OpenSpec OpenSpec
OpenSpec is a lightweight Spec-Driven Development (SDD) framework that acts as an agreement layer between you and your AI coding assistant. After `openspec init`, slash commands drive the workflow: `/opsx:explore` is a no-stakes thinking partner that reads your code and shapes a plan, `/opsx:propose` creates a per-change folder under `openspec/changes/` containing `proposal.md`, `specs/`, `design.md`, and `tasks.md` for you to review before any code is written, `/opsx:apply` implements the task checklist, and `/opsx:archive` folds the change back into the living specs in `openspec/specs/`. Specs are plain Markdown requirements (SHALL) with WHEN/THEN scenarios and no special syntax. An expanded profile adds `/opsx:new`, `/opsx:continue`, `/opsx:ff`, `/opsx:verify`, `/opsx:bulk-archive`, and `/opsx:onboard`; Stores (beta) move planning into a shared repo so cross-repo features and platform-owned requirements have one source of truth every coding agent can read. It works with 20+ assistants including Claude Code, Cursor, GitHub Copilot, Windsurf, Cline, RooCode, Codex, and Amazon Q.
v1.13.1 released 2026-09-17; ~69k GitHub stars, 110+ contributors, and trending on GitHub (daily) in mid-September 2026 after the rebuilt artifact-guided `/opsx` workflow and Stores beta.
As of
- Artifact-guided workflow: /opsx:explore → propose → apply → archive
- Per-change proposal.md, specs/, design.md, and tasks.md reviewed before code is written
- Plain-Markdown SHALL/WHEN/THEN specs versioned alongside code
- Iterative, brownfield-friendly: update any artifact anytime, no rigid phase gates
- Stores (beta) for cross-repo, team-shared specs
- Works with 20+ AI assistants via slash commands with no vendor lock-in
Developers and teams who want predictable AI output by agreeing on a proposal and spec before implementation, without adopting a heavyweight process.
Throwaway prototypes where writing a proposal is overhead. Compare with GitHub's Spec Kit (more structured phase gates, Python-based CLI) or Kiro (IDE-bound spec workflow).
Free and open-source under MIT; install with `npm install -g @fission-ai/openspec@latest` (Node.js 20.19+). You pay only for the AI coding assistant you already use.
The most widely adopted lightweight SDD framework for coding agents; a pragmatic middle ground between ad-hoc prompting and heavyweight spec toolkits.
Is OpenSpec free?
Yes - OpenSpec is Open Source. Free and open-source under MIT; install with `npm install -g @fission-ai/openspec@latest` (Node.js 20.19+). You pay only for the AI coding assistant you already use.
Is OpenSpec open source?
Yes - OpenSpec is open source. Free and open-source under MIT; install with `npm install -g @fission-ai/openspec@latest` (Node.js 20.19+). You pay only for the AI coding assistant you already use.
Who is OpenSpec best for?
Developers and teams who want predictable AI output by agreeing on a proposal and spec before implementation, without adopting a heavyweight process.
Who is OpenSpec not ideal for?
Throwaway prototypes where writing a proposal is overhead. Compare with GitHub's Spec Kit (more structured phase gates, Python-based CLI) or Kiro (IDE-bound spec workflow).
What are the best OpenSpec alternatives?
The closest OpenSpec alternatives on ai.dosa.dev are Pieces for Developers, agenttrace, Vibe Kanban - all listed under Developer Productivity & Workflow.
Who makes OpenSpec?
OpenSpec is developed by Fission-AI. It is listed in the Developer Productivity & Workflow category on ai.dosa.dev.
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