@openexam/runtime-wasi

WASM-sandboxed runtimes for student-code execution (per ADR-005). The host instantiates a Runtime for the desired language and calls runtime.run({ source, stdin, fuelMs }); output is captured per RuntimeResult.

v1 ships JavaScript via QuickJS-WASM. Pyodide for Python is a follow-on against the same Runtime interface.

import { javascriptRuntime } from '@openexam/runtime-wasi';

const js = javascriptRuntime();
const result = await js.run({
  source: `console.log(1 + 2)`,
  fuelMs: 1000,
});
// result.stdout === '3\n'
// result.exitCode === 0

The runtime injects a small student-facing API:

• console.log(...args) — comma-joined output to stdout.
• print(...args) — alias for console.log.
• readline() — returns the next line of stdin, or null at EOF.

Determinism guarantees per ADR-005: no clock, no RNG (the host's seeded RNG isn't exposed in the student runtime), no network, no filesystem. The fuel limit (fuelMs, default 2000 ms) is enforced via QuickJS's interrupt handler.

License

Apache-2.0. See LICENSE and the canonical ../../LICENSE at the repository root.