Starting an Implementation Plan

Overview

Orchestrate the transition from design document to executable implementation through planning and execution handoff.

Core principle: Branch -> Plan -> Execute. Isolate work, create detailed tasks, hand off to execution.

Announce at start: “I’m using the starting-an-implementation-plan skill to create the implementation plan from your design.”

REQUIRED: Design Plan Path

DO NOT GUESS. If the user has not provided a path to a design plan, you MUST ask for it.

Use AskUserQuestion:

Question: "Which design plan should I create an implementation plan for?"
Options:
  - [list any design plans you find in docs/design-plans/]
  - "Let me provide the path"

If docs/design-plans/ doesn’t exist or is empty, ask the user to provide the path directly.

Never assume, infer, or guess which design plan to use. The user must explicitly tell you.

The Process

This skill has three steps:

1. Branch Setup: Select and create branch for implementation
2. Planning: Create detailed implementation plan
3. Execution Handoff: Direct user to execute the plan

Step 0: Create orchestration task tracker

Use TaskCreate to track the orchestration steps:

TaskCreate: "Branch setup"
(conditional) TaskCreate: "Read project implementation guidance from [absolute path]"
  → TaskUpdate: addBlockedBy: [Branch setup]
  → (only if .ed3d/implementation-plan-guidance.md exists)
TaskCreate: "Create implementation plan"
  → TaskUpdate: addBlockedBy: [Branch setup] (or [Read guidance] if it exists)
TaskCreate: "Re-read starting-an-implementation-plan skill (restore context)"
  → (DO NOT set blockedBy yet - will be updated after granular tasks are created)
TaskCreate: "Execution handoff"
  → TaskUpdate: addBlockedBy: [Re-read skill]

CRITICAL: The “Re-read skill” task must be re-pointed AFTER writing-implementation-plans creates the Finalization task. See “After Planning: Update Dependencies” below.

The “Create implementation plan” task wraps the granular tasks created by writing-implementation-plans. The “Re-read skill” step ensures context is restored after potential compaction before handoff.

Branch Setup

Mark “Branch setup” task as in_progress.

Before planning, set up the branch and workspace for implementation work.

Extract the slug from the design plan filename (everything after YYYY-MM-DD-, excluding .md). For example, oauth2-svc-authn from 2025-01-18-oauth2-svc-authn.md.

This slug is used for:

1. Implementation plan directory name (docs/implementation-plans/YYYY-MM-DD-{slug}/)
2. Worktree directory name (.worktrees/{slug})
3. Scoping all AC identifiers — every acceptance criterion uses the format {slug}.AC{N}.{M}

The slug ensures AC identifiers are globally unique across multiple plan-and-execute rounds.

Step 1: Ask about worktree

REQUIRED: Use AskUserQuestion tool

Ask:

Question: "Do you want to use a git worktree for this implementation?"
Options:
  - "Yes - create worktree" (isolated workspace in .worktrees/[friendly-name])
  - "No - work in current directory" (standard branch workflow)

Step 2: Set up workspace based on choice

If user chooses “Yes – create worktree”:

1. REQUIRED SUB-SKILL: Use ed3d-plan-and-execute:using-git-worktrees
2. CONDITIONAL SKILLS: Activate any project-specific git worktree skills if they exist
3. Announce: “I’m using the using-git-worktrees skill to create an isolated workspace.”
4. Ask user which branch to use for the worktree:

   Question: "Which branch should I use for this worktree?"
   Options:
     - "[friendly-name]" (e.g., oauth2-svc-authn)
     - "$(whoami)/[friendly-name]" (e.g., ed/oauth2-svc-authn)
   

5. Create worktree:
   • Default location (unless directed otherwise): $repoRoot/.worktrees/[friendly-name]
   • Branch from main/master
   • Follow using-git-worktrees skill for safety verification and setup
6. Change to worktree directory
7. Announce: “Worktree created at .worktrees/[friendly-name] on branch [branch-name]“

If user chooses “No – work in current directory”:

1. Ask user which branch to use:

   Question: "Which branch should I use for this implementation?"
   Options:
     - "Use current branch" (stay on current branch, no branch creation)
     - "[friendly-name]" (e.g., oauth2-svc-authn)
     - "$(whoami)/[friendly-name]" (e.g., ed/oauth2-svc-authn)
   

2. If “Use current branch”: Continue with current branch (no git commands)
3. If branch name provided:
   • Determine main branch name: Check if main or master exists
   • Create new branch from main/master: git checkout -b [branch-name] origin/[main-or-master]
   • Verify branch created successfully
   • Announce: “Created and checked out branch [branch-name] from origin/[main-or-master]“
4. If branch creation fails: Report error to user and ask if they want to use current branch instead

Mark “Branch setup” task as completed. THEN proceed to Planning.

Check for Implementation Guidance

After branch setup, check for project-specific implementation guidance.

Check if .ed3d/implementation-plan-guidance.md exists:

Use the Read tool to check if .ed3d/implementation-plan-guidance.md exists in the session’s working directory.

If the file exists:

1. Use TaskCreate to add: “Read project implementation guidance from [absolute path to .ed3d/implementation-plan-guidance.md]”
   • Set this task as blocked by “Branch setup”
   • Update “Create implementation plan” to be blocked by this new task
2. Mark the task in_progress
3. Read the file and incorporate the guidance into your understanding
4. Mark the task completed
5. Proceed to Planning

If the file does not exist:

Proceed directly to Planning. Do not create a task or mention the missing file.

