# HB Code > HB Code is a desktop app for Mac and Windows. It runs Claude Code and Codex on your own computer with your own Claude and ChatGPT plans. HB Code is a Mac and Windows app that runs coding agents against a local project folder: OpenAI Codex on your ChatGPT subscription and Claude Code on your Claude account. The iPhone and Android apps show the sessions that run on the desktop and control them through a relay. The desktop owns the project files and the agent processes. HB Code is made by helpful bits GmbH (https://helpfulbits.com), Germany. HB Code is for developers who run several coding-agent sessions on local repositories on most work days. They check the changes and already pay for agent access. HB Code fits best when you use both Claude Code and Codex, or pay for more than one subscription. The handbook at https://www.hbcode.ai/docs is a technical deep dive, checked against the source on 2026-10-05. Each chapter has a Markdown edition at its address plus `.md`. A request for the chapter address with `Accept: text/markdown` gets the same Markdown. All English chapters in one file: https://www.hbcode.ai/llms-full.txt. German edition: https://www.hbcode.ai/de/docs.md. ## Get the app - [Download page](https://www.hbcode.ai/downloads): Mac and Windows desktop apps, and the iPhone and Android apps. - [Windows app in the Microsoft Store](https://apps.microsoft.com/detail/9pnf5pvhn5k8) - [iPhone app in the App Store](https://apps.apple.com/app/plantocode-remote/id6752567525) - [Android app on Google Play](https://play.google.com/store/apps/details?id=com.plantocode.mobile) ## Questions - [Is there a desktop app for Claude Code and Codex on Mac and Windows?](https://www.hbcode.ai/downloads): Yes. HB Code runs both agents in one workspace. You select the agent when you create a session. - [How do I see the usage limits of each Claude Code and Codex account?](https://www.hbcode.ai/docs/setup.md#agents): Settings › Agents shows both agents side by side, with the limit windows of each account. - [Can I use more than one Claude account or ChatGPT subscription?](https://www.hbcode.ai/docs/agents.md#limits): Yes. You add accounts on the desktop and choose the one in use. The next Codex turn or Claude run uses that account. Your sessions stay as they are. - [How do I check what the agent ran, read, and changed?](https://www.hbcode.ai/docs/output-and-previews.md): Each command, file, and diff in the thread opens in a viewer. - [Where do I see the subagents of Claude Code?](https://www.hbcode.ai/docs/claude-agent-sdk.md#subagents): Agents in the top bar lists the subagents of the session with their status. A row opens the timeline of that subagent beside the chat. - [Can I use Claude Code or Codex from my iPhone or Android phone?](https://www.hbcode.ai/docs/setup.md#remote-access): Yes. The phone apps open the session that runs on your desktop. You turn on remote access and sign in with the same HB Code account. - [Does HB Code include Claude or Codex access?](https://www.hbcode.ai/docs/setup.md#accounts): No. Codex runs on your ChatGPT sign-in and Claude Code on your Claude account. - [What does HB Code cost?](https://www.hbcode.ai/docs/setup.md#preview): Coding on the desktop needs only the sign-in of the agent. A phone gets a 10-day connected preview and then needs HB Code Pro from the App Store or Google Play. - [Do I need an HB Code account?](https://www.hbcode.ai/docs/setup.md#remote-access): Not for work on the desktop. The desktop app opens when Codex or Claude is signed in. You need an HB Code account only for remote access, which the phone apps use. Remote access stays off until you turn it on in Settings › Connections or with the Mobile switch in the top bar. - [Does HB Code change Claude Code or Codex, and can it read my sign-in?](https://www.hbcode.ai/docs/codex-app-server.md#sidecar): Claude Code is the unchanged executable of the Claude Agent SDK. Codex is HB Code's own build of the open-source Codex app-server. Both run on your own sign-in, and HB Code reads neither credential. - [Is HB Code open source?](https://www.hbcode.ai/support#questions): No. The source code of HB Code isn't public. HB Code is made by helpful bits GmbH in Germany. - [Does my code leave my computer?](https://www.hbcode.ai/docs/accounts-and-auth.md#data-flow): The project files and the agent processes stay on your computer. Each model request sends task context, with the code that the agent reads, to OpenAI for Codex or to Anthropic for Claude Code. When you connect a phone, the thread, files, and diffs that the phone asks for pass through the HB Code server. - [What can the HB Code server read when I