Proto Wire Break Check

It reads a .proto file and applies 17 rules that catch edits which still compile but change what an already-deployed reader sees: a field number used twice, a reserved number taken back, two fields that share a JSON key, a proto3 enum that does not start at 0. Each finding names the line and the edit that keeps the wire intact.

Backend and platform engineers who own a gRPC or Connect service and review .proto changes from teammates or AI agents. If a schema edit of yours ships to a mobile client, a partner integration, or a Kafka topic you cannot redeploy in the same hour, this is the class of mistake that costs you a rollback.

Roughly half of these edits are legal proto, so protoc never mentions them - an unreserved hole in the numbering, a bare scalar where absent and zero differ, a removed enum state. The rest fail a build you have to wait for. And a language model tells you the file compiles, which is true and is not the question: it cannot know which tags your deployed readers still write.

Free and without a key: the whole check on the file you have open, all 17 rules, every finding with line numbers. The 27-line sample file returns 18 findings, 10 of them errors. The licence key adds the workspace-wide sweep and the written PROTO-WIRE-AUDIT.md plus audit.json you can commit or gate a build on.

A contract backend engineer runs $60+/hour on the public marketplaces, and walking one service's schema history to answer which field numbers are already spent is an afternoon of that. The full version is $29 once, one licence key per person or team seat, with a 7-day full refund.