OpenSpec writes every change as a delta against your current specs. You learn the full loop in Claude Code: propose, review, apply, verify, archive. Then you adopt it on a mature repo.
A /health endpoint shipped end-to-end through propose, apply and archive
An openspec/config.yaml with a real project description and per-artifact rules
A pre-commit hook that runs openspec validate --strict
A saved filter views feature on an existing orders app, including a mid-change pivot, verify, archive and one PR with the full artifact trail
Why OpenSpec exists, what 'brownfield-first' actually means in practice, the delta-spec model, the five stated principles, and when OpenSpec is the wrong tool.
Install @fission-ai/openspec, run openspec init with Claude Code auto-detected, and ship a tiny change end-to-end with the propose workflow.
Tour the four files OpenSpec generates — proposal.md, design.md, tasks.md, specs/*.md — and learn how reviewers read them as a coherent change package.
Write requirements that pass openspec validate --strict — RFC 2119 keywords, 4-hashtag scenarios, ADDED/MODIFIED/REMOVED/RENAMED deltas, and the hidden-requirement detector.
Walk a real change end-to-end with Claude Code: propose → review → apply → verify → archive. Includes bulk-archive, openspec check, and project-scoped profile resolution.
Master the v1.2+ profile system (core vs custom), openspec/config.yaml, per-artifact rules, and project context optimization — the levers that adapt OpenSpec to your stack.
Head-to-head comparison: OpenSpec, BMAD, GitHub Spec Kit, Amazon Kiro, Spec Workflow MCP, and a raw .tasks/ pattern. Dimensions, trade-offs, and a decision tree for picking the right one.
Use OpenSpec from Claude Code, Cursor, Codex, Windsurf, Gemini CLI, GitHub Copilot, and others — switching tools mid-change without losing the spec trail.
Add OpenSpec to a 5-year-old codebase without rewriting history — onboarding playbook, project context priming, and the most common pitfalls.
Apply everything: propose a real feature, walk the full workflow with Claude Code, customize a profile mid-change, verify, archive, and produce a reviewable artifact trail.
One year of access for $20, or subscribe for $45/month to get this course and every other one.
Node.js 18+, Claude Code installed and signed in, and a project with at least one source file. A scratch repo works. OpenSpec needs no API keys and no MCP server. Other agents work too; one tutorial covers Cursor, Codex, Windsurf and Gemini CLI.
The course has 10 tutorials. The listed lesson times add up to about 5.5 to 7 hours. The first install tutorial ships a one-line change in about 20 minutes.
No. That course teaches spec-first foundations and BMAD. This one is OpenSpec: lightweight, delta-based, built for brownfield code. One tutorial compares the two head to head and covers when to run both side by side.
Yes, that is the main use case. You init in brownfield mode, so specs/ starts empty. You write project context once, then add specs one domain at a time as you change code. The brownfield tutorial covers the pitfalls.