spec-kit-plan

name	spec-kit-plan
description	Create a technical implementation plan from a feature spec. Documents architecture, data models, and interface contracts without generating code. Run after spec-kit-clarify.
license	MIT
compatibility	No external workflow CLI required.
metadata	{"author":"Aircury","version":"1.0"}

Create a technical implementation plan from a feature specification.

Input: Optionally specify a change name. If omitted, infer from context or ask.

Steps

1. Select the change and load artifacts

   Load specs/changes/<name>/spec.md. If it does not exist, prompt to use the spec-kit-specify skill first.

   Also load specs/features/ relevant to the area being changed.

2. Research unknowns

   If the spec contains unresolved [NEEDS CLARIFICATION] markers, pause and suggest using the spec-kit-clarify skill first unless the user explicitly wants to proceed.

3. Write specs/changes/<name>/plan.md

   Structure:

   # Plan: <Feature Name>
   
   ## Architecture
   <Bounded context, layers affected, dependency direction. Must comply with FRAMEWORK.md dependency rule.>
   
   ## Data Models
   <Entities, value objects, aggregates. Identity vs. structural equality. Invariants.>
   
   ## Interface Contracts
   <Ports, use case signatures, domain events. Technology-agnostic.>
   
   ## Implementation Phases
   1. <Phase name> — <what it establishes>
   2. ...
   
   ## Decisions & Rationale
   | Decision | Rationale | Alternatives Considered |
   |----------|-----------|------------------------|
   
   ## Constraints & Risks
   <Known constraints, open technical risks.>
   

   Rules:

   • Dependency direction must be infrastructure -> application -> domain. Never invert.
   • External dependencies affecting business behavior must sit behind ports.
   • Repositories are per aggregate root, not per table.
   • No framework names in domain or application layer design.
   • Cross-context communication via domain events or application services only.

4. Constitution check

   Before finishing, verify the plan does not violate any FRAMEWORK.md non-negotiable architecture rules.

Output

After writing the plan:

• Confirm file location.
• Highlight any architecture decisions worth the user's attention.
• Next step: "Use the spec-kit-tasks skill to generate the task list."

Guardrails

• No code generation — plan only.
• If the spec has unresolved clarifications that affect architecture, surface them rather than guessing.
• Protect the domain model first; adapt infrastructure around it.