Skip to content

Jev directory

Reasoning Router

A router that asks a classifier, Jev by default, how much reasoning each step of a coding session needs, then adds that effort to the model request without breaking the prompt cache. It ships as an OpenCode plugin, a Pi extension and a local proxy for Codex CLI.
Stars
3
Language
TypeScript
License
MIT
Reading time
3 min
Published by
Community
Author
robertn702
Last verified
Oct 2026
Languages
TypeScript
Platforms
CLIAPI
Capabilities
Open sourceRequires API key

Highlights

  • Jev is the default classifier: it reads bounded excerpts of the recent conversation and picks an effort, low for a rename and high for a failing test.
  • The effort reaches the request as an OpenAI configuration_update item or an Anthropic effort-only system message, so the prompt prefix stays cacheable.
  • On SWE-bench Verified with GPT-6 Astra, a short Flask fix used 52% fewer output tokens and about half the time; harder issues saved only 5-7%.
  • Classifiers include Jev, Cloudflare Clef, Laya, Kev, OpenAI Decisions, CLM, Microsoft-Decision-1, Liquid d1 and SGLang, all chosen by configuration.
  • If the classifier is slow or unavailable the request still runs at the fallback effort, high by default; prompts and tool output are never logged.

Quickstart

bash
REASONING_ROUTER_CLASSIFIER=jev REASONING_ROUTER_CLASSIFIER_API_KEY=<typesafe-key> reasoning-router

Watch out

README reviewed 2026-10-17; the project is alpha, its SWE-bench numbers come from a few selected tasks that the README itself calls examples rather than an expected saving, and only specific model IDs and harness versions are tested.

Questions about this entry

Short answers drawn from the linked project or page.

Reactions & coverage

Posts, threads, and videos about this entry from around the web.

Facebook: Intake Router keeps diagnosis out of the answer space at the front desk.

FacebookClinicnotes

X: OpenRouter Decision Model Rankings

X: herdr + jev, an agent router

X: A group chat bot with decision room routing

From the Jev guides

Original write-ups on what this entry is for.

From the Jev AI model community

Posts from builders shipping with Jev right now.

Follow @typesafeai