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IndyDevDan · 35 Min Video · Sept 28, 2026

Levels Of Jev For AI Agents

How a tiny, cheap, fast question-answering model takes the small decisions off your big, expensive AI, from a simple yes or no up to an AI that decides on its own when to ask it.

10 LevelsAbout 12 Min ReadLesson Video

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Lesson video made from the original, in plain English. Watch The Original On YouTube

The Big Idea

Jev, made by a company called TypeSafe, is not a chatbot. It answers narrow questions and nothing else. You hand it three things, and it hands back an answer plus how sure it is, usually in under a second.

The creator's point: stop sending every small decision to the biggest, most expensive AI. Keep the big AI for the real work, and let a small model like Jev make the quick calls along the way. It is "Jev and your AI", never "Jev instead of your AI".

Each answer can be one of three shapes: a yes or no, a pick one from a list, or a score on a scale you set.

The factsWhat is going on right now (a message, a ticket, a command)
The question"Is this a scam attempt?" "How urgent is this?"
The choicesYes/no, a short list, or a score range, each with your own meaning
Back comesThe answer and a sureness number, like 0.94, in about 300 ms

Why It Matters: The Cost

Same question asked one million times, as the video priced it.

ModelTimes Jev's Price
Jev1x (about $20 per million)
DeepSeek V4 Flash (closest rival)4x
Gemini 3.8 Flash44x
Other big-name models80x to 300x
Fable 5.1600x (about $11,000 per million)

At that price, a check you would never pay a big AI to run on every single message becomes something you can run on everything.

The 10 Levels

Levels 1 to 5 are Jev on its own. Levels 6 to 10 put Jev inside an AI assistant as one of its tools. Each level links to that moment in the original video.

What It's Not For

  • Long jobs. It does not work for hours on a task. That stays with the big AI.
  • Driving a screen, playing games, flying a drone. He calls those clickbait uses.
  • Replacing the big AI. It makes the small calls; the big AI still writes, fixes and edits.
  • Trusting it blind. His closing rule: the only test that counts is your own real work. Try it on your own examples side by side with the AI you use now before relying on it.

Words To Know

Jev
A small model that only answers set questions with set answer choices. Fast and very cheap.
"System One" Model
TypeSafe's name for this kind: quick gut-call thinking, as opposed to slow step-by-step reasoning.
Confidence
How sure Jev is, from 0 to 1. 0.99 is near certain; 0.64 is a lean.
Agent
An AI that works through a task on its own using tools: reading files, running commands, browsing.
Harness
The setup around an agent: its tools, its rules, and the checks that run before it acts.
Hook / Guard
A check that runs automatically every time the agent tries to do something, and can stop it.
Context
Everything the AI is holding in its head for the current job. Bigger means slower and pricier.
Compact
Boiling the AI's working memory down to a summary so it can keep going fresh.
Prompt Injection
A message written to trick an AI into ignoring its rules ("ignore all previous instructions...").
Router
A step that decides which AI, helper or process should handle a request.
Pi Agent
The AI assistant he built and tests with in the video.

Don't Mix These Up

JevAnswers one narrow question about facts you hand it. Under a second, fractions of a penny.
Big AI (Opus, Fable, Gemini)Thinks, writes, plans and does the work. Slower and far more expensive.
Pick One (Level 2)Chooses a single label from a list, like "bug, normal priority".
Scoring (Level 3)Grades several things separately; your own math adds them into one total.
Reading A FileThe AI loads the whole file into its memory. Needed when it must change the file.
Asking About A File (Level 8)Jev reads it and answers one question; the AI's memory stays clean.
Level 6: You Set The ChecksJev checks every action automatically, whether the AI wants it or not.
Level 10: The AI AsksThe AI decides for itself when a quick Jev question would help.

Where This Fits For Us

Ideas only, nothing built. The full researched plan, with all 20 spots mapped, is in Lesson 2: Jev + Eve.

  1. Sale and front checklist scoring is a Level 1 and Level 3 job: "Did the agent ask about the doctor? Yes or no, how sure?" for each line, added up by our own weights. A low-sureness answer could go to a person instead of being marked missed.
  2. Claude's and Eve's safety checks are Level 6: a quick "could this not be undone?" question on every action, catching risky moves nobody thought to list.
  3. Sorting incoming Discord, email and compliance notices is Level 2 and Level 5: pick a type and urgency, then send it to the right place.
  4. Eve's 10-minute check and nightly run could use Levels 8 and 9: ask quick questions about many files and sheets without loading them all into her head, which saves cost on every run.
One limit to plan around: Jev is an outside service. Anything with client details, like call transcripts, would leave the building to get checked. Those would need the client details stripped out first, or a check that runs on our own machine.
Breakdown written in my own words from the video's spoken words and screen. The lesson video is made by Google's notebook tool. The video's free example code: github.com/disler/ten-levels-of-jev