Lelantos

Lelantos provider for ComputeSDK — execute code in secure, EU-native Firecracker microVM sandboxes. Lelantos is an E2B-API-compatible platform running on Hetzner bare-metal in the EU, so this provider wraps the same e2b npm SDK pointed at the Lelantos control plane.

Installation & Setup

npm install @computesdk/lelantos

Add your Lelantos credentials to a .env file:

LELANTOS_API_KEY=lel_your_api_key_here
# Optional — override the control-plane + sandbox domain (defaults to lelantos.ai)
LELANTOS_DOMAIN=lelantos.ai
# Optional — explicit control-plane URL (overrides the domain-derived URL)
LELANTOS_API_URL=https://api.lelantos.ai

Lelantos issues lel_… keys. The provider accepts both the lel_… and e2b_… forms of a Lelantos key, and resolves credentials with the fallback order config → LELANTOS_* → E2B_* so it is a drop-in for E2B-shaped configs.

Usage

import { lelantos } from '@computesdk/lelantos';

const compute = lelantos({
  apiKey: process.env.LELANTOS_API_KEY,
});

// Create sandbox
const sandbox = await compute.sandbox.create();

// Run a command
const result = await sandbox.runCommand('echo "Hello from Lelantos!"');
console.log(result.stdout); // "Hello from Lelantos!"

// Clean up
await sandbox.destroy();

Configuration Options

interface LelantosConfig {
  /**
   * Lelantos API key. Accepts the `lel_…` form OR the `e2b_…` form of a
   * lelantos key (a native `lel_<hex>` key is transparently presented to the
   * e2b SDK as its `e2b_<hex>` alias). If not provided, falls back to the
   * `LELANTOS_API_KEY` environment variable, then `E2B_API_KEY`.
   */
  apiKey?: string;
  /**
   * Lelantos control-plane + sandbox domain, e.g. `'lelantos.ai'`. The e2b SDK
   * derives the control-plane URL as `https://api.${domain}` and the sandbox
   * preview host as `{port}-{sandboxId}.${domain}`. If not provided, falls back
   * to the `LELANTOS_DOMAIN` then `E2B_DOMAIN` environment variable, then
   * defaults to `'lelantos.ai'`.
   */
  domain?: string;
  /**
   * Explicit control-plane URL override (e.g. a non-`api.` host or a port).
   * Takes precedence over `domain`-derived URLs for control-plane calls. Falls
   * back to `LELANTOS_API_URL` then `E2B_API_URL`.
   */
  apiUrl?: string;
  /** Execution timeout in milliseconds (defaults to 300000). */
  timeout?: number;
}

Supported Operations

Method	Supported	Notes
create	✅	Boot from a templateId / snapshotId when supplied.
getById	✅	Reconnects to a running sandbox by id.
list	✅
destroy	✅
runCommand	✅	Supports env, cwd, background. Real non-zero exit codes are returned, not thrown. Transient infra errors are retried with backoff.
getInfo	✅
getUrl	✅	Returns https://{port}-{sandboxId}.{domain} for the given port.
filesystem	✅	readFile, writeFile, mkdir, readdir, exists, remove (native e2b files).
snapshot	✅	compute.snapshot.create snapshots a running sandbox; list / delete map to templates.
template	partial	list / delete supported; create throws — build via the E2B template protocol / CLI or snapshot.create().

Notes

• Because the wire protocol is E2B-compatible, domain / apiUrl are threaded into every SDK call (create, connect, list, kill, snapshot, template) so lifecycle operations stay on Lelantos rather than falling back to api.e2b.app.
• Sandboxes run in the EU (single-region today).
• Point at a self-hosted or staging slot by setting domain (and optionally apiUrl).