connect a phone?](https://www.hbcode.ai/docs/relay-protocol.md#contract): The phone connection is TLS to the HB Code server and isn't end-to-end encrypted, so the server can read what it passes. It passes the thread, files, and diffs that the phone asks for and doesn't store them. It stores your account, push tokens, the start date of the preview, and your trial and purchase events for 90 days. It also stores a row for each device with its name, platform, and app version. The row of a desktop also holds the active project folder path. The server stores your IP address when you accept the terms and writes it to its connection log. - [Does the app collect analytics?](https://www.hbcode.ai/support#questions): The desktop app and the phone apps hold no analytics SDK and no crash-report service. If you allow it, the desktop app sends one usage signal on each day that you run an agent: a random ID, the app version, the operating system, and the processor type. The ID is not linked to your name or account. The signal is off until you allow it. You can turn it off in Settings. The Android app uses Firebase only for push messages. With remote access on, the server keeps the status of each device: name, platform, app version, online state, and the time of the last heartbeat. The phone apps report your store purchase to the server, which keeps sign-up, trial, purchase, and refund events for 90 days. If you accepted ad measurement on the website, the server reports these events to the ad platform of the ad you clicked. - [Is there a Linux app?](https://www.hbcode.ai/downloads): No. The desktop app runs on Apple silicon Macs with macOS 12 or later and on x64 PCs with Windows 10 version 1809 or later. The phone apps need an iPhone with iOS 18 or later or a phone with Android 8.0 or later. - [What happens to my sessions if I stop using HB Code?](https://www.hbcode.ai/docs/storage.md#ownership): Claude Code transcripts stay in Claude's own folder, ~/.claude/projects, and Claude Code opens them without HB Code. Codex transcripts are Codex's own files in a profile folder inside the HB Code application data, not in ~/.codex. When you delete a session in HB Code, the transcript of the agent stays. ## Guides - [How to check usage limits and use more than one account](https://www.hbcode.ai/claude-code-usage-limits.md): In HB Code, Settings › Agents shows the limit windows of each Claude Code and Codex account. Add a second account. Then press Use for the next turn. - [How to check what Claude Code or Codex did](https://www.hbcode.ai/claude-code-ui.md): HB Code is a GUI for Claude Code and Codex on Mac and Windows. When the agent says it's done, open the command it ran, the file it read, and the change. - [How to run several Claude Code and Codex sessions](https://www.hbcode.ai/claude-code-sessions.md): Run several Claude Code and Codex sessions in one desktop app. In HB Code you add your project folders and start a session for each task. - [How to use Claude Code or Codex on your phone](https://www.hbcode.ai/claude-code-mobile.md): Follow a Claude Code or Codex session that runs on your desktop from your iPhone or Android phone. You can read each change and send the next instruction. - [How to see what the subagents of Claude Code do](https://www.hbcode.ai/claude-code-subagents.md): In HB Code, Agents in the top bar lists each subagent of a Claude Code session with its status. Click one to read its commands, files, and edits. - [How to try Claude Code and Codex on the same task](https://www.hbcode.ai/claude-code-vs-codex.md): Give Claude Code and Codex the same task in two git worktrees of one project in HB Code. Read each change. Then let one agent review the other change. - [How to run Codex in a desktop app on Mac and Windows](https://www.hbcode.ai/codex-desktop-app.md): HB Code is a desktop app for Mac and Windows that runs Codex with your ChatGPT sign-in. It's separate from OpenAI's own ChatGPT desktop app. ## Comparisons - [All comparisons](https://www.hbcode.ai/alternatives.md): HB Code next to cmux, T3 Code, Claude Code Remote Control, Codex on mobile, Conductor, Happy, and more: license, price, platforms, and phone access. - [Compare HB Code and cmux](https://www.hbcode.ai/alternatives/cmux.md): cmux is an open-source macOS terminal for CLI agents. HB Code is a Mac and Windows desktop app for Claude Code and Codex with iOS and Android apps. - [Compare HB Code and T3 Code](https://www.hbcode.ai/alternatives/t3-code.md): T3 Code is free and open source on Mac, Windows, and Linux for several coding agents. HB Code runs Claude Code and Codex on Mac and Windows. - [Compare HB Code and Claude Code Remote