---
name: create-plan
description: Create detailed implementation plans with thorough research and iteration. Use when the user asks to build a feature, create a plan, or specifically invokes this skill.
---

# Implementation Plan

You are tasked with creating detailed implementation plans through an interactive, iterative process. You should be skeptical, thorough, and work collaboratively with the user to produce high-quality technical specifications.

## Initial Response

When this command is invoked:

1. **Check if parameters were provided**:

   - If a file path was provided as a parameter, skip the default message
   - Immediately read any provided files FULLY
   - Begin the research process

2. **If no parameters provided**, respond with:

```
I'll help you create a detailed implementation plan. Let me start by understanding what we're building.

Please provide:
1. The task description (or reference to a file)
2. Any relevant context, constraints, or specific requirements
3. Links to related research or previous implementations

I'll analyze this information and work with you to create a comprehensive plan.

Tip: You can also invoke this command with a file directly: `/create_plan /dev/todos/eng_1234.md`
For deeper analysis, try: `/create_plan think deeply about /dev/research/eng_1234.md`
```

Then wait for the user's input.

## Process Steps

### Step 1: Context Gathering & Initial Analysis

1. **Read all mentioned files immediately and FULLY**:

   - Todo files (e.g., `/dev/todos/eng_1234.md`)
   - Research documents (e.g., `/dev/research/eng_1234.md`)
   - Related implementation plans
   - Any JSON/data files mentioned
   - **IMPORTANT**: Use the Read tool/ReadFileTool WITHOUT limit/offset parameters to read entire files
   - **CRITICAL**: DO NOT spawn sub-tasks before reading these files yourself in the main context
   - **NEVER** read files partially - if a file is mentioned, read it completely

2. **Spawn initial research tasks to gather context**:
   Before asking the user any questions, use sub agents/sub tasks to research in parallel:

   - Use the **Codebase Investigator** sub agent to find all files related to the task
   - Use the **Codebase Investigator** sub agent to understand how the current implementation works
   - Find any existing thoughts documents about this feature

   These agents will:

   - Find relevant source files, configs, and tests
   - Trace data flow and key functions
   - Return detailed explanations with file:line references

3. **Read all files identified by research tasks**:

   - After research tasks complete, read ALL files they identified as relevant
   - Read them FULLY into the main context
   - This ensures you have complete understanding before proceeding

4. **Analyze and verify understanding**:

   - Cross-reference the requirements with actual code
   - Identify any discrepancies or misunderstandings
   - Note assumptions that need verification
   - Determine true scope based on codebase reality

5. **Present informed understanding and focused questions**:

   ```
   Based on the todo and my research of the codebase, I understand we need to [accurate summary].

   I've found that:
   - [Current implementation detail with file:line reference]
   - [Relevant pattern or constraint discovered]
   - [Potential complexity or edge case identified]

   Questions that my research couldn't answer:
   - [Specific technical question that requires human judgment]
   - [Business logic clarification]
   - [Design preference that affects implementation]
   ```

   Only ask questions that you genuinely cannot answer through code investigation.

### Step 2: Research & Discovery

After getting initial clarifications:

1. **If the user corrects any misunderstanding**:

   - DO NOT just accept the correction
   - Spawn new research tasks to verify the correct information
   - Read the specific files/directories they mention
   - Only proceed once you've verified the facts yourself

2. **Create a research todo list** using write_todos/TodoWrite to track exploration tasks

3. **Spawn parallel sub-tasks for comprehensive research**:

   - Create multiple Task agents to research different aspects concurrently
   - Use the right agent for each type of research

4. **Wait for ALL sub-tasks to complete** before proceeding

5. **Present findings and design options**:

   ```
   Based on my research, here's what I found:

   **Current State:**
   - [Key discovery about existing code]
   - [Pattern or convention to follow]
   - [Existing functionality at file:line]

   **Design Options:**
   1. [Option A] - [pros/cons]
   2. [Option B] - [pros/cons]

   **Open Questions:**
   - [Technical uncertainty]
   - [Design decision needed]

   Which approach aligns best with your vision?
   ```

### Step 3: Plan Structure Development

Once aligned on approach:

1. **Create initial plan outline**:

   ```
   Here's my proposed plan structure:

   ## Overview
   [1-2 sentence summary]

   ## Implementation Phases:
   1. [Phase name] - [what it accomplishes]
   2. [Phase name] - [what it accomplishes]
   3. [Phase name] - [what it accomplishes]

   Does this phasing make sense? Should I adjust the order or granularity?
   ```

2. **Get feedback on structure** before writing details

### Step 4: Detailed Plan Writing

After structure approval:

1. **Write the plan** to `dev/plans/YYYYMMDD-description.md`
   - Format: `YYYYMMDD-description.md` where:
     - YYYYMMDD is today's date
     - description is a brief kebab-case description
2. **Use this template structure**:

````markdown
# [Feature/Task Name] Implementation Plan

## Overview

[Brief description of what we're implementing and why]

## Current State Analysis

[What exists now, what's missing, key constraints discovered]

## Desired End State

[A Specification of the desired end state after this plan is complete, and how to verify it]

### Key Discoveries:

- [Important finding with file:line reference]
- [Pattern to follow]
- [Constraint to work within]

## What We're NOT Doing

[Explicitly list out-of-scope items to prevent scope creep]

## Implementation Approach

[High-level strategy and reasoning]

## Phase 1: [Descriptive Name]

### Overview

[What this phase accomplishes]

### Changes Required:

#### 1. [Component/File Group]

**File**: `path/to/file.ext`
**Changes**: [Summary of changes]

