How to use these
Unzip, then work lab by lab in order — each one assumes the OpenSpec directory the previous lab created.
Start from starter/ and read that lab's README.md; only open solution/
once you have your own answer, because comparing two answers teaches more than reading one.
You need the OpenSpec CLI and an AI coding assistant. The labs were written against Claude Code, but the workflow is assistant-agnostic:
npx openspec@latest init --tools claude npx openspec@latest validate
OpenSpec Labs — Python
The main track. Nine labs from initialising OpenSpec in a repo through spec authoring, change proposals, implementation, team CI, security guardrails and a capstone.
OpenSpec Labs — Java
The same nine-lab arc on a Spring Boot service. Lab 06 is worth the trip on its own: a CI workflow that fails the build when a spec scenario has no matching test.
OpenSpec Labs — Data Engineering
Ten labs building a bronze / silver / gold pipeline specified before it is built, with data-quality expectations as acceptance criteria and a handoff capstone. Runs locally — no cloud account needed.