What it does
/config opens an interactive settings panel where you can adjust Claude Code's core behavior: visual theme, default Claude model, when the conversation auto-compacts, and whether to show the status line. Changes take effect immediately or on the next conversation turn, and your selections are saved to .claude/settings.json in your project.
When to use it
Use /config when you want to tune Claude Code without editing JSON by hand. This includes:
- Switching between light and dark theme (persists across sessions)
- Changing your default model — swap from Haiku to Sonnet if you need more reasoning depth on this project
- Adjusting autoCompactThreshold — if context is compressing too aggressively (default 25,000 tokens), raise it; if memory is tight, lower it
- Toggling the statusLine — the line at the bottom showing your current context position. Useful to disable on small screens
These are project-local settings, so your theme preference can differ between repos. Global preferences (like your default model across all projects) live in ~/.claude/config.json and can be tweaked the same way.
Try it yourself
Type /config in your current session and browse the available toggles. Change one — say, switch to dark mode or bump the model up to Sonnet — and notice the change applies right away. Your project's .claude/settings.json file will reflect it, so teammates on the same repo see the same base config if they check it in.
Gotchas
Settings hierarchy: Project settings (.claude/settings.json) override global settings (~/.claude/config.json). If you set a model in /config while in a project, it only affects that project. To change your global default, use /config outside any repo.
JSON editing fallback: If you prefer hand-editing or need to set something /config doesn't expose, you can edit .claude/settings.json directly with your editor. The format is straightforward, but be careful with commas and brackets — invalid JSON will be ignored on next load, reverting to defaults.
Model + effort: Changing the model via /config is quick, but if you need to also adjust reasoning effort (low, high, max), that's a separate /config toggle on newer versions. Check what your version offers.
Cache effect: Some settings (like autoCompactThreshold) affect how your context is compressed on the next turn, not retroactively on the current one. If you're mid-conversation and feel the context is behaving oddly, changing the threshold won't fix the current window — it'll apply once you send another message.
Try it yourself
Type the command in the fake terminal. Nothing leaves your browser.