Using Jev as a merge gate so Opus is only woken on escalation
The author puts a Jev decision layer in front of Claude Code to judge whether a diff can ship, cutting 10,000 decisions from $300 to $0.42.
You're paying your smartest AI model to say "yes" or "no." That's it. That's the whole waste. Every time your coding agent decides whether something is safe to ship, it's running a full, expensive model, just to pick one of three words. Put a cheap decision layer in front of it instead. Opus 5.5 keeps writing the code. Jev reads the diff and hands back one word: > ship: tests pass, diff matches the plan > return: diff drifted past what the plan said > escalate: irreversible, or touches something nobody planned for Jev decides. Opus only shows up when something escalates. here's what it actually checks before answering: > how many files changed, how many lines, did the tests pass, did it touch a database migration. > all of that gets read by plain code, no model involved > then one question decides how bad it'd be if this broke something. if the answer is "hard to fix," it goes to a human no matter what > if it's safe and the model is confident, it ships itself > if it's unsure, it just gets sent back. nothing risky slips through on a guess 10,000 of these a month on your main model: $300. same 10,000 on this layer: $0.42. that's not a typo. that's the whole pitch. paste this into Claude Code: "Add a merge gate to this repo using Jev (TypeSafe): 1. Write a snapshot function: files touched, lines added and removed, test exit code, whether a migration file is touched, whether any touched file falls outside plan.paths. Deterministic only, no model calls. 2. Call jev-1.13.0 with three questions: a Choice (ship / return / escalate) on whether the diff matches the plan, a Score (0 to 2) on blast radius if this shipped and had to be undone, a Noul on whether a human should read it first. 3. In code: if blast_radius is 1.5 or higher, or needs_human is 0.70 or higher, escalate, regardless of the verdict. Else if verdict is ship and confidence is 0.88 or higher, ship. Else, return. 4. Run it in shadow mode for two days: log the decision next to what actually happened, change nothing live. Show me every file as a diff first. No edits until I say go." https://jev-engineering.site
This post quotes another post: x.com/hanakoxbt/status/2101709924828934222