/plan-feature

Plan a feature before implementation (Two-Phase Pattern - Phase 1):

Arguments: $ARGUMENTS

Core Principle

Separate planning from implementation for better outcomes. This is Phase 1: Planning. Phase 2 is /implement.

Phase 1: Load Context

1. Parse feature ID from arguments
2. Read feature from .claude-harness/features/active.json (or .claude-harness/feature-list.json for v2.x compat)
3. Read compiled context from .claude-harness/memory/working/context.json
4. Read semantic memory for project architecture

Phase 2: Analyze Requirements

5. Break down feature into sub-tasks
6. Identify files to create/modify
7. Identify dependencies on other features/modules

Phase 3: Impact Analysis

8. Read .claude-harness/impact/dependency-graph.json
9. For each file to modify:
   • Identify dependent files (importedBy)
   • Identify related tests
   • Calculate impact score
10. Warn if high-impact changes detected

Phase 4: Check Past Approaches

11. Read .claude-harness/memory/procedural/failures.json
12. Check if planned approach matches any past failures
13. If match found:
    • Warn about similar past failure
    • Show root cause and prevention tips
    • Suggest alternative approach from successes.json

Phase 5: Generate Tests (if not done)

14. If feature.tests.generated = false:
    • Automatically run test generation
    • Or prompt to run /generate-tests first

Phase 6: Create Implementation Plan

15. Write implementation plan to feature:

    {
      "plan": {
        "steps": [
          {"step": 1, "description": "...", "files": [...]},
          ...
        ],
        "estimatedFiles": ["file1.ts", "file2.ts"],
        "impactScore": "low|medium|high",
        "risks": ["..."],
        "mitigations": ["..."]
      }
    }
    

Phase 7: Update Feature

16. Update feature in active.json:
    • Set phase to "planned"
    • Store implementation plan

Phase 8: Report

17. Report:
    • Implementation steps
    • Files to modify
    • Impact analysis
    • Risks and mitigations
    • Past failures to avoid
    • Next: Run /claude-harness:implement feature-XXX to start coding