Speckit Plan Skill for Codex

Speckit Plan Skill

User Input

$ARGUMENTS

You MUST consider the user input before proceeding (if not empty).

Outline

• Setup: Run .specify/scripts/powershell/setup-plan.ps1 -Json from 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.md using 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

• Define interface contracts (if project has external interfaces) → /contracts/:
• Identify what interfaces the project exposes to users or other systems
• Document the contract format appropriate for the project type
• Examples: public APIs for libraries, command schemas for CLI tools, endpoints for web services, grammars for parsers, UI contracts for applications
• Skip if project is purely internal (build scripts, one-off tools, etc.)

• Agent context update:
• Run .specify/scripts/powershell/update-agent-context.ps1 -AgentType codex
• These scripts detect which AI agent is in use
• 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