📰 Story

Show HN: Chunk sidecars for validating agent-generated code before pushing to CI

Hi HN! My name is Olaf, I work at CircleCI as a technology advisor in the CTO office, came in through the acquisition of my company Vamp.io (progressive delivery for microservices on k8s) in 2021. Wanted to hear the HN community feedback and thoughts on a project we think could be very interesting when adding AI coding agents to the SDLC and your CI pipelines. Our team at CircleCI built Chunk sidecars after repeatedly running into the same issue internally: by the time our CI catches a failure, the agent has already moved on and most of the useful context is gone. The basic idea of Chunk sidecars is to move fast lightweight validation into the inner development loop. Chunk sidecars runs scoped “microbuilds” inside a lightweight microVM that mirrors your CI environment. It tries to auto-detect your stack and test commands, syncs changes from the agent session, and runs validations before commit/push. A few implementation details that might be interesting: validation hooks trigger automatically during agent stop/evaluation events warm snapshots keep startup times low validations run against environments matching the CI stack instead of local machine state microbuilds only run the relevant slice instead of the entire pipeline In our own experiments we measured: ~27 second average microbuild compute ~5 minutes total billable compute for equivalent full CI runs 3x–5x lower token usage in retry loops The compute comparison is billable compute vs billable compute, not wall clock tim