Implementation Plan Workflow

Create an implementation plan for a specific feature.

Input

Feature ID: $ARGUMENTS (e.g., "CORE-001")

Context

Skills to load:

katachi:framework-core - Workflow principles
katachi:working-on-feature - Per-feature workflow

Feature inventory: @planning/FEATURES.md - Feature definitions @planning/DEPENDENCIES.md - Feature dependencies

Feature documents: @specs/$ARGUMENTS.md - What to build (requirements) @designs/$ARGUMENTS.md - Why/how (design rationale)

Project decisions: @docs/architecture/README.md - Architecture decisions (ADRs) @docs/design/README.md - Design patterns (DES)

Existing plan (if present): @plans/$ARGUMENTS.md - Current plan to update or create

Pre-Check

Verify spec and design exist:

If specs/$ARGUMENTS.md doesn't exist, suggest /katachi:spec-feature $ARGUMENTS first
If designs/$ARGUMENTS.md doesn't exist, suggest /katachi:design-feature $ARGUMENTS first
Plan requires both spec and design

Process

0. Check Existing State

If plans/$ARGUMENTS.md exists:

Read current plan
Check for drift: Have spec or design changed?
Summarize: steps, pre-implementation items, files to change
Ask: "What aspects need refinement? Or should we review the whole plan?"
Enter iteration mode as appropriate

If no plan exists: proceed with initial creation

Update status:

python ${CLAUDE_PLUGIN_ROOT}/scripts/features.py status set $ARGUMENTS "⧗ Plan"

1. Research Phase (Silent)

Read feature spec (specs/$ARGUMENTS.md)
Read feature design (designs/$ARGUMENTS.md)
Read relevant ADRs and DES patterns (not just indexes)
Read dependency code as needed
Explore codebase for implementation patterns
Build complete understanding without asking questions

2. Draft Complete Plan Proposal

Create full implementation plan following template:

Pre-Implementation Checklist:

Spec read
Design read
Dependency code to read (specific files)
Relevant ADRs (specific documents)
Relevant DES patterns (specific documents)

Implementation Steps: For each step:

Create/modify: specific file paths
What to do: specific instructions
Test: how to verify this step

Ensure:

Every acceptance criterion has implementing steps
Steps are in dependency order
Steps are atomic and verifiable

Files Changed:

List all files to be modified
Include test files

3. Present Proposal for Review

Show complete plan document to user. Highlight any uncertainties. Invite feedback: "What needs adjustment in this plan?"

4. Iterate Based on Feedback

Apply user corrections, additions, or changes. Re-present updated sections if significant changes. Repeat until user approves the plan.

5. External Validation

Dispatch the plan-reviewer agent:

Task(
    subagent_type="katachi:plan-reviewer",
    prompt=f"""
Review this implementation plan.

## Feature Spec
{spec_content}

## Feature Design
{design_content}

## Implementation Plan
{plan_content}

## Relevant ADR/DES Summaries
{adr_des_summaries}

Provide structured critique covering:
- Acceptance criteria coverage (map each to steps)
- Pre-implementation checklist completeness
- Step granularity
- Verification points
- Dependency order
- File changes completeness
"""
)

Review agent findings with user. Discuss which recommendations to accept.

6. Finalize with Iteration Check

Ask: "Should we iterate based on validation feedback, or is the plan complete?"

If gaps to address → refine relevant sections (go back to step 4) If complete → finalize document to plans/$ARGUMENTS.md