What problem does it solve? Complex implementation tasks often need deeper reasoning than a quick in-context answer provides. This Skill offloads planning to a dedicated Claude Opus Plan subagent prompted with "ultrathink", producing thorough, file-grounded implementation plans saved to disk. ## Core Features & Use Cases - Deep Reasoning Delegation: Launches a Plan subagent running on the Opus model with an ultrathink prompt to maximize reasoning depth via prompting rather than the extended thinking API. - Context-Aware Planning: Passes the task description plus relevant conversation context (files, constraints, goals) so the subagent reads actual code before recommending changes. - Persistent Plan Output: Writes the full plan to a timestamped Markdown file under ./tmp for later reference. - Use Case: Before refactoring a large module, invoke /opus-plan to get a step-by-step implementation plan with file paths, risks, trade-offs, and open questions. ## Quick Start Invoke /opus-plan with a description of the implementation task you want planned, or ask for a deep implementation plan for your current problem.
