[AadarshM07]

Description

Code mode enables an LLM to submit a multi-step JavaScript script that chains and filters tool calls in an isolated sandbox, executing in a single model round trip rather than individual network hops.

Key Changes

1. Synthetic Tools Catalog (synthetic_tools.py, transform.py):

   • Exposes search, get_schema, and execute (configurable names).
   • Replaces the exposed MCP tools catalog while preserving pipeline execution for internal real tool calls.

2. Isolated Worker Pool (worker_pool.py, guest_evaluator.py):

   • Manages a pool of isolated worker subprocesses using multiprocessing.get_context("spawn").
   • Uses embedded quickjs with memory caps (memory_limit_mb) and evaluation timeouts.
   • Recycles dead or timed-out worker slots to keep serving subsequent requests seamlessly.

3. Destructive Guard (destructive_guard.py):

   • Treats a tool as destructive unless readOnlyHint: true or destructiveHint: false.
   • Blocks destructive tool execution inside code scripts unless allow_destructive: true is explicitly configured.

4. Legible Errors (legible_error.py):

   • Formats evaluation errors with line locations while scrubbing host file paths and internal Python stack traces.

5. Optional Dependency (pyproject.toml):

   • Packaged under nitrostack[code-mode].
   • Base import nitrostack continues to function without the extra installed.

6. Type Safety:

   • Uses multiprocessing.process.BaseProcess to support context-specific SpawnProcess.
   • Safely guards awaitable tool results using inspect.isawaitable.

closes #66

[manish-wekan]

Lets apply the script timeout while a tool call is in progress too: a slow tool ran 513 ms past a 50 ms limit.

Revert the unrelated uv.lock revision downgrade (5 → 3). Remove the blank line at the end of the file.

~sent from claude-code