What it is
A small async LangGraph workflow that sends a mocked email to TypeSafe's Jev model, receives a typed Choice (invoice or general), and routes to a demo handler. Handlers only set a destination in graph state; they do not send email or make payments.
How it uses Jev
Jev detects intent from the email state, returning a Choice between invoice and general. The graph routes to the matching handler based on this Choice. Confidence and label probabilities are exposed for inspection, but the demo always routes to one of the two handlers.
Primitives:choice
Technique worth stealing
Use typed Choice to route emails in a LangGraph workflow.
Try it
uv sync; set TYPESAFE_API_KEY; uv run python main.py
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-centricyes0.95
- Shows a System One patternno0.35
- Handles uncertaintyno0.04
- Measuredno0.04
- Runnableyes0.91
- Worth recommendingno0.38
- Model replicano0.03
- Problem scopescore on a 0–2 scale0.73
- About Jevyes0.98
Signals by Jev jev-1.13.0, card written by DeepSeek V4.1 Flash from the README on 20 Sept 2026.