Introduction

spwn is a native macOS app for running Claude Code agents in parallel. Every Claude session works on its own git branch, in its own isolated copy of your code — so you can explore several approaches at once and merge back only what worked.

The problem

A Claude Code conversation is a straight line in a single terminal. Real work isn’t:

• You want to try an idea one way, back out, and try it another — without losing the first attempt.
• You want a few agents working at once, not one at a time.
• You lose running work the moment a terminal window closes.
• You re-explain the same project background to every fresh session.

You can stitch this together yourself with git worktrees, terminal multiplexers, and a notes file. spwn is what that would become if you built it properly — and then didn’t have to maintain it.

The idea

spwn adds a thin layer over your existing Claude Code setup that makes parallel, disposable exploration the default:

1. A branch and workspace per session. Each Claude session runs on its own spwn/… git branch in its own worktree, copy-on-write seeded with your build folders so it’s ready to build immediately. Sessions run side by side without clashing.
2. Merge back only the winners. Every session commits as it goes, so its branch is always real, mergeable history. Merge with a click or with plain git — nothing lands on its own.
3. Explore without losing work. Fork a session to branch off, or use the Timeline to return to an earlier point. Sessions keep running after you quit the app.
4. Start primed, not cold. Collect the notes, files, and best answers for a project in its Merge tray, then Inject them as the first message of a new session.
5. Runs that happen on their own. Schedule read-only tasks against a project and read the results when you’re back.

Core concepts

Three terms cover most of spwn; the rest are defined in the Glossary.

• Project — a name and a folder that groups everything you do there: its sessions, shells, Merge tray, and scheduled tasks. You decide what’s a project and what it’s called.
• Session — an isolated Claude workspace: its own conversation and its own copy of your code, on its own git branch. This is the unit you explore, fork, and merge.
• Shell — a plain terminal in the project folder. No conversation, no branch — just a shell for git, builds, and tests.

Next

• Installation — get spwn running on your Mac.
• Quick Start — create a project and run your first parallel sessions.