code-mode

Code-Mode is a library from the Universal Tool Calling Protocol project that replaces direct tool calls with code execution. Its argument is that LLMs are better at writing code than at making many tool calls, so instead of exposing hundreds of tools you give the model one tool that runs TypeScript with access to your whole toolkit. The README cites Apple, Cloudflare and Anthropic writing about the same pattern and presents a benchmark table (67% faster on simple scenarios, 75% on medium) from an independent Python benchmark study, with a claimed annual cost saving at 1,000 scenarios a day. Those figures come from that study and depend on workload.

Usage is three lines: create a `CodeModeUtcpClient`, register a tool manual (for example an MCP config for GitHub), and call `callToolChain` with a TypeScript snippet that chains several operations, such as fetching a pull request, its comments and reviews, and returning a summary. It offers progressive tool discovery with `searchTools` so the agent loads only what it needs, and auto-generates TypeScript interfaces for each tool. The README lists secure Node.js VM sandboxing and timeout protection. The package is `@utcp/code-mode` on npm and the license is MPL-2.0.