OpenSpec 1.13.0 adds an explore command in front of propose, so brownfield codebases get current-behavior discovery before any planning artifact is written
OpenSpec (Fission-AI, MIT) is a spec layer that works across Claude Code, Cursor, Codex, Copilot and 50+ other agents via five slash commands: /opsx:explore, /opsx:propose, /opsx:apply, /opsx:verify, /opsx:archive. Propose emits proposal.md, a specs/ directory, design.md and tasks.md; apply executes the tasks; verify checks the implementation against the spec; archive moves the completed change to history. The design point worth stealing is explore as a distinct no-stakes phase that reads existing code and shapes a plan before any artifact is committed, which is aimed squarely at brownfield adoption where the agent's first failure is assuming behavior it never read. The project hit the HN front page at 154 points on 16 September.
↳ Follow the thread