Magnitude is an open source coding agent built from the ground up around subagents. You chat with the lead agent and it coordinates specialized subagents — explorers, planners, builders, reviewers, debuggers, and a browser agent — on your behalf.
- Building happens in subagents, so the lead stays focused on you
- Subagents are long-lived and resumable, not disposable
- The lead can redirect subagents mid-task without starting over
- Subagents are spun up in parallel for faster work
- A shared workspace keeps handoffs between agents lossless
- Mix and match models by role to balance intelligence and speed
npm install -g @magnitudedev/cliThen navigate to the directory you want to work in and launch the TUI:
magnitudeThis will launch Magnitude with a setup wizard for configuring providers and models.
Magnitude works with most major model providers out of the box, including open source and local models.
You can use your ChatGPT Plus/Pro or GitHub Copilot subscription.
See the provider docs for full provider support.
The lead agent manages all subagents on your behalf. It can message, stop, resume, or redirect them and run many in parallel. You can also message subagents directly.
Magnitude comes out of the box with the following subagents:
- Explorer: for doing codebase or web research, both broad and narrow
- Planner: for evaluating various implementation strategies
- Builder: for implementing code changes directly in your files
- Reviewer: for strict, independent review of code changes
- Debugger: for root causing bugs and fixing them
- Browser: for verifying UI changes with a built-in browser agent
Magnitude may use none or all of these in a given session. For a quick fix in a single file, it may edit it directly. For a very in-depth change, it may use the whole team. For most tasks, it will use some combination of explorer, planner, builder, and reviewer.
We became fully subagent-pilled the first time we saw Claude Code use an explore agent. We expected it to continue getting better and better. But it didn't.
The community clearly feels the same — projects like Superpowers have hit 100k+ GitHub stars augmenting Claude Code with more subagents. But they're plugging into an existing primitive that wasn't designed for deep subagent orchestration.
Instead of plugging into an existing primitive, we built a new one from the ground up. That's the difference between bolting on subagents and building around them.
Full documentation is available at docs.magnitude.dev.
See the contributing guide to get started.
Built on top of BAML, Effect, and OpenTUI.
Inspired by other open-source coding agents, including OpenCode and Codex.