tspice

Node (native backend) ​

In Node, you can choose between:

  • Native backend (backend: "node"): fastest, uses a native addon
  • WASM backend (backend: "wasm"): portable, no native build
ts
import { spiceClients } from "@rybosome/tspice";

const { spice, dispose } = await spiceClients.toSync({ backend: "node" });

try {
  console.log(spice.raw.tkvrsn("TOOLKIT"));
} finally {
  await dispose();
}

If you see errors about missing native bindings, see the backend package docs:

  • @rybosome/tspice-backend-node

For a broader error catalog (native addon resolution, wasm fallback, kernel preload/fetch issues), see /guide/troubleshooting.

Loading kernels from the filesystem ​

With the native backend, kernels can be loaded directly from absolute filesystem paths (no URL hosting required):

ts
import { spiceClients } from "@rybosome/tspice";

const { spice, dispose } = await spiceClients.toSync({ backend: "node" });

try {
  spice.kit.loadKernel("/abs/path/to/naif0012.tls");
  // Or the low-level equivalent:
  spice.raw.furnsh("/abs/path/to/pck00011.tpc");
} finally {
  await dispose();
}

Kernel preloading via .withKernels(pack) fetches bytes via fetch, so it’s best when kernels are hosted at URLs.

WASM backend ​

If you don’t want native addons, the WASM backend works in Node too:

ts
import { spiceClients } from "@rybosome/tspice";

const { spice, dispose } = await spiceClients.toAsync({ backend: "wasm" });

try {
  console.log(await spice.kit.toolkitVersion());
} finally {
  await dispose();
}

Notes ​

  • @rybosome/tspice is ESM-only. In CommonJS, use await import("@rybosome/tspice").
  • Kernel preload via .withKernels(pack) fetches bytes via fetch (best for URL-hosted kernels). Node 18+ has fetch built in. In Node, fetch() requires absolute URLs (either use absolute kernel.url values, or set pack.baseUrl to an absolute URL like https://…/).