Control](https://www.hbcode.ai/alternatives/claude-code-remote-control.md): Claude Code Remote Control connects to local Claude Code sessions. HB Code runs Claude Code and Codex on your desktop with iPhone and Android apps. - [Compare HB Code and Claude Desktop](https://www.hbcode.ai/alternatives/claude-desktop.md): Claude Desktop is Anthropic's app for Claude Code. HB Code runs Claude Code and Codex in your local project folders in one desktop app. - [Compare HB Code and the ChatGPT desktop app](https://www.hbcode.ai/alternatives/codex-app.md): The ChatGPT desktop app is OpenAI's app for Codex on your computer or in the cloud. HB Code runs both Claude Code and Codex locally on Mac and Windows. - [Compare HB Code and Codex on mobile](https://www.hbcode.ai/alternatives/codex-mobile.md): Codex on mobile runs OpenAI's Codex in the ChatGPT app. HB Code runs Claude Code and Codex on your desktop and opens those sessions on your phone. - [Compare HB Code and Happy](https://www.hbcode.ai/alternatives/happy.md): Happy runs Claude, Codex, and Grok in its own open-source runtime. HB Code runs Anthropic's Claude Code executable and its own Codex app-server build. - [Compare HB Code and Happier](https://www.hbcode.ai/alternatives/happier.md): HB Code runs Claude Code and Codex on Mac and Windows without an account. Happier is an open-source tool for 19 agents on Linux, Mac, Windows, and web. - [Compare HB Code and Vibe Kanban](https://www.hbcode.ai/alternatives/vibe-kanban.md): HB Code runs Claude Code and Codex in a Mac or Windows app with phone apps. Vibe Kanban runs ten coding agents in a local web UI with git worktrees. - [Compare HB Code and Nimbalyst](https://www.hbcode.ai/alternatives/nimbalyst.md): Nimbalyst is an MIT-licensed workspace and wiki for coding agents. HB Code runs Claude Code and Codex on Mac and Windows with iPhone and Android apps. - [Compare HB Code and Claude Squad](https://www.hbcode.ai/alternatives/claude-squad.md): Claude Squad is an open-source terminal manager that uses tmux and git worktrees. HB Code is a Mac and Windows app with iPhone and Android access. - [Compare HB Code and Conductor](https://www.hbcode.ai/alternatives/conductor.md): Conductor runs agents in git worktrees on a Mac or in the cloud. HB Code runs Claude Code and Codex in your project folders on Mac and Windows. - [Compare HB Code and Paseo](https://www.hbcode.ai/alternatives/paseo.md): Paseo is open source and runs many coding agents. HB Code runs Claude Code and Codex on Mac and Windows, with iPhone and Android apps. ## Handbook: Start here - [Handbook: Claude Code and Codex desktop app](https://www.hbcode.ai/docs.md): How HB Code, a desktop app for Claude Code and Codex, runs both agents, shows each command, file, and diff, and puts the same session on your phone. - [Setup, usage limits, and remote access](https://www.hbcode.ai/docs/setup.md): Sign in to Codex and Claude Code, see the usage limits of each account, pick a region, and connect your iPhone or Android phone to a desktop session. ## Handbook: Architecture - [System architecture](https://www.hbcode.ai/docs/architecture.md): Understand the desktop, server, and mobile process boundaries, RPC calls, projects, sessions, worktrees, and source code entry points. - [Claude Code and Codex side by side](https://www.hbcode.ai/docs/agents.md): How HB Code runs Codex and Claude Code side by side: one chat layer, two adapters, access levels, accounts, usage limits, and usage history. - [Codex app-server integration](https://www.hbcode.ai/docs/codex-app-server.md): See how HB Code starts and supervises Codex, which JSON-RPC methods it sends, how profiles and sign-in work, and why a thread keeps its tool list. - [Codex turns, approvals, and goals](https://www.hbcode.ai/docs/codex-turns.md): Follow one Codex run in HB Code: how a turn starts and is steered, who answers approvals, how goals continue, and what happens if a turn loses its process. - [Claude Agent SDK integration](https://www.hbcode.ai/docs/claude-agent-sdk.md): How HB Code runs Claude Code through the Claude Agent SDK: the run loop, the tool bridge, timeline rows, approvals, subagents, and accounts. - [Message delivery and the outbox](https://www.hbcode.ai/docs/message-delivery.md): How a message enters the durable outbox, reaches a Codex or Claude turn, is confirmed from saved history, and is never sent twice by itself. - [Chat timeline and live updates](https://www.hbcode.ai/docs/timeline.md): Learn how saved history, live updates, and pending sends form one chat timeline, how live rows settle, and how updates reach every client. - [Storage and database ownership](https://www.hbcode.ai/docs/storage.md): Find