spec-specify

Generates feature specifications with user stories, Gherkin scenarios, Mermaid flowcharts, and acceptance criteria.

Updated Mar 11, 2026
One-click install
npx skills add https://github.com/julien-m/livespec --skill spec-specify-julien-m
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: spec-specify
Source: https://github.com/julien-m/livespec/tree/main/.agent-sync/skills/spec-specify
Command: npx skills add https://github.com/julien-m/livespec --skill spec-specify-julien-m

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Writing feature specifications manually produces inconsistent documents that lack traceability, visual flows, and testable acceptance criteria, and they quickly drift out of sync with the codebase. ## Core Features & Use Cases - Structured Spec Generation: Creates a complete spec.md with prioritized user stories, Gherkin scenarios, Mermaid flowcharts, numbered acceptance criteria (AC), and functional requirements (FR) under .specs/features/NNN-feature-name/. - Scope Analysis and Splitting: Detects when a request covers multiple independent domains, proposes a split, and writes seed.md files preserving context for deferred sub-features. - Behavioral and UI Contract Injection: Detects UI behavioral traits from a taxonomy and injects Gherkin acceptance criteria, plus resolves Penflow UI contracts for interface features. - Use Case: A product engineer runs the command with a feature description like "user notifications" and receives a validated, numbered feature spec with stories, diagrams, and testable criteria, with the roadmap and changelogs updated automatically. ## Quick Start Ask the AI to run /spec-specify with a feature description such as "user can receive real-time notifications" to generate a complete validated feature spec.

Frequently Asked Questions about spec-specify

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I create a feature specification with user stories and acceptance criteria?

Run /spec-specify with a feature description, and it generates a spec.md containing prioritized user stories, Gherkin scenarios, Mermaid flowcharts, numbered acceptance criteria, and functional requirements in .specs/features/NNN-feature-name/.

What happens when a feature request is too broad to specify?

The command performs scope analysis to detect independent domains and complexity thresholds. If a split is detected, it proposes specifying one domain now and writes seed.md files preserving context for the deferred sub-features in the roadmap.

Does spec-specify support UI features with behavioral testing?

Yes, it detects UI behavioral traits via a taxonomy and injects Gherkin acceptance criteria into a Behavioral AC section, including visual state assertions. It also resolves Penflow UI contracts for interface features.

Why does spec-specify fail with a validation error after generating the spec?

The generated spec.md is checked with livespec validate, and failures trigger regeneration with the error output as constraints. After two failed retries the command aborts and asks you to fix the spec manually.

What are the prerequisites for running spec-specify?

The project must have .specs/project.md initialized, typically via /spec-init, and you must supply a feature description as an argument. An active goal lock is also established before any task executes.