Jev in production › Model and agent routing

Miser

Jev classifies prompt complexity to route requests in an open-source AI gateway; a held-out benchmark reports 89.7% exact accuracy versus 83.6% for its own heuristic fallback (Miser).

Open on GitHub ↗

89.7%measured against a baseline, as published by the source
Use
Model and agent routing
Industry
AI infrastructure
Form
Open-source tool
Stage
In production
Listed
2026-09-27
Found via
github
Repository
rShetty/miser
Stars
5
Forks
0
Last push
2026-09-28
Language
Rust
License
MIT

The README opens with

Miser is an open-source, Rust-based AI gateway that intelligently routes OpenAI-compatible requests to the optimal model through OpenRouter. Powered by Jev (TypeSafe's System One evaluation model), Miser delivers the best routing accuracy in the industry.

Miser uses Jev to classify every prompt into a complexity tier (trivial → simple → standard → hard → reasoning) and routes to the cheapest capable model. The results speak for themselves:

Held-out benchmark (116 adversarial cases in evals/classifiercases.jsonl, never used for tuning):

Badge

For the project's own README, linking back here:

Listed in Jev in production

Also used for model and agent routing