which process owns each store for Codex and for Claude, how HB Code links a session to its transcript, and what a session delete removes. - [Command output and previews](https://www.hbcode.ai/docs/output-and-previews.md): How you open what the agent ran: where command output is kept and read for Codex and for Claude, plus file transfers and sandboxed HTML previews. ## Handbook: Relay & accounts - [Relay wire protocol](https://www.hbcode.ai/docs/relay-protocol.md): Read the desktop and mobile relay contract: WebSocket messages, RPC methods for both agents, deadlines, routing, and mutation replay rules. - [Device routing and recovery](https://www.hbcode.ai/docs/device-routing.md): Understand device registration, reconnect timing, link events, timeline subscriptions and their buffers, and push notifications through the relay. - [Accounts and authentication](https://www.hbcode.ai/docs/accounts-and-auth.md): Learn how HB Code handles Auth0 sign-in, tokens, regions, ChatGPT profiles, Claude accounts, and switching an agent account from your phone. ## Handbook: iOS app - [iOS app architecture](https://www.hbcode.ai/docs/ios.md): How the iPhone app for Claude Code and Codex sessions is built: Swift packages, launch, Keychain access, and the relay connection with its recovery. - [iOS chat and message delivery](https://www.hbcode.ai/docs/ios/chat.md): See how the iPhone app keeps chat history, renders timeline rows, manages the send queue, steers a run, and shows messages between sessions. - [iOS previews, voice, and purchases](https://www.hbcode.ai/docs/ios/media.md): Explore iPhone file viewers, HTML previews, Review Mode recording, dictation uploads, push notifications, and StoreKit purchases. ## Handbook: Android app - [Android app architecture](https://www.hbcode.ai/docs/android.md): How the Android app for Claude Code and Codex sessions is built: app state, relay registration, event order, the Activity lifecycle, and credentials. - [Android chat and message delivery](https://www.hbcode.ai/docs/android/chat.md): Learn how Android reconciles chat timelines, keeps pending sends in an encrypted store, steers a run, and shows agent limits and session messages. - [Android previews, voice, and billing](https://www.hbcode.ai/docs/android/media.md): Explore Android code and document previews, recording services, dictation, Review Mode, push notifications, and Google Play Billing. ## Handbook: Bundled tools - [Chrome Browser Bridge](https://www.hbcode.ai/docs/tools/browser-bridge.md): Learn how the Chrome extension and native host let agents search, read, click, type, upload files, and capture screenshots. - [Agent tools: documents, speech, messages](https://www.hbcode.ai/docs/tools/agent-tools.md): Explore native HTML authoring and the agent tools for speech, video analysis, phone alerts, session lookup, and messages between sessions, for both agents. - [Dictation and vocabulary](https://www.hbcode.ai/docs/tools/dictation.md): Set up desktop dictation with OpenAI or Gemini, add project vocabulary, and trace transcription errors across desktop and mobile. ## Handbook: Contribute - [Build, test, and contribute](https://www.hbcode.ai/docs/contributing.md): Build HB Code from source, make a focused change, and run the checks for desktop, server, mobile apps, and shared contracts. - [Server operations](https://www.hbcode.ai/docs/server-operations.md): Understand the account and relay server, PostgreSQL roles, development configuration, and checks for deployment and service health. - [Troubleshooting](https://www.hbcode.ai/docs/troubleshooting.md): Diagnose HB Code sign-in, connection, delivery, tool, and session message issues for Codex and Claude. Find the failing layer before you retry. - [Engineering changelog](https://www.hbcode.ai/docs/changelog.md): Follow selected HB Code desktop, server, iOS, and Android changes, grouped by the behavior they affect and linked to source evidence. ## Optional - [Home page](https://www.hbcode.ai/index.md): What HB Code is, the platforms, and where to get it. German edition: https://www.hbcode.ai/de/index.md. The HTML home page is also in French (/fr), Spanish (/es), Japanese (/ja), and Korean (/ko). - [Support](https://www.hbcode.ai/support): Email support for installing, signing in, billing, pairing a phone, and workspace access. - [Delete account](https://www.hbcode.ai/account-deletion): How to delete an HB Code account and what gets removed. - [Legal documents](https://www.hbcode.ai/legal): Terms, privacy policy, subprocessors, and imprint for the EU/UK and the United States. - [helpful bits GmbH](https://helpfulbits.com): The company that makes HB Code.