What implementation guidance provides:

• Coding standards and conventions
• Testing requirements and patterns
• Review criteria beyond defaults
• Project-specific quality gates

Planning

Mark “Create implementation plan” task as in_progress.

REQUIRED SUB-SKILL: Use ed3d-plan-and-execute:writing-implementation-plans

Announce: “I’m using the writing-implementation-plans skill to create the detailed implementation plan.”

The writing-implementation-plans skill will:

• Verify scope (<=8 phases from design plan)
• Verify codebase state with investigator
• Create phase-by-phase implementation tasks
• Validate each phase with user before proceeding
• Write implementation plan to docs/implementation-plans/

Output: Complete implementation plan written to files, on appropriate branch.

Mark “Create implementation plan” task as completed.

After Planning: Update Dependencies

CRITICAL: Update the “Re-read skill” task to be blocked by Finalization.

The granular tasks are now created. Find the Finalization task ID and update dependencies:

TaskUpdate: "Re-read starting-an-implementation-plan skill"
  → addBlockedBy: [Finalization task ID]

This ensures the task list shows the correct order:

✔ #1 Branch setup
✔ #2 Create implementation plan
✔ #5 Phase 1A: Read [Phase Name] from /path/to/design.md
✔ #6 Phase 1B: Investigate codebase for Phase 1
...
✔ #N Finalization: Run code-reviewer...
◻ #3 Re-read skill › blocked by #N
◻ #4 Execution handoff › blocked by #3

Restore Context (Before Handoff)

Mark “Re-read starting-an-implementation-plan skill (restore context)” task as in_progress.

CRITICAL: Re-read this skill before proceeding to handoff.

After potentially long planning work (especially if context compaction occurred), re-read this skill file to ensure you have accurate instructions for the execution handoff:

# Re-read this skill to restore context
cat /path/to/plugins/ed3d-plan-and-execute/skills/starting-an-implementation-plan/SKILL.md

Or use the Read tool on the skill file path.

Why this matters: After compaction, you may have lost details about the handoff process. Re-reading ensures you provide correct absolute paths and instructions.

Mark “Re-read starting-an-implementation-plan skill” task as completed.

Execution Handoff

Mark “Execution handoff” task as in_progress.

After planning is complete, hand off to execution.

Do NOT invoke execute-plan directly. The user needs to /clear context first.

Step 1: Capture and verify absolute paths

Before outputting the handoff instructions, you MUST run these commands to get real, verified paths:

# Get absolute path to current working tree root
git rev-parse --show-toplevel

Capture this output as WORKING_ROOT.

Then construct and verify the implementation plan path exists:

# Verify implementation plan directory exists
# Replace YYYY-MM-DD-feature-name with the actual plan directory name
ls -d "${WORKING_ROOT}/docs/implementation-plans/YYYY-MM-DD-feature-name"

Both commands must succeed. If the plan directory doesn’t exist, something went wrong during planning — investigate before proceeding.

Step 2: Provide copy-paste instructions with verified absolute paths

Use the actual paths you captured and verified in Step 1. Example output:

Implementation plan complete!

Ready to execute? This requires fresh context to work effectively.

**IMPORTANT: Copy the command below BEFORE running /clear (it will erase this conversation).**

(1) Copy this command now:

/ed3d-plan-and-execute:execute-implementation-plan /Users/ed/project/.worktrees/oauth2-feature/docs/implementation-plans/2025-01-17-oauth2-feature/ /Users/ed/project/.worktrees/oauth2-feature/

(2) Clear your context:

/clear

(3) Paste and run the copied command.

The execute-implementation-plan command will implement the plan task-by-task with code review between tasks.

Use the real paths from Step 1, not placeholders. The example above shows the format — substitute your actual verified paths.

Why absolute paths: After /clear, Claude Code returns to the original session directory (often the repo root, not the worktree). Absolute paths ensure execution happens in the correct directory regardless of where /clear returns.

Why /clear instead of continuing:

• Execution needs fresh context to work effectively
• Long conversations accumulate context that degrades quality
• /clear gives the execution phase a clean slate

Mark “Execution handoff” task as completed.

Common Mistakes

Integration with Workflow

This skill sits between design and execution:

Design Plan (in docs/design-plans/)
  -> User runs /start-implementation-plan with design path

Starting Implementation Plan (this skill)
  -> Step 0: Create orchestration tasks
    -> [ ] Branch setup
    -> [ ] Create implementation plan
    -> [ ] Re-read skill (restore context)
    -> [ ] Execution handoff

  -> Branch Setup [tracked task]
    -> Ask if user wants worktree
    -> If yes: invoke using-git-worktrees
    -> If no: ask which branch, create if needed

  -> Planning [tracked task wrapping granular tasks]
    -> Invoke writing-implementation-plans
    -> Creates granular tasks per phase (NA, NB, NC, ND)
    -> Creates Finalization task (code review, fix ALL issues)
    -> Write to docs/implementation-plans/

  -> After Planning: Update Dependencies
    -> Re-point "Re-read skill" to be blocked by Finalization task
    -> Ensures correct execution order in task list

  -> Restore Context [tracked task, blocked by Finalization]
    -> Re-read this skill file
    -> Ensures handoff instructions are accurate post-compaction

  -> Execution Handoff [tracked task]
    -> Run `git rev-parse --show-toplevel` for absolute paths
    -> Verify plan directory exists
    -> Output command with verified absolute paths
    -> Provide /clear command

Execute Implementation Plan (next step)
  -> Reads implementation plan
  -> Implements task-by-task
  -> Code review between tasks

Purpose: Bridge design and execution with appropriate branch isolation, granular task tracking that survives compaction, and context restoration.