spec-workflow

A structured feature-planning workflow that turns an idea into requirements, a technical design, and an ordered task list. Spec-driven development means planning and tracing the work before implementation.

In plain words
What is it for?
Use it to explore an idea, write user stories and requirements, design a solution, and break the work into trackable tasks.
Why use it?
It reduces ad-hoc coding by making the intended behavior, architecture, and implementation steps explicit before code is written.

Skill for Claude CodeCodex

Part of the spec-driven plugin — 1 skill, 19 commands, 12 agents shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/habib0x0/spec-driven-plugin/spec-workflow
Any agent
npx skills add Habib0x0/spec-driven-plugin --skill spec-workflow
Clone the repo
git clone --depth 1 https://github.com/Habib0x0/spec-driven-plugin

Made for: Claude Code, Codex.

Or install spec-driven, the plugin that ships this one along with the rest of its 1 skill, 19 commands, 12 agents.

Per session 92 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,919 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00092 $0.01919
Opus 5 $0.00046 $0.00959
Sonnet 5 $0.00018 $0.00384
Haiku 4.5 $0.00009 $0.00192

Measured 2d ago against content hash 0a9c63a70a4b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec-workflow scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/spec-workflow/SKILL.md · 270 lines

How it starts

The opening of the file, as written. The whole thing — 270 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spec-Driven Development Workflow

A structured approach to feature development through four phases: Brainstorm, Requirements, Design, and Tasks. This methodology prevents ad-hoc coding by ensuring proper planning before implementation.

Overview

Spec-driven development transforms vague feature ideas into formal, traceable specifications:

Feature Idea → Brainstorm (Conversation) → Requirements (EARS) → Design (Architecture) → Tasks (Trackable)

Phase 0: Brainstorm

Before formalizing requirements, use /spec-brainstorm to explore the idea through conversation.

When to Brainstorm

  • You have a vague idea that needs refinement
  • You're weighing multiple approaches
  • You want to think through feasibility before committing
  • The scope isn't clear yet

Brainstorm Workflow

  1. Start with /spec-brainstorm [idea]
  2. Have a back-and-forth conversation exploring the problem
  3. Codex asks probing questions, suggests alternatives, identifies gaps
  4. When the idea is solid, Codex outputs a brief
  5. Use that brief as input for /spec <feature-name>

The brainstorm phase is optional — if you already know exactly what you want, skip straight to /spec.

All new spec files are stored in .claude/specs/<feature-name>/. Existing .codex/specs/<feature-name>/ specs remain supported as a migration fallback:

  • requirements.md - User stories with EARS acceptance criteria
  • design.md - Architecture, components, data flow
  • tasks.md - Implementation tasks tracked by status, wiring, verification, and dependencies

Phase 1: Requirements

Capture WHAT the system should do using EARS (Easy Approach to Requirements Syntax).

EARS Notation

Structure requirements as testable statements:

WHEN [condition/trigger]
THE SYSTEM SHALL [expected behavior]

Examples:

WHEN a user submits a login form with valid credentials
THE SYSTEM SHALL authenticate the user and redirect to dashboard

WHEN a user submits invalid form data
THE SYSTEM SHALL display inline validation errors without page reload

WHEN an API request fails after 3 retries
THE SYSTEM SHALL display a user-friendly error message and log the failure

Read the full file on GitHub · 270 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 270 lines · 92 tokens per session scan A 0a9c63a70a4b

Subscribe to this mod's changes

spec-workflow is a skill published in the GitHub repository Habib0x0/spec-driven-plugin (10 stars, last pushed 3mo ago), licensed MIT. It adds 92 tokens to every session and 1,919 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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