Filesystem

import { JavaScriptRuntime } from "@rivet-dev/agentos/javascript";

// Boot a fully virtualized VM. The guest filesystem lives entirely inside the
// kernel - writes never touch the host disk.
const rt = await JavaScriptRuntime.create();

try {
	// Guest code runs as an ES module inside the VM. It writes and reads files
	// using the standard node `fs` module, backed by the kernel's virtual
	// filesystem.
	const { stdout, stderr, exitCode } = await rt.execute(`
    import { mkdirSync, writeFileSync, readFileSync, readdirSync } from "node:fs";

    mkdirSync("/workspace", { recursive: true });
    writeFileSync("/workspace/hello.txt", "hello from the VM");

    const message = readFileSync("/workspace/hello.txt", "utf8");
    const entries = readdirSync("/workspace");

    console.log("read back from VM:", message);
    console.log("/workspace contents:", JSON.stringify(entries));
  `);

	console.log("exitCode:", exitCode);
	if (stderr.trim()) console.log("guest stderr:", stderr.trim());
	console.log("guest stdout:");
	console.log(stdout.trim());
} finally {
	await rt.dispose();
}