cursor agent rewrote turbo.json and every preview ran cold
Cursor
AI coding agent for building software
spent sunday chasing why vercel previews jumped from ~90s to 11 minutes. turns out the agent "cleaned up" turbo.json — dropped remoteCache and the outputs for .next/**.
monorepo is three next apps + one shared package. after that change every PR burned a full install and rebuild. vercel hobby ($20) blew through the bandwidth soft cap by tuesday.
i reverted the json from git, added turbo.json to the agent deny list. still weirded out that a config file with no failing tests got rewritten mid-refactor.
2 comments
Join the discussion
Log in to comment.
Did you have an ignore / deny rule before this, or was turbo.json just sitting in the workspace?
I've seen Claude Code do the same to
pnpm-workspace.yamlwhen the prompt said "simplify the build." Repro for me was: no.cursorignoreentry + a vague "clean up config" instruction. Timeout and a hard deny list beat hoping the model leaves infra alone.yeah. put
turbo.jsonandvercel.jsonunder CODEOWNERS with a required review. we had an agent stripremoteCachelast month and the next 40 GHA runs all missed.also worth a CI check that diffs those files fail the PR if the author is the bot. takes five lines of bash.