bbvsT3 Code

The T3 Code alternative where your agents work together

Claude Code builds, Codex reviews in its own thread, and you can message either one mid-run. Free and open source, on Mac, Windows, and Linux.

Download for macOSApple Silicon · Also for LinuxWindows, Intel Macs & remote machines

Change anything, no fork needed

Browse the plugin marketplace or ask an agent to build the panel, command, or agent you want. It’s ready right away, wherever you use bb, including your phone.

Build a Linear plugin
Bring my Linear issues to bb
I'll build it as a bb plugin and mount it in your sidebar.
wrote plugin: linear
registered panel + bb linear CLI
Done. Linear is live, and your agents can use it.
Bring my Linear issues to bb
OpenAICodex
bb/linear-plugin

Hand off the whole job

Give one agent a big task. It splits the work across Claude Code, Codex, Cursor, and others running side by side, and they message each other as they go. You come back to finished work, not notes to pass between tools.

Works with any agent+5 more

Need another? Add it with a plugin.

bbvsT3 Code

Feature by feature

AgentsbbT3 Code
Agents
Message a subagentYesMid-run, from any deviceNoSubagent threads can't take messages
Switch accounts at usage limitsYesSwitches accounts automaticallyPartlyTracks limits, you switch
Multi-agent supportYesClaude Code, Codex, Pi, and any ACP agentYesClaude Code, Codex, Cursor, OpenCode, and more
Customize
Plugin marketplaceYesGallery or agent-builtNoFork the code
Everything you use today
Git worktree per threadYesSetup and teardown scriptsYes
Review and mergeYesLine comments, checks, mergeYes
Phone and remote accessYesiOS, Android, any browserYes
Go back to an earlier pointYesEdit a message or fork from itYes
Price and license
Pricing$0Any team size$0No paid plan
Open-source licenseYesMITYesMIT

FAQ

Switching from T3 Code

What’s the difference between bb and T3 Code?

Both are free, MIT-licensed apps that run Claude Code, Codex, and other coding agents in Git worktrees on your own machines, with mobile and remote access. In bb, every agent another agent starts is a full thread you can open and message mid-run. You change bb with plugins instead of a fork, and Account Pooler moves a thread to your next account when one hits its limit.

Is there a free, open-source T3 Code alternative?

Yes: bb. It’s free for any team size and MIT-licensed, so you can use and change it for anything, including at work. Your agents work together across providers, and plugins add whatever you need without forking. Download bb.

How do I move my projects and worktrees to bb?

Ask bb to do it. T3 Code keeps each thread’s worktree as plain Git on your machine, in ~/.t3/worktrees, so a bb agent can add your repos and open each unfinished worktree as a thread. Your CLAUDE.md, skills, MCP servers, and agent sign-ins come along, and T3 Code keeps working while you try bb.

What’s different day to day?
  • When an agent starts another, the new one is a full thread you can message.
  • Several threads can share one worktree, so a reviewer works right next to the agent that wrote the code.
  • Setup commands from t3.json move to .bb-env-setup.sh, and untracked files like .env go in .worktreeinclude.
  • When you want a new panel, command, or agent, you install or build a plugin instead of patching the app.
How do I get started?
  1. Download bb for macOS (Apple Silicon), Windows, or Linux (alpha). On an Intel Mac, run npx bb-app@latest, which needs Node.js 22.19 or later.
  2. Install and sign in to a coding agent, like Claude Code, Codex, Cursor, or OpenCode.
  3. Open bb, add your project folder, and type your first request.

Agents

Which coding agents does bb support?

Claude Code, Codex, Cursor, and OpenCode, plus Pi, Grok Build, omp, and Hermes Agent. In Settings, add any other agent that supports the Agent Client Protocol (ACP), an open standard for connecting coding agents to apps, like Gemini CLI or Devin. You can also add one with a plugin. Each thread can use a different agent.

Can I use Claude Code and Codex together?

