Cavekit
Cavekit is a Claude Code plugin for spec-driven development. It keeps one durable SPEC.md at the repo root, encodes it in caveman grammar to keep it cheap to reread, and folds test failures back into the spec instead of leaving them for you to reconcile by hand.
Cavekit is a separate, standalone project — JuliusBrussee/cavekit on GitHub, MIT licensed. It is not a package in this repository.
Why a single file
Most spec-driven workflows lose the spec the moment the context resets — sub-agents scatter it, dashboards move it out of the repo, and the next session starts from scratch. Cavekit keeps SPEC.md in the repo root instead, so it survives resets the same way any other tracked file does. It is written in caveman grammar rather than prose, which keeps it roughly ~75% cheaper to reread than an equivalent prose spec — an approximate figure, not a guarantee for any given spec.
Right-size, not ceremony-by-default
Cavekit's stated principle is that ceremony should match the size of the change. A one-line fix does not need the same spec weight as a new subsystem. There are no sub-agents, no dashboards, and no orchestration layer sitting on top of the loop.
The loop
Three commands carry a change from spec to a passing build:
| Command | What it does |
|---|---|
/ck:spec | create, amend, or backpropagate SPEC.md |
/ck:build | plan and execute against the spec, auto-backpropagating on test failure |
/ck:check | read-only drift report between spec and code |
/ck:spec # write or update SPEC.md
/ck:build # implement against it; failures feed back into invariants
/ck:check # confirm code and spec still agreeReach-for commands
Four more commands cover the edges of the loop — sharpening an idea before it becomes a spec, gathering outside knowledge, reviewing a spec adversarially before you build against it, and going deep on one module:
| Command | What it does |
|---|---|
/ck:grill | sharpen a fuzzy idea into a spec-ready shape |
/ck:research | gather sourced external knowledge into the spec |
/ck:review | adversarial pre-build review of a spec |
/ck:deepen | a focused design pass on one module |
Install
npx skills add JuliusBrussee/cavekitOr through the Claude Code plugin marketplace:
/plugin marketplace add juliusbrussee/cavekit
/plugin install ck@cavekit