- name
- openspec
- description
- 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.
- kind
- tool
- category
- ai/spec
- repo
- https://github.com/Fission-AI/OpenSpec
- related_skills
- ["spec-kit","ai-agent-builder","claude-md-improver"]
- tags
- ["spec-driven","ai-coding","planning","iterative","brownfield"]
- status
- active
# 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
```bash
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
```bash
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.
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