Skip to content

plan-mode.md

Latest commit

 

History

History
245 lines (191 loc) · 8.66 KB

plan-mode.md

File metadata and controls

245 lines (191 loc) · 8.66 KB

Plan Mode (experimental)

Plan Mode is a read-only environment for architecting robust solutions before implementation. It allows you to:

  • Research: Explore the project in a read-only state to prevent accidental changes.
  • Design: Understand problems, evaluate trade-offs, and choose a solution.
  • Plan: Align on an execution strategy before any code is modified.

Note: This is a preview feature currently under active development. Your feedback is invaluable as we refine this feature. If you have ideas, suggestions, or encounter issues:

  • Open an issue on GitHub.
  • Use the /bug command within Gemini CLI to file an issue.

Enabling Plan Mode

To use Plan Mode, enable it via /settings (search for Plan) or add the following to your settings.json:

{
  "experimental": {
    "plan": true
  }
}

How to use Plan Mode

Entering Plan Mode

You can configure Gemini CLI to start in Plan Mode by default or enter it manually during a session.

  • Configuration: Configure Gemini CLI to start directly in Plan Mode by default:

    1. Type /settings in the CLI.
    2. Search for Default Approval Mode.
    3. Set the value to Plan.

    Alternatively, use the gemini --approval-mode=plan CLI flag or manually update:

    {
  "general": {
    "defaultApprovalMode": "plan"
  }
}

  • Keyboard Shortcut: Press Shift+Tab to cycle through approval modes (Default -> Auto-Edit -> Plan).

    Note: Plan Mode is automatically removed from the rotation when Gemini CLI is actively processing or showing confirmation dialogs.

  • Command: Type /plan in the input box.

  • Natural Language: Ask Gemini CLI to "start a plan for...". Gemini CLI then calls the enter_plan_mode tool to switch modes.

    Note: This tool is not available when Gemini CLI is in YOLO mode.

Planning Workflow

  1. Explore & Analyze: Analyze requirements and use read-only tools to map the codebase and validate assumptions. For complex tasks, identify at least two viable implementation approaches.
  2. Consult: Present a summary of the identified approaches via ask_user to obtain a selection. For simple or canonical tasks, this step may be skipped.
  3. Draft: Once an approach is selected, write a detailed implementation plan to the plans directory.
  4. Review & Approval: Use the exit_plan_mode tool to present the plan and formally request approval.
    • Approve: Exit Plan Mode and start implementation.
    • Iterate: Provide feedback to refine the plan.

For more complex or specialized planning tasks, you can customize the planning workflow with skills.

Exiting Plan Mode

To exit Plan Mode, you can:

  • Keyboard Shortcut: Press Shift+Tab to cycle to the desired mode.

  • Tool: Gemini CLI calls the exit_plan_mode tool to present the finalized plan for your approval.

Tool Restrictions

Plan Mode enforces strict safety policies to prevent accidental changes.

These are the only allowed tools:

Customizing Planning with Skills

You can use Agent Skills to customize how Gemini CLI approaches planning for specific types of tasks. When a skill is activated during Plan Mode, its specialized instructions and procedural workflows will guide the research, design and planning phases.

For example:

  • A "Database Migration" skill could ensure the plan includes data safety checks and rollback strategies.
  • A "Security Audit" skill could prompt Gemini CLI to look for specific vulnerabilities during codebase exploration.
  • A "Frontend Design" skill could guide Gemini CLI to use specific UI components and accessibility standards in its proposal.

To use a skill in Plan Mode, you can explicitly ask Gemini CLI to "use the <skill-name> skill to plan..." or Gemini CLI may autonomously activate it based on the task description.

Customizing Policies

Plan Mode is designed to be read-only by default to ensure safety during the research phase. However, you may occasionally need to allow specific tools to assist in your planning.

Because user policies (Tier 2) have a higher base priority than built-in policies (Tier 1), you can override Plan Mode's default restrictions by creating a rule in your ~/.gemini/policies/ directory.

Example: Allow git commands in Plan Mode

This rule allows you to check the repository status and see changes while in Plan Mode.

~/.gemini/policies/git-research.toml

[[rule]]
toolName = "run_shell_command"
commandPrefix = ["git status", "git diff"]
decision = "allow"
priority = 100
modes = ["plan"]

Example: Enable research subagents in Plan Mode

You can enable experimental research subagents like codebase_investigator to help gather architecture details during the planning phase.

~/.gemini/policies/research-subagents.toml

[[rule]]
toolName = "codebase_investigator"
decision = "allow"
priority = 100
modes = ["plan"]

Tell Gemini CLI it can use these tools in your prompt, for example: "You can check ongoing changes in git."

For more information on how the policy engine works, see the policy engine docs.

Custom Plan Directory and Policies

By default, planning artifacts are stored in a managed temporary directory outside your project: ~/.gemini/tmp/<project>/<session-id>/plans/.

You can configure a custom directory for plans in your settings.json. For example, to store plans in a .gemini/plans directory within your project:

{
  "general": {
    "plan": {
      "directory": ".gemini/plans"
    }
  }
}

To maintain the safety of Plan Mode, user-configured paths for the plans directory are restricted to the project root. This ensures that custom planning locations defined within a project's workspace cannot be used to escape and overwrite sensitive files elsewhere. Any user-configured directory must reside within the project boundary.

Using a custom directory requires updating your policy engine configurations to allow write_file and replace in that specific location. For example, to allow writing to the .gemini/plans directory within your project, create a policy file at ~/.gemini/policies/plan-custom-directory.toml:

[[rule]]
toolName = ["write_file", "replace"]
decision = "allow"
priority = 100
modes = ["plan"]
# Adjust the pattern to match your custom directory.
# This example matches any .md file in a .gemini/plans directory within the project.
argsPattern = "\"file_path\":\"[^\"]*/\\.gemini/plans/[a-zA-Z0-9_-]+\\.md\""