CLI: Auto-switch provider/model when LLM delegates to different modes

[benzntech]

What This Does

When Claude uses the switchMode or newTask tools to automatically delegate work to a different mode, the CLI now automatically switches to that mode's preferred AI provider and model.

Previously, only manual /mode commands would switch the provider/model. Now automatic mode switching works the same way.

Why This Matters

If you configure modes with specific providers/models (e.g., use GPT-4 for planning, Claude for coding), the CLI will now respect those preferences even when the LLM switches modes automatically during a task.

Before: LLM switches to "planning" mode → CLI stays on current provider
After: LLM switches to "planning" mode → CLI switches to planning mode's preferred provider/model

Changes Made

File: cli/src/state/hooks/useApprovalMonitor.ts

Added a new effect that:

• Watches for switchMode and newTask tool approvals (both auto and manual)
• Looks up the target mode's preferredProviderId and preferredModelId
• Switches the CLI's active provider/model to match
• Handles errors gracefully without blocking tool execution

How to Use

1. Configure modes with preferred providers in custom_modes.yaml:

modes:
  - name: "Code Review"
    slug: "code-review"
    preferredProviderId: "anthropic-1"
    preferredModelId: "claude-opus-4"
  - name: "Quick Tasks"
    slug: "quick-tasks"
    preferredProviderId: "openai-1"
    preferredModelId: "gpt-4o-mini"

2. Start a task in any mode
3. When the LLM delegates to another mode, the provider/model switches automatically
4. Verify with /provider command

Testing

• ✅ Build successful
• ✅ All 2076 tests passing
• ✅ Type checking passed
• ✅ Linting passed

Technical Details

The implementation uses a separate useEffect hook that monitors lastAskMessage for answered tool calls. This approach:

• Covers both auto-approval and manual approval paths
• Avoids duplicating logic across multiple code paths
• Uses de-duplication to prevent multiple switches for the same tool call
• Includes memory leak prevention (cleans up old timestamps)

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Latest commit: bde4e22

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