Node.js daemon server for running isolated-vm runtimes via IPC
npm install @ricsam/isolate-daemonNode.js daemon server that manages isolated-vm runtimes via Unix socket or TCP. Allows non-Node.js runtimes (Bun, Deno, etc.) to use isolated-vm through IPC.
``bash`
npm add @ricsam/isolate-daemon
- Unix domain socket and TCP transport
- Multiple concurrent connections
- Runtime lifecycle management (create, dispose)
- Bidirectional callback bridging (console, fetch, fs)
- Test environment support (enabled via testEnvironment: true)
- Playwright integration (client owns the browser, daemon invokes callbacks)
- Connection-scoped resource cleanup
- Namespace-based runtime pooling with LRU eviction for performance optimization
`typescript
import { startDaemon } from "@ricsam/isolate-daemon";
const daemon = await startDaemon({
socketPath: "/tmp/isolate-daemon.sock", // Unix socket
// Or TCP: host: "127.0.0.1", port: 47891
maxIsolates: 100,
defaultMemoryLimitMB: 128,
});
console.log(Daemon listening on ${daemon.address});
// Get stats
const stats = daemon.getStats();
console.log(Active isolates: ${stats.activeIsolates});
// Graceful shutdown
await daemon.close();
`
`bashStart daemon on default socket
npx isolate-daemon
Options
typescript
interface DaemonOptions {
socketPath?: string; // Unix socket path
host?: string; // TCP host
port?: number; // TCP port
maxIsolates?: number; // Maximum concurrent isolates
defaultMemoryLimitMB?: number; // Default memory limit in megabytes
}
`Statistics
typescript
interface DaemonStats {
activeIsolates: number;
activeConnections: number;
totalIsolatesCreated: number;
totalRequestsProcessed: number;
}
`Runtime Pooling with Namespaces
The daemon supports namespace-based runtime pooling for improved performance. When a client creates a runtime with a namespace ID, the runtime is cached on dispose (soft-delete) rather than destroyed. Future requests with the same namespace ID reuse the cached runtime, preserving:
- V8 Isolate instance
- V8 Context
- Compiled ES module cache
- Global state and imported modules
$3
1. Client creates a namespace:
2. Client creates a runtime in that namespace:
3. On dispose, runtime is soft-deleted (cached in pool)
4. Any client can later request the same namespace and reuse the cached runtime
5. When limit is reached, oldest disposed runtimes are evicted (LRU)$3
- Non-namespaced runtimes (
client.createRuntime()) work as before - true disposal on dispose
- Namespaced runtimes are cached and reusable across connections
- LRU eviction removes oldest disposed runtimes when at capacity
- Connection close soft-deletes namespaced runtimes (keeps them in pool)
- Concurrent createRuntime calls for the same namespace are rejected with Namespace "The
MIT