Show HN: Sandboxing untrusted code using WebAssembly

Re:Show HN: Sandboxing untrusted code using WebAssembly by mavdol04 on Tuesday February 03, 2026 @12:49PM (#46874359)

yeah, the previous example was quite basic. I will write a complete example for that, but here is how you can run dynamic code:

   import { task } from "@capsule-run/sdk";

   export default task({
     name: "main",
     compute: "HIGH",
   }, async () => {
     const untrustedCode = "const x = 10; x * 2 + 5;";
     const result = eval(untrustedCode);
     return result;
   });

Hope that helps!

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Re:Show HN: Sandboxing untrusted code using WebAssembly by zachrip on Thursday February 05, 2026 @08:16AM (#46899297)

Is the code in the eval also turned into wasm first then? Does this work as a JIT for wasm?

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Re:Show HN: Sandboxing untrusted code using WebAssembly by mavdol04 on Thursday February 05, 2026 @06:40PM (#46907046)

It actually works a bit differently. The eval is executed by the interpreter running inside the isolated wasm sandbox (StarlingMonkey). You can think of it as each sandbox having its own dedicated JavaScript engine.

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