Plan mode

Plan mode keeps the coding agent to reading and planning: it may explore the code but change nothing until a person approves the plan. It is a mode of the agent itself.

Finding it

• Claude Code: Shift+Tab switches into it, claude --permission-mode plan starts in it, and defaultMode in the settings' permissions makes it the default.
• Other coding agents: a plan mode of their own, or a read-only approval setting.

Using it

• For work whose direction a person should settle first: a change across many files, a migration, anything hard to undo.
• The plan names the files to change, the steps, and how each step will be checked.
• Keep the approved plan, in the repository or the session's record, so later work can be checked against it.
• A rejected plan comes back with the reason, and the agent plans again.

Examples: plan mode in Claude Code and in Codex.