Execute JavaScript inside a hardened V8 isolate (isolated-vm) and return everything it printed.

Each call gets a brand new isolate, so no state, memory or globals are shared between runs. The isolate is a separate heap with no access to the host process: there is no require, process, timer or file-system API available.

Limits, per call:

• 512 MB of V8 heap.

• 30 seconds of wall time; the isolate is disposed when the limit is hit.

fetch is available: the isolate has no network stack of its own, so each request is performed by the host process and the response is copied back in. Per request:

• 10 seconds of wall time; a slower request rejects with a TimeoutError.

• Bodies in either direction are capped at 8388608 bytes.

• http: and https: URLs only; the host sends no cookies and follows redirects unless redirect says otherwise.

Language notes:

• The first line of the response reports how long the run took.

• The snippet runs as the body of an async function, so top-level await and top-level return are both allowed.

• console.log/console.info/console.debug are captured as stdout; console.warn, console.error and console.trace are captured as stderr.

• fetch, Headers, Response, AbortController, TextEncoder and TextDecoder are minimal shims: response.text(), response.json(), response.arrayBuffer() and response.clone() work, but response.body is null (no streams, no blob()), URL/Request/FormData/Blob do not exist, and the isolate has no timers, so setTimeout and AbortSignal.timeout are unavailable.

• A top-level return value is reported back under result:. - Uncaught exceptions, syntax errors and their stack traces are reported back under error:, and the tool is flagged as an error.

Execute TypeScript inside a hardened V8 isolate (isolated-vm) and return everything it printed.

Each call gets a brand new isolate, so no state, memory or globals are shared between runs. The isolate is a separate heap with no access to the host process: there is no require, process, timer or file-system API available.

Limits, per call:

• 512 MB of V8 heap.

• 30 seconds of wall time; the isolate is disposed when the limit is hit.

fetch is available: the isolate has no network stack of its own, so each request is performed by the host process and the response is copied back in. Per request:

• 10 seconds of wall time; a slower request rejects with a TimeoutError.

• Bodies in either direction are capped at 8388608 bytes.

• http: and https: URLs only; the host sends no cookies and follows redirects unless redirect says otherwise.

Language notes:

• The first line of the response reports how long the run took.

• The snippet is compiled with esbuild (types stripped) and then executed exactly like run_javascript: same isolate, same limits, same output capture.

• import/export module syntax is not supported: the isolate has no module resolver, so the snippet has to be self-contained.

• Constructs that emit new code (enum, namespace, constructor parameter properties) make esbuild produce extra lines, so a runtime stack trace can point past the line you wrote. Plain type annotations keep line numbers exact.

• The snippet runs as the body of an async function, so top-level await and top-level return are both allowed.

• console.log/console.info/console.debug are captured as stdout; console.warn, console.error and console.trace are captured as stderr.

• fetch, Headers, Response, AbortController, TextEncoder and TextDecoder are minimal shims: response.text(), response.json(), response.arrayBuffer() and response.clone() work, but response.body is null (no streams, no blob()), URL/Request/FormData/Blob do not exist, and the isolate has no timers, so setTimeout and AbortSignal.timeout are unavailable.

• A top-level return value is reported back under result:. - Uncaught exceptions, syntax errors and their stack traces are reported back under error:, and the tool is flagged as an error.