Build it once.
Never again.

hammerkit runs your build in containers, on your laptop and in CI alike, and skips every task whose inputs didn’t change — wherever it ran first.

Get startednpm install --global hammerkit

Same tools everywhere

Every task runs in the image it names. No “works on my machine”.

Skips what didn’t change

A task reruns only when a file it reads changes — locally and in CI.

Shared across machines

Laptops, CI runners and agent sandboxes reuse each other’s results.

Agent-ready

Hand your coding agent the migration guide and it rewrites your CI.

Where do you want to start?

I’m new to hammerkit

I want to optimize my CI

I build with coding agents

One file for every machine

Tasks declare their image, what they read and what they produce.

.hammerkit.yaml

tasks:  install:    image: node:24-alpine    src: [package.json, package-lock.json]    generates: [node_modules]    cmds: [npm ci]  test:    image: node:24-alpine    deps: [install]    needs: [db]    src: [src, test]    cmds: [npm test]  build:    image: node:24-alpine    deps: [install]    src: [src, tsconfig.json]    generates: [dist]    cmds: [npm run build]

…and CI shrinks to this

The same command your laptop runs. Cache hits execute nothing.

.github/workflows/ci.yml

steps:  - uses: actions/checkout@v4  - uses: no0dles/hammerkit-github-action@v1  - run: hammerkit run ci

Let an agent migrate your CI →

Build it once.Never again.