", prefix);
+            let prefix_len = prefix_str.len();
+
+            // Split content into lines that fit within inner_width.
+            let content = &msg.content;
+            if content.is_empty() {
+                return vec![ListItem::new(Line::from(vec![Span::styled(
+                    prefix_str,
+                    style.add_modifier(Modifier::BOLD),
+                )]))];
+            }
+
+            let mut items = Vec::new();
+            let first_line_width = inner_width.saturating_sub(prefix_len).max(1);
+
+            // First line includes the prefix.
+            let (first_chunk, rest) = if content.len() <= first_line_width {
+                (content.as_str(), "")
+            } else {
+                content.split_at(first_line_width)
+            };
+
+            items.push(ListItem::new(Line::from(vec![
+                Span::styled(prefix_str, style.add_modifier(Modifier::BOLD)),
+                Span::raw(first_chunk),
+            ])));
+
+            // Continuation lines are indented to align with content.
+            let indent = " ".repeat(prefix_len);
+            let mut remaining = rest;
+            while !remaining.is_empty() {
+                let chunk_width = inner_width.saturating_sub(prefix_len).max(1);
+                let (chunk, tail) = if remaining.len() <= chunk_width {
+                    (remaining, "")
+                } else {
+                    remaining.split_at(chunk_width)
+                };
+                items.push(ListItem::new(Line::from(vec![
+                    Span::raw(indent.clone()),
+                    Span::raw(chunk),
+                ])));
+                remaining = tail;
+            }
+
+            items
+        })
+        .collect();
+
+    let title = match app.current_session() {
+        Some(session) => format!(" Messages with {} ", session.remote_user),
+        None => " Messages ".to_string(),
+    };
+
+    let messages_widget =
+        List::new(messages).block(Block::default().title(title).borders(Borders::ALL));
+
+    frame.render_widget(messages_widget, area);
+}
+
+fn draw_input(frame: &mut Frame, app: &ChatApp, area: Rect) {
+    // Inner width: area minus borders (2).
+    let inner_width = area.width.saturating_sub(2) as usize;
+    let input_len = app.input.len();
+
+    // Scroll the view so the cursor (end of input) is always visible.
+    let scroll_offset = if input_len >= inner_width {
+        input_len - inner_width + 1
+    } else {
+        0
+    };
+
+    let visible_input = &app.input[scroll_offset..];
+
+    let input = Paragraph::new(visible_input)
+        .style(Style::default().fg(Color::White))
+        .block(
+            Block::default()
+                .title(" Input (Enter to send) ")
+                .borders(Borders::ALL),
+        );
+
+    frame.render_widget(input, area);
+
+    // Place cursor at the visible end of the input.
+    let cursor_x = area.x + (input_len - scroll_offset) as u16 + 1;
+    frame.set_cursor_position((cursor_x, area.y + 1));
+}
+
+fn draw_status(frame: &mut Frame, app: &ChatApp, area: Rect) {
+    let status = Paragraph::new(app.status.as_str())
+        .style(Style::default().fg(Color::Gray))
+        .block(Block::default().title(" Status ").borders(Borders::ALL))
+        .wrap(Wrap { trim: true });
+
+    frame.render_widget(status, area);
+}
+
+/// Handle keyboard events.
+pub fn handle_events(app: &mut ChatApp) -> io::Result<bool> {
+    // Poll for events with a short timeout to allow checking incoming messages
+    if event::poll(std::time::Duration::from_millis(100))?
+        && let Event::Key(key) = event::read()?
+    {
+        if key.kind != KeyEventKind::Press {
+            return Ok(true);
+        }
+
+        match key.code {
+            KeyCode::Esc => return Ok(false),
+            // Handle Ctrl+C
+            KeyCode::Char('c') if key.modifiers.contains(event::KeyModifiers::CONTROL) => {
+                return Ok(false);
+            }
+            KeyCode::Enter if !app.input.is_empty() => {
+                let input = std::mem::take(&mut app.input);
+
+                if input.starts_with('/') {
+                    match app.handle_command(&input) {
+                        Ok(Some(response)) => {
+                            app.status = response;
+                        }
+                        Ok(None) => {
+                            // Quit signal
+                            return Ok(false);
+                        }
+                        Err(e) => {
+                            app.status = format!("Error: {}", e);
+                        }
+                    }
+                } else if app.current_session().is_some() {
+                    if let Err(e) = app.send_message(&input) {
+                        app.status = format!("Send error: {}", e);
+                    }
+                } else {
+                    app.status = "No active chat. Use /connect first.".to_string();
+                }
+            }
+            KeyCode::Char(c) => {
+                app.input.push(c);
+            }
+            KeyCode::Backspace => {
+                app.input.pop();
+            }
+            _ => {}
+        }
+    }
+
+    Ok(true)
+}

bin/chat-cli/src/utils.rs

@@ -0,0 +1,6 @@
+pub fn now() -> u64 {
+    std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap()
+        .as_millis() as u64
+}

core/conversations/src/context.rs

@@ -1,7 +1,7 @@
 use std::sync::Arc;
 use std::{cell::RefCell, rc::Rc};
 
-use crypto::Identity;
+use crypto::{Identity, PublicKey};
 use storage::{ChatStore, ConversationKind};
 
 use crate::{
@@ -77,6 +77,10 @@ impl<S: ChatStore> Context<S> {
         self._identity.get_name()
     }
 
+    pub fn installation_key(&self) -> PublicKey {
+        self._identity.public_key()
+    }
+
     pub fn create_private_convo(
         &mut self,
         remote_bundle: &Introduction,