Protolint is a pluggable linting and fixing utility for Protocol Buffer files (proto2 and proto3). It operates without a compiler for fast performance and enforces the official Protocol Buffer style guide. Key features of Protolint: - Fast linting that works without a Protocol Buffer compiler - Automatic fixing of style guide violations - Plugin system for loading custom lint rules - Rule suppression via inline comments for maintaining API compatibility - MCP server support for AI assistant integration - Integration with editors, GitHub Actions, and CI pipelines

protolint

[](https://github.com/yoheimuta/protolint/releases) [](https://github.com/yoheimuta/protolint/blob/master/LICENSE) [](https://hub.docker.com/r/yoheimuta/protolint)

protolint is the pluggable linting/fixing utility for Protocol Buffer files (proto2+proto3):

Demo

Once MCP server configured, you can ask any MCP clients like Claude Desktop to lint and fix your Protocol Buffer files like this:

Also, vim-protolint works like the following.

MCP Server

Usage

protolint --mcp

For detailed documentation on how to use and integrate protolint's MCP server functionality, see the MCP documentation.

Installation

Via Homebrew

protolint can be installed for Mac or Linux using Homebrew via the yoheimuta/protolint tap.

brew tap yoheimuta/protolint
brew install protolint

Since homebrew-core includes protolint, you can also install it by just brew install protolint. This is the default tap that is installed by default. It's easier, but not maintained by the same author. To keep it updated, I recommend you run brew tap yoheimuta/protolint first.

Via GitHub Releases

You can also download a pre-built binary from this release page:

In the downloads section of each release, you can find pre-built binaries in .tar.gz packages.

Use the maintained Docker image

protolint ships a Docker image yoheimuta/protolint that allows you to use protolint as part of your Docker workflow.

❯❯❯ docker run --volume "$(pwd):/workspace" --workdir /workspace yoheimuta/protolint lint _example/proto
[_example/proto/invalidFileName.proto:1:1] File name should be lower_snake_case.proto.
[_example/proto/issue_88/oneof_options.proto:11:5] Found an incorrect indentation style "    ". "  " is correct.
[_example/proto/issue_88/oneof_options.proto:12:5] Found an incorrect indentation style "    ". "  " is correct.

From Source

The binary can be installed from source if Go is available. However, I recommend using one of the pre-built binaries instead because it doesn't include the version info.

go install github.com/yoheimuta/protolint/cmd/protolint@latest

Within JavaScript / TypeScript

You can use protolint using your nodejs package manager like npm or yarn.

$ npm install protolint --save-dev

This will add a reference to a development dependency to your local package.json.

During install, the postinstall.js script will be called. It will download the matching protolint from github. Just like @electron/get, you can bypass the download using the following environment variables:

| Environment Variable | Default value | Description | |-------------------------------|---------------------------------------|-----------------------------------------------| | PROTOLINT_MIRROR_HOST | https://github.com | HTTP/Web server base url hosting the binaries | | PROTOLINT_MIRROR_REMOTE_PATH | yoheimuta/protolint/releases/download | Path to the archives on the remote host | | PROTOLINT_MIRROR_USERNAME | | HTTP Basic auth user name | | PROTOLINT_MIRROR_PASSWORD | |