Add reasoning effort toggle and slash commands for Claude Code (ACP) in Agent Panel

[AlexanderVoid45]

When using Claude Code as an external agent via ACP, there is no way to switch reasoning effort level from the Agent Panel UI.

Additionally, slash commands that are available in Claude Code CLI (like /effort /compact, etc.) are completely inaccessible when running inside Zed's Agent Panel. The chat input doesn't pass them through to the agent.

There is also no context window usage indicator - it's impossible to tell how much of the context is consumed during a conversation.

Proposed solution

1. Add a reasoning effort dropdown (similar to what was implemented for Codex CLI in Codex CLI missing dropdowns for reasoning effort and/or approvals #48132) to the Agent Panel toolbar when Claude Code (ACP) is selected as the provider.
2. Show a context window usage bar/indicator so the user knows when to compact or start a new conversation.

Use case

Different tasks benefit from different effort levels - quick questions don't need max reasoning, while complex multi-file refactors do. Being able to toggle this without leaving the editor would save time and tokens.

Current workaround

None within Zed UI. The only option is to use Claude Code in a separate terminal where these features are available.

[alexshtf]

Oh, that would be great!

[laraibg786]

This should be done in a formal feature request issue IMHO to get more traction and some response from the maintainers.

[alexshtf]

Referenced in this issue:
#53583

[58facettes]

Same for running open ai models with your own key. I just can't select the reasoning effort.

[christophebeling]

The feature request was just closed. How comes? Can't be a lot of effort to implement.

[anicioalexandre]

since there is no UI to indicate the effort, you can probably control it via .claude/settings.local.json

{
  "env": {
    ...
    "CLAUDE_CODE_EFFORT_LEVEL": "max"
  }
}

[AlexanderVoid45]

I am working in several windows on the same project (via nested subfolders), so a global setting is not an option for me. I want to switch effort on the fly for each task, because some tasks need to be performed with low effort while still using the top model

[langtutheky]

The newest update Zed 0.233.10 added Effort Selection. This feature is already implemented.

Zed 0.233.10
Commit: 350f338
Version: 0.233.10+stable.250.350f33871e84d5ed83a403523e9490b9bf014a94

[AlexanderVoid45]

Thank you for implementing the reasoning effort selector. I'd like to report an issue with the Favorites functionality: although I have marked "Max" as a favorite, each new chat is initialized with "Low" effort instead. The favorite is displayed correctly under the Favorites section of the dropdown, but it does not affect the default selection for new conversations. The expected behavior would be for the favorited option to be applied as the default effort level when starting a new chat.

[langtutheky]

Please open this as a new issue for bug.