Install

Each install writes a Jupyter kernelspec: cdp-node, cdp-deno, cdp-node-deno (Node with the Deno compatibility namespace), cdp-bun, cdp-workerd, or cdp-celld. Then pick the kernel in JupyterLab or VS Code.

From npm

The host runs on Node 24+. CI tests Node 24 and 26 with Deno 2.9 and the latest 2.x, on Linux and macOS. Windows isn't supported yet.

npm install -g @tlockney/cdp-kernel
cdp-kernel install --runtime node
cdp-kernel install --runtime deno
cdp-kernel install --runtime node --deno-compat
cdp-kernel install --runtime bun
cdp-kernel install --runtime workerd
cdp-kernel install --runtime celld

The kernelspec records the absolute paths of node and the installed package. Re-run install after upgrading either.

From JSR

The host runs on Deno:

deno run -A jsr:@tlockney/cdp-kernel/cli install --runtime deno

The kernelspec pins the release it was installed from (jsr:@tlockney/cdp-kernel@<version>/cli). On first launch the target's runtime modules are copied into ~/.cache/cdp-kernel/runtime/.

Release day on Deno

Deno 2.9+ refuses package versions less than 24 hours old by default (minimum dependency age). In a release's first day, the install command fails with "blocked by the minimum dependency age policy". Pass --min-dep-age=0 to the install command to get it through:

deno run -A --min-dep-age=0 jsr:@tlockney/cdp-kernel/cli install --runtime deno

The kernelspec it writes works on release day too. It relaunches the kernel with a dependency cutoff of two days after the release (--min-dep-age=<date>), so it never resolves anything published after that.

Target runtimes

Whichever way the host is installed, the target runtime must be present. A Node target needs node on PATH, and a Bun target needs bun (1.4 is what's been tested). A workerd target uses the workerd in the notebook directory's node_modules (a Workers project has one through wrangler), or the one on PATH (npm install -g workerd; 2026-10-15 is what's been tested). A celld target uses ~/.local/bin/celld, where celld's installer puts it, or the one on PATH (0.6.2 is what's been tested; celld has no Windows build).

From a checkout

For working on the kernel itself:

npm ci
npm run install:node        # kernelspec cdp-node
npm run install:deno        # kernelspec cdp-deno
npm run install:node-deno   # kernelspec cdp-node-deno
npm run install:bun         # kernelspec cdp-bun
npm run install:workerd     # kernelspec cdp-workerd
npm run install:celld       # kernelspec cdp-celld

These kernelspecs point at the checkout, so don't move it after installing.