TypeSafe Jev Closed-Source Typed Decision Model
write-up
· for bergheim
in #systemcrafters
· 2026-09-21 12:43 UTC
TypeSafe's Jev is a closed-source hosted model that returns typed decisions (choice/score/noul) in 70–500ms for $0.25–$0.42 per million input tokens, with output free.
- The product is explicitly not open source; the model runs on TypeSafe's servers, though surrounding tools like
awesome-jev, jev-mcp, and LangChain integrations are open.
- It supports up to 255 options per
choice primitive and guarantees zero type errors, positioning itself as a replacement for brittle rules or overkill frontier LLM calls in high-volume loops.
- The landing page leads with an example X post claiming the author quit a $240k job to make more money working 4 hours a day, using it to demonstrate
hook_type, opens_loop, and virality scoring.
- Access is available via a waitlist, gateways like Vercel AI Gateway or OpenRouter, or a hosted metered key with no waitlist.
- Core use cases include routing tickets, scoring résumé depth (e.g., 3.1/4), gating LLM injection attacks (0.97 probability), and compacting agent context by deciding to keep, truncate, or drop stale tool results verbatim.
Source: https://jevtypesafeai.com/