Interactive JavaScript REPL

Deno Sandbox provides a sandboxed Linux microVM. This is useful for evaluating code that is not trusted or for testing code that is not safe to run in your main runtime.

A REPL (Read–Eval–Print Loop) is an interactive execution session where you type code, the environment reads it, evaluates it, prints the result, and then keeps the session alive so you can continue running more code while preserving state.

The repl() method can be used to provide an interactive JavaScript REPL in a sandbox.

import { Sandbox } from "@deno/sandbox";

await using sandbox = await Sandbox.create();

// Start a Deno REPL
const repl = await sandbox.deno.repl();

// Execute code interactively, maintaining state
await repl.eval("const x = 42;");
await repl.eval("const y = 8;");
const result = await repl.eval("x + y");
console.log("result:", result); // 50

For more information, see the Deno Sandbox documentation.