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Using a linter on your Protobuf sources enables you to enforce consistency and keep your API definitions in line with your chosen best practices. We recommend enforcing lint rules whether you're working on a small personal project or maintaining a large set of Protobuf definitions across a major organization, but it's especially important for users and organizations that continually onboard new engineers who aren't yet experienced with Protobuf schema design.

The buf CLI provides linting functionality through the buf lint command. When you run buf lint, buf runs a set of lint rules across all of the Protobuf files covered by a buf.yaml configuration file. By default, the buf CLI uses a curated set of lint rules designed to guarantee consistency and maintainability across Protobuf schemas of any size and purposebut without being so opinionated that it restricts you from making the design decisions you need to make for your individual APIs.

Some features of the buf CLI's linter:

  • Selectable configuration of the exact lint rules you want, including categorization of lint rules into categories. While we recommend using the DEFAULT set of lint rules, you're free to go your own way.

  • Editor integration. The default error output is easily parsed by most editors, which allows for a tight feedback loop for lint errors. Currently, we provide Vim and Visual Studio Code integration but we may support other editors in the future, such as Emacs and IntelliJ IDEs.

  • Speed. buf's internal Protobuf compiler uses all available cores to compile your Protobuf schemas while maintaining deterministic output. Additionally, it copies files into memory before processing. As an unscientific example, buf can compile all 2,311 .proto files in googleapis in about 0.8 seconds on a four-core machine, while it takes protoc 4.3 seconds to do so on the same machine. While both are fast, the buf CLI provides near-instantaneous feedback, which is especially useful for editor integration. buf's speed is directly proportional to the input size, so linting a single file only takes a few milliseconds.