First sandbox: JS/TS - sandkiln

npm install sandkiln

import { Sandbox } from "sandkiln";

const sandbox = await Sandbox.create({ tags: { env: "demo" } });
console.log("created:", sandbox.id);
// created: 1fa417db-10af-4e77-97a0-8d26347f13e2

const result = await sandbox.runCommand("python3", ["-c", "print(21 * 2)"]);
console.log(result.stdout.trim(), result.exitCode);
// 42 0

await sandbox.stop(); // preserved as a resumable snapshot by default

Sandbox.create(), list(), and every instance method reuse the baseUrl/authToken you pass in, or fall back to the SANDKILN_DAEMON_URL/SANDKILN_AUTH_TOKEN environment variables — see Auth.

A failed command doesn’t reject the promise

runCommand reports whatever the command actually did — exit code and stderr included — it doesn’t throw just because the exit code was non-zero. Check result.exitCode the same way a shell script checks $?:

const failed = await sandbox.runCommand("cat", ["/does/not/exist"]);
console.log("exit code:", failed.exitCode, "stderr:", failed.stderr.trim());
// exit code: 1 stderr: cat: /does/not/exist: No such file or directory

SandkilnApiError is reserved for the request itself failing — a bad sandbox id, an unreachable daemon, a validation error. Calling any method after stop() (without resume()-ing it first) is the everyday way to see one:

import { SandkilnApiError } from "sandkiln";

try {
  await sandbox.runCommand("echo", ["hi"]);
} catch (err) {
  if (err instanceof SandkilnApiError) {
    console.log(err.message);
    // sandbox not found: 1fa417db-10af-4e77-97a0-8d26347f13e2
  }
}

Next

Give the sandbox a name so you can find it again later: Named sandboxes & persistent stop.
Boot from your own image instead of the daemon’s default: Boot from a custom image.
Full method reference: JS/TS SDK.