3.4 — Plan Mode vs Direct Execution

CCAR-F Domain 3 · Task 3.4

What You Need to Know

Claude Code has two main modes:

• Plan mode: reads the codebase, analyses dependencies, proposes an approach — does not modify files until you approve.
• Direct execution: makes changes straight away.

When to Use Plan Mode

• Large-scale changes / restructuring
• Multiple valid approaches exist
• Architectural decisions required
• Multi-file modifications
• Codebase exploration needed

How to enter: claude --permission-mode plan, Shift+Tab, or prefix with /plan.

When to Use Direct Execution

• Well-scoped change (single-file bug with clear stack trace)
• Correct approach already known
• Limited scope (one function, one file)

Key Concept: The decision is about ambiguity, not difficulty. A difficult but well-defined bug fix is direct execution. A seemingly simple feature with multiple approaches is plan mode.

The Explore Subagent

Keeps verbose discovery output out of the main conversation. Runs exploration in isolation and returns summaries.

Hybrid Approach: Plan Then Execute

1. Plan phase → explore, evaluate, design strategy
2. Execute phase → implement the planned approach file by file

Decision Framework

Task	Mode
Architectural restructuring	Plan
Library migration (many files)	Plan then execute
Multiple valid approaches	Plan
Single-file bug with clear stack trace	Direct
Known fix, known location	Direct

Exam Traps

• Defaulting to direct execution for multi-file architectural changes
• Using plan mode for a single-file bug with clear stack trace
• Doing verbose discovery in the main conversation
• Starting direct and switching to plan only when complexity emerges