Shut up and calculate: Jev's new AI primitives for coders

TypeSafe’s Jev, launched last week, behaves differently from the standard frontier models that everyone is now used to and has therefore quickly attracted plenty of scrutiny and interest as developers explore how to work with this technology.

Jev’s output is more restricted than the chatty ask-me-anything approach of other LLM-powered chatbots.

Basically, Jev is a classifier with brains.

When given a set of data, it returns predefined “typed” decisions that the developer decided on beforehand, along with probability distributions and, for some query types, a confidence level that can then be used to make decisions and automate processes.

As Brian Eno has often said, greater limitations frequently spur greater creativity.

In the week since Jev’s release, developers have flocked to the service, at least to test it out.

FPV Ventures partner Nikunj Kothari set up a site called Jevable to collect prototype Jev apps posted on X.

Jevable hosts developer tools and productivity utilities, some frivolous.

One app translates plain English into “unnecessarily fancy prose.” Another allows the user to add an “Urgency” column to spreadsheet rows, which Jev can then rate from “no follow-up needed” to “urgent.” Another app gives people a virtual way to see what clothes would look like on them.

In a mockup, Jev reads the transcript, consults a list of clothing and changes the outfits on an image of the user in real time.

Cost is $0.0011 per decision, and it takes Jev ~620 ms to show how awful you will look in that Hawaiian shirt you're thinking of buying.

Gaming hacks are another favorite.

There are apps for speeding through Doom, Tetris, League of Legends, Settlers of Catan, and chess (where Jev lost to the GLM 5.3 open-weight model but was far cheaper to run).

Perhaps the most extreme expression of coder curiosity has been to use Jev to emulate a CPU, which is useful mostly in terms of entertaining the geek fixation with recursion.