Yes. Ask Claude Code to “start a bb Codex thread to review this branch, then fix what it finds.” It starts Codex in the same worktree, waits, and applies the fixes. Codex shows up as its own thread, so you can read the exact prompt Claude sent, watch it work, and message it mid-run. Any other pair works the same way, like Cursor and OpenCode.

Can bb switch accounts when I hit a usage limit?

Yes, with Account Pooler, an experimental plugin built into bb. Turn it on and add the Claude Code and Codex accounts you own. When one account hits its limit, bb moves the thread’s requests to the next one, so it keeps running. T3 Code shows your accounts’ limits, but you switch accounts yourself.

Can I control what my agents are allowed to do?

Yes. Pick a permission mode for each thread. Accept Edits applies changes inside the project and asks before anything else. Approve for me reviews requests automatically and sends high-risk ones to you. Full Access skips approvals and can run anything on your machine. Allow or deny approvals from your computer or your phone.

Your T3 Code workflow in bb

Does bb have setup scripts for new worktrees?

Yes. Commit a .bb-env-setup.sh at your repo root and bb runs it in every new worktree. List untracked files like .env in .worktreeinclude and bb copies them in first, and .bb-env-teardown.sh cleans up when a worktree goes away.

Can I review and merge an agent’s changes in bb?

Yes, without leaving the thread. Select lines in its diff and choose Add to chat to send feedback. Once the agent opens a pull request, the thread shows its checks and a Merge button. The GitHub plugin adds Review with agent to any PR.

Does bb have checkpoints?

bb lets you rewind the conversation instead. Edit any earlier message to rerun the thread from there, or fork a new thread from any message to try a different approach. In a worktree thread, changes stay on that thread’s branch until you merge them.

Can I control my coding agents from my phone?

Yes, for free. Use the bb mobile app, a public beta on iPhone through TestFlight (Apple’s beta testing app) and in alpha on Android, or open bb in any browser through bb Connect, bb’s free remote access.

Can bb run agents on a schedule?

Yes, free. Automations start an agent thread or run a script on a repeating schedule, once at a set time, or after a delay. Pick the agent, model, and permission mode, and give each run its own worktree if you like.

Can I customize bb with plugins or scripts?

Yes. bb works out of the box, with worktrees, diff review, automations, and the mobile app ready from your first thread. When you want more, install plugins from the marketplace or ask an agent to build one. Plugins can add panels, commands, and new agents, and they work in the mobile app too. Everything in the app is also in the bb CLI and HTTP API, so scripts and other agents can start, message, and manage threads.

Price, platforms, and privacy

Is bb free and open source?

Yes, for one person or a whole team. The mobile app, remote machines, automations, and plugins are all included. You pay only for the agent plans or API keys you already use, from any provider. The code is on GitHub under the MIT license.

Can I use my existing AI subscriptions with bb?

Yes. bb runs the agents you already use, signed in the way you already pay for them: a Claude Pro or Max plan, a ChatGPT plan for Codex, a Cursor plan, API keys, or any other provider’s plan. Your existing setup comes along too (CLAUDE.md, skills, MCP servers, and agent settings).

Does bb run on Mac, Windows, and Linux?

Yes. Download the app for Apple Silicon Macs, Windows, or Linux (alpha), or run npx bb-app@latest on an Intel Mac.

Is my code private with bb?

Yes: bb runs on your machines, so your code goes only where your agents send it, the AI providers you chose. Anonymous usage stats exclude code and prompts and can be turned off. The bb Connect relay doesn’t store traffic, but isn’t end-to-end encrypted.

Can my team use bb?

Yes, free at any team size. Each person runs bb on their own machines with their own agent subscriptions and shares work through Git and pull requests as usual. bb doesn’t offer team plans, SSO, or a support SLA.

Get your agents working together

Free and open source. Bring the AI plans you already pay for.

Download for macOSApple Silicon · Also for LinuxWindows, Intel Macs & remote machines

Built by alumni from

  • Figma
  • Meta
  • Quora
  • Mapbox