OpenSpec puts a written spec between a request and the code an AI coding assistant writes, so the person and the assistant agree on what to build before implementation starts. Requirements otherwise live only in chat history, and OpenSpec moves them into plain Markdown files kept in the repository, with requirements stated as concrete WHEN and THEN scenarios and no special syntax.
Each change gets its own folder holding a proposal (why and what is changing), spec deltas (requirements and scenarios), a design (the technical approach), and a task checklist. The assistant drafts these from slash commands: explore to think through a problem against the codebase, propose to create the change folder, apply to implement the tasks, verify to check the implementation against the spec, and archive to merge the finished change into the project's living specs. Any artifact can be edited at any point, with no fixed phase gates, and the workflow is built for existing codebases as well as new ones.
The commands install into more than 30 coding assistants, including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode, Cline, Continue, Kilo Code, and Qwen Code, with the invocation form adapted to each tool. Stores, in beta, keep specs and changes in a separate repository shared across a team, so one change can plan a feature that spans several code repositories and a platform team can own requirements that product teams read. OpenSpec positions itself against Spec Kit as lighter with fewer phase gates, and against Kiro as independent of any one IDE or model family.
Features
- Change folders: each change holds a proposal, spec deltas, a design, and a task checklist
- Markdown specs: requirements written as plain Markdown with WHEN and THEN scenarios
- Explore command: reads the codebase, weighs options, and shapes a plan before any change is created
- Propose, apply, archive: draft a change, implement its tasks, and merge it into the living specs once done
- Verify command: checks that the implementation matches the spec
- Expanded profile: optional commands to step through artifacts one at a time, fast-forward, bulk-archive, and onboard
- Fluid editing: update any artifact at any time, with no rigid phase gates
- Tool support: slash commands and skills for 30+ coding assistants, with per-tool invocation syntax
- Stores (beta): a shared planning repository for cross-repo features and team-owned requirements
- Community schemas: third-party schema bundles that define opinionated workflows and tool integrations
