Spec Kit Plan Skill
When to Use
- The feature spec is ready and you need a technical implementation plan.
Inputs
specs/<feature>/spec.md- Repo context and
.specify/templates - User-provided constraints or tech preferences (if any)
If the spec is missing, ask the user to run speckit-specify first.
Workflow
- Setup: Run
.specify/scripts/bash/setup-plan.sh --jsonfrom repo root and parse JSON for FEATURE_SPEC, IMPL_PLAN, SPECS_DIR, BRANCH. For single quotes in args like "I'm Groot", use escape syntax: e.g 'I'''m Groot' (or double-quote if possible: "I'm Groot"). - Load context: Read FEATURE_SPEC and
.specify/memory/constitution.md. Load IMPL_PLAN template (already copied). - Execute plan workflow: Follow the structure in IMPL_PLAN template to:
- Fill Technical Context (mark unknowns as "NEEDS CLARIFICATION") - Fill Constitution Check section from constitution - Evaluate gates (ERROR if violations unjustified) - Phase 0: Generate research.md (resolve all NEEDS CLARIFICATION) - Phase 1: Generate data-model.md, contracts/, quickstart.md - Phase 1: Update agent context by running the agent script - Re-evaluate Constitution Check post-design
- Stop and report: Command ends after Phase 2 planning. Report branch, IMPL_PLAN path, and generated artifacts.
Phases
Phase 0: Outline & Research
- Extract unknowns from Technical Context above:
- For each NEEDS CLARIFICATION → research task - For each dependency → best practices task - For each integration → patterns task
- Generate and dispatch research agents:
For each unknown in Technical Context: Task: "Research {unknown} for {feature context}" For each technology choice: Task: "Find best practices for {tech} in {domain}" - Consolidate findings in
research.mdusing format:
- Decision: [what was chosen] - Rationale: [why chosen] - Alternatives considered: [what else evaluated]
Output: research.md with all NEEDS CLARIFICATION resolved
Phase 1: Design & Contracts
Prerequisites: research.md complete
- Extract entities from feature spec →
data-model.md:
- Entity name, fields, relationships - Validation rules from requirements - State transitions if applicable
- Generate API contracts from functional requirements:
- For each user action → endpoint - Use standard REST/GraphQL patterns - Output OpenAPI/GraphQL schema to /contracts/
- Agent context update:
- Run .specify/scripts/bash/update-agent-context.sh <agent_type> - Use the current runtime agent type (e.g., claude, codex, copilot, gemini). Leave empty to update all existing agent files. - Update the appropriate agent-specific context file - Add only new technology from current plan - Preserve manual additions between markers
Output: data-model.md, /contracts/*, quickstart.md, agent-specific file
Key rules
- Use absolute paths
- ERROR on gate failures or unresolved clarifications
Outputs
specs/<feature>/plan.md(filled implementation plan)specs/<feature>/research.mdspecs/<feature>/data-model.mdspecs/<feature>/contracts/(API schemas)specs/<feature>/quickstart.md- Updated agent context file (runtime-specific)
Next Steps
After planning:
- Generate tasks with speckit-tasks.
- Create a checklist with speckit-checklist when a quality gate is needed.