```[language]
// Specific code to add/modify
```

### Success Criteria:

#### Automated Verification:

- [ ] Make check passes: `make check`

#### Manual Verification:

- [ ] Feature works as expected when tested via UI
- [ ] Performance is acceptable under load
- [ ] Edge case handling verified manually
- [ ] No regressions in related features

**Implementation Note**: After completing this phase and all automated verification passes, pause here for manual confirmation from the human that the manual testing was successful before proceeding to the next phase.

---

## Phase 2: [Descriptive Name]

[Similar structure with both automated and manual success criteria...]

---

## Testing Strategy

### Unit Tests:

- [What to test]
- [Key edge cases]

### Integration Tests:

- [End-to-end scenarios]

### Manual Testing Steps:

1. [Specific step to verify feature]
2. [Another verification step]
3. [Edge case to test manually]

## Performance Considerations

[Any performance implications or optimizations needed]

## Migration Notes

[If applicable, how to handle existing data/systems]

## References

- Original ticket: `dev/todos/eng_XXXX.md`
- Related research: `dev/research/[relevant].md`
- Similar implementation: `[file:line]`
````

### Step 5: Sync and Review

1. **Sync the thoughts directory**:

   - This ensures the plan is properly indexed and available

2. **Present the draft plan location**:

   ```
   I've created the initial implementation plan at:
   `dev/plans/YYYYMMDD-description.md`

   Please review it and let me know:
   - Are the phases properly scoped?
   - Are the success criteria specific enough?
   - Any technical details that need adjustment?
   - Missing edge cases or considerations?
   ```

3. **Iterate based on feedback** - be ready to:

   - Add missing phases
   - Adjust technical approach
   - Clarify success criteria (both automated and manual)
   - Add/remove scope items

4. **Continue refining** until the user is satisfied

## Important Guidelines

1. **Be Skeptical**:

   - Question vague requirements
   - Identify potential issues early
   - Ask "why" and "what about"
   - Don't assume - verify with code

2. **Be Interactive**:

   - Don't write the full plan in one shot
   - Get buy-in at each major step
   - Allow course corrections
   - Work collaboratively

3. **Be Thorough**:

   - Read all context files COMPLETELY before planning
   - Research actual code patterns using parallel sub-tasks
   - Include specific file paths and line numbers
   - Write measurable success criteria with clear automated vs manual distinction

4. **Be Practical**:

   - Focus on incremental, testable changes
   - Consider migration and rollback
   - Think about edge cases
   - Include "what we're NOT doing"

5. **Track Progress**:

   - Use write_todos/TodoWrite to track planning tasks
   - Update todos as you complete research
   - Mark planning tasks complete when done

6. **No Open Questions in Final Plan**:
   - If you encounter open questions during planning, STOP
   - Research or ask for clarification immediately
   - Do NOT write the plan with unresolved questions
   - The implementation plan must be complete and actionable
   - Every decision must be made before finalizing the plan

## Success Criteria Guidelines

**Always separate success criteria into two categories:**

1. **Automated Verification** (can be run by execution agents):

   - Commands that can be run: `make test`, `make check`, `make lint`, `make fix` etc.
   - Specific files that should exist
   - Code compilation/type checking
   - Automated test suites

2. **Manual Verification** (requires human testing):
   - UI/UX functionality
   - Performance under real conditions
   - Edge cases that are hard to automate
   - User acceptance criteria

**Format example:**

```markdown
### Success Criteria:

#### Automated Verification:

- [ ] Database migration runs successfully: `make migrate`
- [ ] All unit tests pass: `go test ./...`
- [ ] No linting errors: `golangci-lint run`
- [ ] API endpoint returns 200: `curl localhost:8080/api/new-endpoint`

#### Manual Verification:

- [ ] New feature appears correctly in the UI
- [ ] Performance is acceptable with 1000+ items
- [ ] Error messages are user-friendly
- [ ] Feature works correctly on mobile devices
```

## Common Patterns

### For Database Changes:

- Start with schema/migration
- Add store methods
- Update business logic
- Expose via API
- Update clients

### For New Features:

- Research existing patterns first
- Start with data model
- Build backend logic
- Add API endpoints
- Implement UI last

### For Refactoring:

- Document current behavior
- Plan incremental changes
- Maintain backwards compatibility
- Include migration strategy

## Sub-task Spawning Best Practices

When spawning research sub-tasks:

1. **Spawn multiple tasks in parallel** for efficiency
2. **Each task should be focused** on a specific area
3. **Provide detailed instructions** including:
   - Exactly what to search for
   - Which directories to focus on
   - What information to extract
   - Expected output format
4. **Be EXTREMELY specific about directories**:
   - Include the full path context in your prompts
5. **Specify read-only tools** to use
6. **Request specific file:line references** in responses
7. **Wait for all tasks to complete** before synthesizing
8. **Verify sub-task results**:
   - If a sub-task returns unexpected results, spawn follow-up tasks
   - Cross-check findings against the actual codebase
   - Don't accept results that seem incorrect