What it is
jcm-router is a local proxy between Claude Code and the Anthropic API for developers using a Claude subscription. It routes subagents and, when cheap, the main chat to different Claude models and effort levels.
How it uses Jev
For /v1/messages requests with tools and a real user message, the proxy sends Jev a state of user message, previous assistant reply, and previous routing. Jev answers model (choice), effort (choice), and is_followup (yes/no). Below confidence gates the original model or effort is kept.
Primitives:choicenoul
Technique worth stealing
Route subagents freely but guard main-chat switches, because prompt caches are per model and switching rewrites the cached prefix at cache-write price.
Try it
git clone, bun install, set TYPESAFE_API_KEY, bun run up, then point Claude Code at localhost:8787.
Evidence
Each line is one question put to Jev about the README. ≥ 0.60 reads as yes, ≤ 0.40 as no; in between Jev is not making a call.
- Jev-centricyes0.93
- Shows a System One patternyes0.69
- Handles uncertaintyno0.05
- Measuredno0.12
- Runnableyes0.94
- Worth recommendingunclear0.42
- Model replicano0.07
- Problem scopescore on a 0–2 scale1.04
- About Jevyes0.97
Signals by Jev jev-1.13.0, card written by DeepSeek V4.1 Flash from the README on 20 Sept 2026.