@silviomollov/ai-isolate-quickjs

Temporary fork of @tanstack/ai-isolate-quickjs 0.1.45 (MIT, © TanStack). Host tool functions are bridged as QuickJS promises instead of asyncify suspensions, fixing refcount corruption / WASM aborts on sequential awaits of the same tool binding (quickjs-emscripten#258), and enabling concurrent tool calls via Promise.all. The fix uses the plain (non-asyncify) QuickJS build — if you bundle the wasm yourself, ship @jitl/quickjs-wasmfile-release-sync/wasm. This package will be deprecated once the fix lands upstream.

Drop-in usage via npm alias: "@tanstack/ai-isolate-quickjs": "npm:@silviomollov/[email protected]"

QuickJS WASM driver for TanStack AI Code Mode. Runs everywhere — Node.js, browsers, and edge runtimes — with zero native dependencies.

Installation

pnpm add @tanstack/ai-isolate-quickjs

Usage

import { createQuickJSIsolateDriver } from "@tanstack/ai-isolate-quickjs";
import { createCodeModeTool } from "@tanstack/ai-code-mode";

const driver = createQuickJSIsolateDriver({
  timeout: 30000, // execution timeout in ms (default: 30000)
  memoryLimit: 128, // memory limit in MB (default: 128)
  maxStackSize: 512 * 1024, // max stack size in bytes (default: 512 KiB)
});

const executeTypescript = createCodeModeTool({
  driver,
  tools: [myTool],
});

Config Options

• timeout — Default execution timeout in milliseconds (default: 30000)
• memoryLimit — Default QuickJS runtime memory limit in MB (default: 128)
• maxStackSize — Default QuickJS runtime max stack size in bytes (default: 524288)

Tradeoffs vs Node Driver

| | QuickJS (WASM) | Node (isolated-vm) | | --------------- | -------------------------- | ----------------------- | | Native deps | None | Yes (C++ addon) | | Browser support | Yes | No | | Performance | Slower (interpreted) | Faster (V8 JIT) | | Memory limit | Configurable | Configurable | | Best for | Browser, edge, portability | Server-side performance |

How It Works

Uses QuickJS compiled to WebAssembly via quickjs-emscripten. Each execution creates a fresh async QuickJS context with tool bindings injected as global async functions.

Runtime Limits and Errors

• QuickJS enforces runtime memory and stack limits for each context.
• Exceeding limits can produce normalized errors such as MemoryLimitError or StackOverflowError.
• Certain fatal limit conditions may dispose the underlying VM; create a fresh context before running more code after disposal.

Refreshing the Fork

From Git Bash, refresh the staged sources and set the next package version with:

./refresh.sh 0.1.46-fork.2

The source repository defaults to the sibling ../ai directory. Set REPO_DIR if it is elsewhere.

License

MIT