planner

Planner

Transforms vague feature ideas into structured, executable implementation plans with dependency graphs, risk analysis, and phased rollout strategies.

Level	L1 Vibe Coder
Category	Core Workflow
Model	Sonnet

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What It Does

The Planner is the strategic architect you wish you had on every project. When you say "I need OAuth" or "we should add real-time notifications," it does not jump to code. Instead, it runs a five-phase planning framework: requirements gathering, architecture design, task breakdown, risk analysis, and implementation strategy. Each phase produces concrete artifacts -- not handwavy recommendations, but actual plan files written to .claude/plans/ with YAML frontmatter, dependency graphs, and time estimates.

What makes the Planner valuable is what it encodes about good software planning. It enforces SOLID principles in every architecture it designs. It recommends clean architecture layers (Interface, Application, Domain, Infrastructure) with dependencies flowing inward. It insists on test strategies alongside implementation plans -- not as an afterthought, but as first-class tasks with coverage targets. It knows that a "simple" feature like user preferences actually involves schema design, migration strategy, API endpoints, validation, and frontend state management.

Without the Planner, you either start coding immediately and discover architectural problems mid-sprint, or you spend an hour sketching in a notebook that nobody references again. The Planner produces living documents that track progress, record decisions, and serve as contracts between you and the agents that execute the work.

When to Use It

• Starting a new feature from scratch: When you have an idea but no clear path from concept to production, the Planner decomposes it into a plan with task dependencies, time estimates, and risk mitigations.
• Facing a complex refactoring: When your database layer is tangled or your monolith needs breaking apart, the Planner creates a current-state analysis, target-state design, and a step-by-step transformation path with rollback strategies.
• Deciding between architectural approaches: When you need to choose between PostgreSQL and MongoDB, REST and GraphQL, or monolith and microservices, the Planner presents explicit trade-offs and recommends based on your project's constraints.
• Breaking down an epic into sprint-sized tasks: When a feature is too large for a single session, the Planner creates phased milestones with testable outcomes at each checkpoint.