Structured Development Plans with Coding Agents

A Claude Code skill that generates structured development plans as markdown files. Claude already creates internal plans that it writes to ~/.claude/plans but it overwrites them as the work goes through phases. Think of this skill as a way to capture your conversations and decisions vis-a-vis the coding agent's perspective. If the output veers too far from your expectations, you can have a conversation with the coding agent to adjust the plan. Think of this as a way to capture the Software Development Life Cycle (SDLC) phases, design -> build -> fix -> improve, sometimes trash and repeat knowing what you have learned.

At the heart of it, The Dev Plans live in the repo (docs/dev_plans/), so they double as lightweight design docs. The checklist format makes it easy to track progress across sessions, and the issues section captures decisions you would otherwise forget. For larger features,the checklist of tasks can be organised in phases, Lastly, all good plans need to identify task dependencies, so that they can be executed independently by subagents. The skill produces a timestamped markdown file in docs/dev_plans/ (e.g. 20251012-trail-claudes-jsonl-files.md) with:

• Header — status, branch, priority, dates
• Context & Requirements — the why and what
• Implementation Checklist — phased tasks with checkboxes and interdependencies
  • Technical Specs — files to touch, interfaces, decisions
  • Testing & Issues — test approach, problems hit, solutions found
  • Acceptance Criteria — definition of done for each task and phase

/dev-plan create feature auth-system   # new plan
/dev-plan update                       # update current plan
/dev-plan complete                     # mark done
/dev-plan list                         # list all plans

Updated (2025-11-17): Figured out Git Worktrees, now you can spawn agents that work on different branches.
Updated (2026-01-27): Using the fan-out skill to spawn subagents for each independent task.