1-1-1 Best Practice

The “1-1-1” best practice advocates structuring definitions with one top-level entity (message, enum, or extension) per .proto file, corresponding to a single proto_library build rule. This approach promotes small, modular proto definitions. Key benefits include simplified refactoring, potentially improved build times, and smaller binary sizes due to minimized transitive dependencies. Rationale The 1-1-1 best practice is to keep every proto_library and .proto file as small as is reasonable, with the ideal being: