Download the App

C3 is available for both iOS and Android devices. Download from your preferred app store:

Download on the

App Store

Get it on

Google Play

Using beta backend? Download the beta app: TestFlight (iOS) or Open Beta (Android)

System Requirements

iOS: iOS 15.1 or later
Android: Android 7.0 (API 24) or later

First Launch

When you open C3 for the first time, you'll be guided through the initial setup:

Welcome Screen

The app displays a welcome screen with options to set up your first server connection. You can scan a QR code or enter details manually.

Permission Requests

The app may request the following permissions:

Camera — For scanning QR codes
Notifications — For permission request alerts
Local Network — For discovering servers (iOS)

Server Connection

Connect to your C3 backend using QR code or manual configuration. See the Local Setup or Remote Setup guides for detailed instructions.

Connecting to Server

There are two ways to connect to your C3 backend:

1. QR Code (Recommended)

The fastest method. Tap "Scan QR Code" and point your camera at the QR code displayed in your terminal when you start the C3 server. See the Local Setup Guide for detailed instructions.

2. Manual Configuration

Enter connection details manually in Settings → Add Server Profile:

Server URL	IP:port (e.g., `192.168.1.100:8883`) or ngrok URL
Username	Your configured username (required)
Password	Your configured password (required)
SSL	Off for local, On for ngrok

Creating / Opening Your First Project

Once connected, you need to create a project or open an existing one to start a coding session:

Tap "Open Project"

From the Projects screen, tap the "+" button to open the project modal.

Select Server Profile

Choose which server profile to use for this project. The app will detect your system's path format (macOS, Windows, or Linux) to help you enter the correct directory path.

Enter Project Details

Directory Path: The absolute path on your computer where the project lives. You can type it manually, use the folder browser, or clone from GitHub.
Project Name: A friendly name for your project
Description: Optional description of your project
Enable Git Worktrees: When enabled, each chat session works in an isolated git branch, preventing conflicts when running multiple sessions

Start Chatting

Tap "Create" to save the project, then tap on it to open. C3 will start a session with your selected AI agent in that directory. You can switch between Claude Code, OpenCode, or Codex using the provider switcher in the toolbar.

Project Paths

Use full absolute paths to your project directory. The app will show example paths based on your server's operating system: /Users/you/projects/my-app for macOS, C:\Users\you\projects\my-app for Windows, or /home/you/projects/my-app for Linux.

Directory Creation

If the specified directory doesn't exist on your machine, it will be automatically created when you send your first message in the chat.

App Settings

Customize your C3 experience through the Settings screen:

Appearance

Theme — Choose between Light, Dark, or System theme

Haptic Feedback

Vibration Feedback — Enable/disable subtle vibrations when interacting with the app

Server Profiles

Manage multiple server connections. Each profile includes:

Profile Name — A friendly name for the server
Server URL — The backend server address
Credentials — Username and password for authentication
SSL/TLS — Enable secure WebSocket connection (wss://)
Backend Version — Shows the connected backend version with update check
OpenCode — Enable/disable OpenCode support and manage models Beta
Codex — Enable/disable Codex support and manage models Beta

Per-Profile Notifications

Each server profile has its own notification settings:

All Messages — Get notified for every message from the AI agent
Needs Attention — Get notified when the agent needs your input (e.g., permission requests)

QR Code Setup

You can quickly add or update a server profile by scanning the QR code displayed when you start the C3 backend. Tap the QR icon in the Server Profiles section header.

Security Guide

Access the in-app security guide to learn best practices for using C3 securely.

Rate Us

If you're enjoying C3, leave a review on the App Store or Google Play to help others discover the app.