Jev Router
A local router chooses a model tier for each Claude Code or Codex turn.
Added to Jevfast
How it uses Jev
Jev receives the fresh prompt, current model and context token count, and available model IDs. It scores complexity dimensions and chooses an exact model ID; routing policy applies confidence and context rules before the CLI starts the turn.
What Jev decides
Illustrative Jev decisionExample answers · not a recorded Jev response · Source ↗
Question 1 · model
YOUR APP
INSTRUCTION
Choose the cheapest exact available model that can complete the request in one pass.
STATE
New request text, current model and context tokens, with the default Haiku, Sonnet, and Opus model IDs available.
JEV · CHOICE
- claude-haiku-4-5-20251001
- claude-sonnet-5
- claude-opus-5
Question 2 · task complexity
YOUR APP
INSTRUCTION
Score overall task complexity including ambiguity, scope, and blast radius.
STATE
New request text, current model and context tokens, with the default Haiku, Sonnet, and Opus model IDs available.
JEV · SCORE
0
App workflow
- Inspect turn
Read prompt, current model, context size, and available model tiers.
- Ask Jev
Request complexity Scores and a model Choice in one call.
- Apply routing policy
Use confidence, overrides, context size, and available tiers to settle on a model.
- Launch CLI turn
Pass the selected model through the existing CLI interface.
Why it is interesting
It routes only fresh turns while preserving native CLI behavior, and explicitly accounts for the prompt-cache cost of switching models.