Installation¶
Install the package¶
Run the setup wizard¶
The wizard walks you through:
- API key — Enter your Zwischen API key (from zwischen.ai). This is stored in
~/.zwischen/settings.yaml. - Model selection — Choose which AI model the reviewer should use. See supported models.
- Provider API key — Enter the API key for the model's provider (OpenAI, Anthropic, Google, or DeepSeek).
- Claude Code wiring — The wizard installs hooks into your Claude Code settings, registers the MCP server, and installs the
/zslash command skill.
When the wizard finishes, Zwischen is ready. Start (or restart) Claude Code and the reviewer will attach automatically.
Install options¶
| Command | What it does |
|---|---|
zwischen install |
Full interactive wizard |
zwischen install --dry-run |
Preview all changes without writing anything |
zwischen install --print |
Print the hook and MCP config for manual application |
zwischen install --update |
Re-wire hooks, MCP, and skills without running the wizard (use after updating) |
What gets installed¶
The installer modifies two Claude Code config locations:
~/.claude/settings.json — Adds hook entries for all eight Claude Code hook events (SessionStart, SubagentStart, SubagentStop, PreToolUse, PostToolUse, PostToolUseFailure, UserPromptSubmit, Stop) and registers the Zwischen MCP server.
~/.claude/skills/z/ — Installs the /z slash command skill that provides in-session interaction with the reviewer.
~/.zwischen/settings.yaml — Created if it doesn't exist. Stores your API key, model selection, and all reviewer configuration. You can edit this file directly at any time — settings are re-read on every session start.
No background processes
The install wizard does not start any background services. The Zwischen daemon starts automatically when you launch a Claude Code session and stops when the session ends.
Verifying the installation¶
After installing, start Claude Code. You should see a message at the beginning of your session indicating that Frank (the reviewer) has attached. You can also run:
If this returns a session ID, Zwischen is active. See First Session for a walkthrough.