How it works & your data

spwn is a native macOS app that sits on top of your existing Claude Code setup. This page explains what it touches and where your data lives — the short version is: it uses your Claude and your files, and keeps its own data on your Mac.

It uses your own agent

spwn runs your authenticated claude command with your existing login. There is no separate account, no sign-in inside spwn, and nothing is proxied through a server in between. Your conversations go straight to Claude the same way they do when you run claude yourself.

In fact spwn runs the agent’s own terminal UI, in a pane — so what you’re talking to is exactly the CLI you’d get in a terminal, with its own prompts and shortcuts. That also means spwn isn’t limited to Claude: any agent CLI can be described in a small config file and driven the same way. See Agents.

If your claude is installed somewhere unusual, point spwn at it in Settings.

It reads your real Claude history

Claude Code already stores your sessions on your machine. spwn reads that history directly to show your conversations and keep them in sync — it’s a view of the same sessions you’d see in the terminal, not a separate copy kept somewhere else.

Sessions keep running

Your shell and agent sessions run in the background and are managed so they survive closing the app. That’s why reopening spwn brings everything back exactly where you left it, including running programs. Fork and the Timeline build on this: a fork is a real branched session, and the Timeline rolls a session back to an earlier checkpoint.

Sessions work on their own branch

In a git project, each Claude session works on its own branch in your real repo (named spwn/…), with its own checkout kept in the app’s data folder. This is what lets sessions run in parallel without clashing, and it keeps their work off to the side until you merge it back. Your project folder stays on whatever branch you had checked out; spwn only ever adds spwn/… branches and never moves your branch or rewrites your history. Non-git projects run in the project folder directly, with no branches. See Branches & Merging.

Your data stays local

• Projects, Merge trays, and scheduled tasks you create in spwn are stored locally on your Mac, in the app’s own data folder. They’re yours; spwn doesn’t upload them anywhere.
• Scheduled tasks run read-only — they can read your project and its Merge tray but never modify your files.
• spwn talks to exactly two things: your local Claude and your local files. Nothing else leaves your machine.

Building it yourself

spwn is open source. If you want to build it from source or contribute, see Building from Source.