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Building a Harness with Jev

Blog post from LangChain

Post Details
Company
Date Published
Author
Sydney Runkle, Hunter Lovell
Word Count
1,103
Company Posts That Month
21
Language
English
Hacker News Points
-
Post removed?
No
Summary

Jev, developed by TypeSafe AI, is a non-generative “System One” model designed to make fast, structured decisions within AI agent workflows, where repeated LLM calls can otherwise increase latency and cost. Rather than producing text, it evaluates a provided state and returns typed probabilistic answers to choice, scoring, or yes-or-no questions, with multiple questions evaluated in parallel; TypeSafe AI reports substantially faster and less expensive classification performance than comparable LLM approaches. LangChain supports Jev through its TypeSafeClassifier integration, allowing developers to submit text, structured data, or messages and receive classification results that can guide agent behavior. Suggested applications include routing requests to appropriately capable models based on task complexity and using Auto Mode middleware to assess potentially risky tool calls before execution, while leaving open-ended reasoning and text generation to conventional LLMs.

Trends Found in this Post
Trend Post Mentions Total Month Mentions Posts Companies MoM
Jev 18 2,144 89 49 -
LLM 9 6,025 1,161 240 +15%
Reinforcement learning 1 160 67 39 +68%
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