TypeSafe's official Claude Code skill teaches agents to use Jev for judgment calls
The roughly 1,300-word skill has Claude Code read live docs first, keep rules in normal code and use Jev only for judgment, with a test showing 13 questions in one call cost 12.2x less.
TypeSafe released an official skill that teaches Claude Code to build on Jev. It's one of the best-written skills I've read. About 1,300 words, and nearly every line stops the agent from guessing. It makes Claude Code → read TypeSafe's live docs before writing any code → keep rules, maths and lookups in normal code, and use Jev only for judgment calls → pick the right question type. Choice for one of a set, Noul for yes or no, Score for how much The line that saves the most money is to ask independent questions together, in one call. TypeSafe tested it in their own cookbook. 13 questions in one call came out 12.2x cheaper and 10x faster, with the same answers. Install it in Claude Code claude plugin marketplace add typesafe-ai/skills claude plugin install typesafe@typesafe-ai The skill is free and MIT licensed. You'll need a TypeSafe API key to use Jev.