Golang/observability hacker changing the world @typesafeai. alum @docker @honeycombio @Bauplan_labs

San Francisco, CA
still seems expensive to me
If you want to understand how fast AI is improving, look at intelligence per dollar. 1.5 years ago: o1 Pro: $150 / $600 per M tokens Today: GLM-5.3 Flash: $0.15 / $0.50 That’s a ~1000x collapse in price in under 1.5 years, while GLM-5.3 Flash is more intelligent than o1 Pro.
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this feels directionally correct
some good data here about model routing first cursor model router, now openrouter + jev. people keep trying to build routers at _request level_ which is not going to work the fundamental problem is that a prompt without surrounding context is simply not enough signal to judge complexity easiest example to understand this - if you ask “how does this work” in a toy repo with just one html file, any dumb model can do it. but if you send the exact same prompt in linux kernel repo, hell breaks loose. how do you route that prompt? the second problem is prompt caching. it means we can’t frequently change the model during a session in an economic way. one or two missteps here and there, and you find yourself spending more cost than simply using the best model all along the right way to build a router is to do it at task level, not request level. this cannot be done by a model gateway which has to assume everything is a single continuous session. it needs to be a harness layer capability which can make use of a multi-agent architecture a smart enough model first needs to do some digging and understand the complexity of the ask, then delegate substantial sub tasks to models with appropriate intelligence - even this is very hard to get right
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Nathan LeClaire retweeted
I made Jev do a stupider thing, be a NAND gate, so it can run a 4-bit ALU. Adding 7 + 5 = 12 takes 116 gates, 7.6 seconds, $0.0018, and a compound 84% probability. Billions of these will play Doom one day. I've asked Opus 5.5 to make a video about it, Nolan style.
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Nathan LeClaire retweeted
jev in production, starting with the most important use-case.
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うっす、JEVブロのみんな!!TypeSafe HQでは日本の #jevgang のことをマジでずっと考えてる。今日、レイテンシが改善するはずの変更をぶっこんだぜ。もしJEVのスクリプトとか数字とか、ぜひ試して、効いたかどうか教えてくれ頼む
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do you feel what’s about to happen yet?
It’s been a week since I moved one of eval datasets from Gemini 3.1 to Jev by @typesafeai for LLM judging. The results so far: - No meaningful change in scoring accuracy - ~200× cheaper (~$0.01 → ~$0.00005 per judge) - ~50× faster (~10s → ~0.2s median) - ~50% fewer input tokens, 87% fewer output tokens But not everything’s perfect, more details in the thread
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Nathan LeClaire retweeted
we have been running jev in prod for a week and for the things it's good at, it absolutely mogs the oss models receipts attached in the blog polylane.com/blog/we-swapped…
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Nathan LeClaire retweeted
you can use Jev judgments to build your own “embedding” of agent traces where every dimension has a name. E.g. conversation signals from chat agents: [user_frustrated, follow_up, corrected_agent, satisfied] [0.7, 0.8, 0.1, 0.0] Now you can cluster or search sessions like “frustrated users who had to correct the agent,” and see exactly why each one matched. Works both ways too: search for the happy users. Just as important to see what’s going right :)
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Nathan LeClaire retweeted
On four agent benchmarks, Jev Router solved 82% more tasks than our Auto Router (237 vs 130 of 423).
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Nathan LeClaire retweeted
Replying to @allietheicon
jevinterp lfg
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Nathan LeClaire retweeted
From a practical point of view, you should be using Jev today in your rubric-grading workflows (eval, RL rewards). The next release of Autorubric (landing tomorrow) will natively support Jev-style models in addition to regular LLMs.
I spent some time investigating @typesafeai's Jev and striking to see them use a similar abstraction as autorubric -- released 8 months ago and to be presented at @COLM_conf next month. Our criterion types map 1:1 to Jev's Noul/Score/Choice: arxiv.org/abs/2603.00077
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Nathan LeClaire retweeted
The Jev Router is our most transparent router to date, and it benchmarks very well! See how it picks the model in the Chatroom sidebar, including cache-aware cost tradeoffs:
Introducing typesafe/jev-router: a cache-aware model router powered by Jev and @typesafeai The Jev Router picks the best model and reasoning effort for each request, balancing quality, speed, and cost. Here's how it works 👇🏻
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YES! THIS IS WHAT I'M TALKING ABOUT! We should be able to leverage both decision making and K/V cache by scoring and deliberately making tradeoffs
Replying to @OpenRouter
Jev Router keeps a model that works for the rest of the session. It can raise or lower effort without switching models. It switches only when the expected gain is larger than the cost, including the cached chat it would lose.
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Nathan LeClaire retweeted
How to use jev #1: As an embedder
I've been using Jev for all kinds of things. This morning I had a realization I kind of like: Use it to make non-black-box embeddings. Instead of an embedding model spitting out 1,536 numbers that mean nothing, you ask Jev questions about each document. The answers become the vector. An email in Cora: "I got charged twice this month, pls fix asap" [is_customer, urgent, about_billing, needs_reply] [1.0, 0.9, 1.0, 1.0] A newsletter: [0.0, 0.0, 0.0, 0.1] A friend asking about lunch: [0.0, 0.1, 0.0, 0.7] Then it's just old-school cosine similarity search. Search "billing issues from customers" as [1, 0.5, 1, 0.5] and the double charge comes out on top. Same idea for our articles at Every: [is_tutorial, about_ai, contrarian, beginner_friendly] Or support tickets: [is_bug, angry, churn_risk, enterprise] Every number has a name, so you can see why something matched. Need a new dimension? Add a question. Want urgent stuff first? Change the query vector. Trying this in @CoraComputer now to make search fast.
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We couldn't do what we do @typesafeai without our partners at @modal 🙏 thanks Modal team!
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Nathan LeClaire retweeted
You've never routed like this before. @OpenRouter is bringing Jev to all of your LLM calls, so your agentic workflows never have to waste a token again. As always, faster, cheaper, more intelligent. Go build the future.
Introducing typesafe/jev-router: a cache-aware model router powered by Jev and @typesafeai The Jev Router picks the best model and reasoning effort for each request, balancing quality, speed, and cost. Here's how it works 👇🏻
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Nathan LeClaire retweeted
DSPy methodology 🤝 System One Program, don't prompt!
DSPy 3.4.0 was just released! This release includes native support for Jev and System one models inside of DSPy! Use it with compatible signatures. This release also includes a brand new optimizer, ReAnchor, specifically for calibrating outputs with confidence.
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.@typesafeai platform team every day
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Nathan LeClaire retweeted
DSPy 3.4.0 was just released! This release includes native support for Jev and System one models inside of DSPy! Use it with compatible signatures. This release also includes a brand new optimizer, ReAnchor, specifically for calibrating outputs with confidence.
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Nathan LeClaire retweeted
jev + opus 5.5... i simply can't comprehend why everyone isn't building this yet. in my workflow, this cut costs and time by ~80%. i think it's one of the best ways to use it. → pick relevant project notes before loading the context → route suitable tasks to a faster worker → choose a recovery path when a tool fails → run focused checks before the full test suite opus handles the hard reasoning. jev picks from options the harness prepares and validates. i explain how to build the decision layer in the article below:
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give us two years
me explaining why we can't run a classifier on every event
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