OpenSpec

What it does

OpenSpec is an open-source command-line framework for creating and managing software specifications. You capture what you want to build as Markdown specs, including a proposal, requirements, a design document, and a task list, then use them to keep a team and AI coding agents aligned as the work changes. The workflow runs inside a supported AI coding tool rather than as a standalone app, with commands such as explore, propose, apply, verify, and archive.

People use OpenSpec to refine requirements before code is written, check that a proposal describes the intended change, and verify that the implementation matches the spec. Completed changes are archived, leaving a record of the system in plain Markdown that remains readable without the tool. The project lists compatibility with more than 40 AI coding tools, including Claude Code, Codex, Cursor, GitHub Copilot, and Gemini CLI.

OpenSpec suits developers and teams already working with AI coding assistants who want lightweight, reviewable specifications. It installs as a single binary with no Node.js requirement, or through npm, pnpm, bun, yarn, Homebrew, or Nix, and the project is MIT-licensed. Cost beyond the open-source CLI is not stated, and the workflow depends on a supported AI coding tool being available.

What it can do

• Create structured change proposals with proposal.md, specs, design.md, and tasks.md
• Explore the codebase and map a problem before proposing changes (/opsx:explore)
• Implement tasks from a specification (/opsx:apply)
• Verify that an implementation matches its spec (/opsx:verify)
• Archive completed changes while keeping them as readable Markdown (/opsx:archive)
• Configure per-project generated skills and commands with openspec init and openspec update

Works with

• Claude Code
• Codex
• Cursor
• GitHub Copilot
• Gemini CLI
• OpenCode
• Cline
• Continue
• Kiro
• Zed

Before you choose

• The workflow runs inside a supported AI coding tool, so you need one of those tools available.
• Generated skills and commands do not update automatically; run openspec update in each project to refresh them.
• Some installation methods require Node.js 20.19.0 or newer, while the standalone binary does not.

Listed under

• Coding
• MCP and agent tools
• AI coding agents
• CLI
• Developer tools
• Open source
• Requirements
• Spec-driven development

Get started

Standalone install, npm, Homebrew, Nix, and other methods are documented on the installation page.

1. Install the openspec CLI using the standalone script, npm, Homebrew, or another documented method, then confirm with openspec --version.
2. Navigate to your project folder and run openspec init to create the project setup.
3. Open your AI coding tool in that project and use the /opsx commands (explore, propose, apply, verify, archive) to run the workflow.

OpenSpec is released under the MIT license; any charges would come from the AI coding tool or model used alongside it, which the buyer should verify.

We couldn’t find published prices for OpenSpec.

Sources for this overview

Product pages, documentation, and pricing checked 29 Oct 2026. Each source supports part of the overview; availability and prices can change.

• OpenSpec | A lightweight and configurable spec framework ↗openspec.dev
• Installation | OpenSpec ↗openspec.dev

Company website

openspec.dev: product, pricing and policy pages

YC directory mirror

Batch and company name

Human review

Checked by a person

manual_review

Last checked 29 Oct 2026. Every field keeps its source and date; unknown means we couldn’t confirm it.