# Building a harness with Jev

LangChain on model routing and gating dangerous tool calls behind a typed decision.

- URL: https://www.langchain.com/blog/building-a-harness-with-jev
- Section: Articles and talks / Essays and threads
- Type: resource
- First seen: 2026-09-18

Page: https://awesomejev.vercel.app/p/building-a-harness-with-jev/