Speckit Baseline Agent Skill

Spec Kit Baseline Skill

When to Use

• You need a spec for existing or legacy code.
• You want to document a feature before refactoring.
• You inherited a codebase without written requirements.

Inputs

• A target path, file list, or glob pattern describing the code to analyze.
• Repo context with .specify/ scripts and templates.

If the target is missing or ambiguous, ask a focused question before continuing.

Goal

Generate a technology-agnostic spec for existing code, then create the feature branch/spec file using the standard Spec Kit templates.

Workflow

• Parse target input: Identify files, directories, or patterns to analyze.
• Accept file paths, glob patterns, or directory paths.
• If empty: stop and ask for a concrete target.

• Discover and read source files:
• Expand globs to a file list.
• Read file contents for analysis.
• Identify primary language(s) and frameworks.
• Map key file relationships and dependencies.

• Analyze code structure:
• Identify entry points and public interfaces.
• Extract function/method signatures and behaviors.
• Find data models and entities.
• Detect API endpoints and routes.
• Identify user-facing functionality.

• Generate a short name (2-4 words) from the analyzed code:
• Use action-noun format (e.g., "user-auth", "payment-processing").
• Base on primary functionality discovered.
• Preserve technical terms where meaningful.

• Create the feature branch and spec file:
• Find the highest existing feature number for this short name (branches/specs).
• Run .specify/scripts/bash/create-new-feature.sh --json with the calculated number and short name.
• Read BRANCH_NAME, FEATURE_DIR, and SPEC_FILE paths from the script JSON output.
• 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 the spec template from .specify/templates/spec-template.md.

• Draft the specification using the template structure:
• User Stories: Infer from user-facing code paths and interactions.
• Acceptance Scenarios: Derive from validation logic, error handling, and tests.
• Functional Requirements: Extract from business rules and constraints.
• Key Entities: Identify from data models and schemas.
• Success Criteria: Infer from metrics, logging, or performance-related code.
• Assumptions: Document inferences made during analysis.

• Abstract implementation details:
• Convert technical patterns to user-focused requirements.
• Remove framework-specific terminology.
• Focus on WHAT the code does, not HOW it does it.

• Create spec quality checklist at FEATURE_DIR/checklists/requirements.md.

10. Report completion with:

• Branch name and spec file path.
• Summary of analyzed files.
• Key features discovered.
• Areas needing clarification or review.

Outputs

• specs/<feature>/spec.md
• specs/<feature>/checklists/requirements.md

Key rules

• Focus on extracting WHAT and WHY from HOW.
• Abstract away implementation details in the generated spec.
• Document assumptions made during code analysis.
• Flag areas where code behavior is unclear.
• Preserve discovered business rules and constraints.
• Use [NEEDS CLARIFICATION] for ambiguous code sections (max 3).
• Generated specs should be validated by someone who knows the feature.

Examples

Code Pattern → Spec Requirement:

• if (user.role === 'admin') → "System MUST restrict action to administrator users"
• password.length >= 8 → "Passwords MUST be at least 8 characters"
• cache.set(key, value, 3600) → "System MUST cache results for improved performance"
• try { ... } catch (e) { notify(e) } → "System MUST notify users when errors occur"

Code Pattern → User Story:

• Login endpoint with OAuth → "As a user, I can sign in using my social account"
• Shopping cart logic → "As a customer, I can add items to my cart for later purchase"
• Report generation → "As an analyst, I can generate reports on system activity"

Next Steps

After generating spec.md:

• Clarify with domain experts using speckit-clarify.
• Plan modernization/refactoring with speckit-plan.
• Compare the generated spec with actual requirements to identify gaps.