playground

name	playground
description	Use a sandboxed JavaScript worker to execute small snippets for calculation, data shaping, and behavior verification.

Playground Tool

playground lets the assistant run JavaScript module code in an isolated web-worker sandbox.

When to use

• Quick calculations that are easier to validate with code
• Data transformation checks (map/filter/reduce/grouping)
• Small logic experiments before writing production code

Input contract

The tool expects:

• code (required): JavaScript module source code
• args (optional): array of arguments passed to default export
• timeoutMs (optional): execution timeout, default is 2000
• whiteList (optional): allowed global APIs inside sandbox

The runtime also injects a global helper:

• getFile(index) (1-based): get uploaded file payload from the current session history

getFile(index) returns:

• index: file index (starts from 1)
• name: original filename
• type: MIME type
• size: file size (bytes)
• lastModified: file timestamp
• text: file text content

code must export a default function:

export default function main(input) {
  return { ok: true, size: Array.isArray(input) ? input.length : 0 };
}

Example call

{
  "name": "playground",
  "params": {
    "code": "export default function () { const file = getFile(1); return { fileName: file?.name ?? null, first20: file?.text?.slice(0, 20) ?? null }; }"
  }
}

Output

• success: true with result when execution succeeds
• success: false with error when parsing/execution/timeout fails

Notes

• Keep snippets small and deterministic
• Avoid depending on blocked globals (network, timers, DOM, dynamic eval)
• Use getFile(index) when you need to parse or inspect user-uploaded files