How do I install the Openspec skill?

Run npx skillmds@latest add mahmoud20138/openspec in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Openspec safe to use?

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Which AI agents work with Openspec?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Openspec free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Openspec?

mahmoud20138 (@mahmoud20138) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Openspec by mahmoud20138 — Agent Skill

Name: Openspec
Author: mahmoud20138

Openspec

OpenSpec — lightweight fluid spec framework for AI-assisted development. USE FOR: "openspec", "opsx", "/opsx:propose", "propose feature", "spec before coding", "iterative spec", "brownfield spec", "AI spec framework", "change proposal", "design before implement", "fluid specs", "spec folder", "openspec init". Lighter alternative to spec-kit: no rigid phases, works on existing projects.

mahmoud20138 eba0649 2.7 KB Updated Sep 17, 2026

File contents

OpenSpec — Fluid Spec-Driven Development

"Fluid not rigid. Iterative not waterfall. Built for brownfield." Lighter alternative to Spec Kit — no phase gates, works on existing projects.

vs Spec Kit

	OpenSpec	Spec Kit
Style	Fluid, iterative	Structured, gated phases
Best for	Brownfield + greenfield	Greenfield projects
Phase gates	No	Yes (must complete each phase)
Commands	3 core + 8 extended	8 ordered commands
Install	npm global	uv/uvx
Models	Opus 4.5+ recommended	Any

Installation

npm install -g @fission-ai/openspec@latest
cd your-project
openspec init

# Opt out of telemetry
export OPENSPEC_TELEMETRY=0

Core 3-Command Workflow

1. /opsx:propose "feature name"  → generates change folder
2. /opsx:apply                   → AI implements tasks
3. /opsx:archive                 → moves to archive

Change Folder Structure

.openspec/changes/<feature-name>/
├── proposal.md     ← rationale and scope
├── specs/          ← requirements and scenarios
├── design.md       ← technical approach
└── tasks.md        ← implementation checklist

All Commands

Command	Purpose
`/opsx:propose "idea"`	Create new change folder with proposal + specs + design + tasks
`/opsx:apply`	Implement tasks from current change
`/opsx:archive`	Archive completed change
`/opsx:new`	Start fresh change
`/opsx:continue`	Resume in-progress change
`/opsx:ff`	Fast-forward (skip to implementation)
`/opsx:verify`	Validate implementation against spec
`/opsx:sync`	Synchronize agent instructions
`/opsx:bulk-archive`	Archive multiple completed changes
`/opsx:onboard`	Team onboarding setup

CLI Commands

openspec init              # initialize in project
openspec config profile    # select workflow type
openspec update            # refresh agent instructions + slash commands

Key Principles

No phase gates — update any artifact at any time
Brownfield first — works on existing codebases
Context management — clear context before implementation phases
Best with Opus 4.5+ — high-reasoning models get best results
20+ AI tools — Claude Code, Cursor, Copilot, Windsurf, etc.

---name: openspecdescription: OpenSpec — lightweight fluid spec framework for AI-assisted development. USE FOR: "openspec", "opsx", "/opsx:propose", "propose feature", "spec before coding", "iterative spec", "brownfield spec", "AI spec framework", "change proposal", "design before implement", "fluid specs", "spec folder", "openspec init". Lighter alternative to spec-kit: no rigid phases, works on existing projects.---# OpenSpec — Fluid Spec-Driven Development> "Fluid not rigid. Iterative not waterfall. Built for brownfield."> Lighter alternative to Spec Kit — no phase gates, works on existing projects.## vs Spec Kit| | OpenSpec | Spec Kit ||--|---------|---------|| Style | Fluid, iterative | Structured, gated phases || Best for | Brownfield + greenfield | Greenfield projects || Phase gates | No | Yes (must complete each phase) || Commands | 3 core + 8 extended | 8 ordered commands || Install | npm global | uv/uvx || Models | Opus 4.5+ recommended | Any |## Installation```bashnpm install -g @fission-ai/openspec@latestcd your-projectopenspec init# Opt out of telemetryexport OPENSPEC_TELEMETRY=0```## Core 3-Command Workflow```1. /opsx:propose "feature name" → generates change folder2. /opsx:apply → AI implements tasks3. /opsx:archive → moves to archive```## Change Folder Structure```.openspec/changes/<feature-name>/├── proposal.md ← rationale and scope├── specs/ ← requirements and scenarios├── design.md ← technical approach└── tasks.md ← implementation checklist```## All Commands| Command | Purpose ||---------|---------|| `/opsx:propose "idea"` | Create new change folder with proposal + specs + design + tasks || `/opsx:apply` | Implement tasks from current change || `/opsx:archive` | Archive completed change || `/opsx:new` | Start fresh change || `/opsx:continue` | Resume in-progress change || `/opsx:ff` | Fast-forward (skip to implementation) || `/opsx:verify` | Validate implementation against spec || `/opsx:sync` | Synchronize agent instructions || `/opsx:bulk-archive` | Archive multiple completed changes || `/opsx:onboard` | Team onboarding setup |## CLI Commands```bashopenspec init # initialize in projectopenspec config profile # select workflow typeopenspec update # refresh agent instructions + slash commands```## Key Principles- **No phase gates** — update any artifact at any time- **Brownfield first** — works on existing codebases- **Context management** — clear context before implementation phases- **Best with Opus 4.5+** — high-reasoning models get best results- **20+ AI tools** — Claude Code, Cursor, Copilot, Windsurf, etc.

Frequently asked questions