feat: per-session Claude Code argument customization

[wonderchook]

Feature Request

Currently, Claude Code extra arguments (e.g. --permission-mode auto) are configured globally in Settings > General and apply to every new session. This works well as a default, but sometimes you want different flags for different sessions — for example, using --permission-mode auto in one tab while keeping the default in another.

Proposed Behavior

Add a "Customize arguments per session" checkbox in Settings > General. When enabled:

1. Creating a new Claude tab shows a dialog pre-filled with the global extra arguments
2. The user can edit the arguments for that specific session before launching
3. Clicking "Start" launches the session with the customized arguments
4. Clicking "Cancel" aborts tab creation
5. The global "Extra arguments" setting still serves as the default pre-fill

When the checkbox is disabled, behavior is unchanged — new Claude tabs use the global args silently.

Why

• Different projects may need different permission modes
• Testing with specific flags shouldn't require changing the global setting and remembering to change it back
• Power users want fine-grained control without friction for the common case

Screenshots

Settings pane with the new checkbox:

Dialog shown when creating a new Claude tab:

Note: Screenshots are from a working implementation on the feat/per-session-claude-args branch.

[gi11es]

Would it be useful to you to also be able to set a default set of parameters per project/folder?

global defaults > project defaults > custom

The project defaults could be definable either through a contextual right-click menu on the project, or as a tickbox when entering a custom one in your new dialog box.

As for defining the parameters on-the-fly for the custom case you're introducing, since there's only a finite set of start parameters, would it be useful to have auto-complete? I figure a smart contextual auto-complete of Claude Code start parameters could be useful in all those different contexts where we might enter them.

[wonderchook]

I think default parameters by project would be useful. And then having an easy way to override them. Because the main use case I have is needing different parameters per project, primarily depending on how much I trust it, but sometimes there's other reasons.

Autocomplete would definitely save me time instead of going to look up exact spelling.