Google API Linter

What Google API Linter is

Google API Linter checks API surfaces defined with Protocol Buffers against Google API standards set out in API Improvement Proposals (AIPs). When it can, it recommends corrections for common errors and inconsistencies. Rules are organized by AIP block. Core and client library rules are active by default; Cloud rules are off unless enabled. Developers can adjust rule selection using command-line flags, a configuration file, or comments in proto files. The CLI reports findings in YAML, JSON, GitHub format, or a summary table, with YAML as its default. The tool is self-hosted, and its installation instructions use Go to place the CLI in the local Go binary directory. It is free and open source under Apache 2.0, which also applies to its documentation. The project accepts contributions, including new lint rules, and requires every rule to match an AIP that mandates the behavior. Its coverage is limited: some AIP guidance cannot be expressed as lint rules, and some guidance that could be encoded may not yet have a rule. The project also does not follow semantic versioning, since changes to rules can make previously clean files produce findings. Developers can visit the project website for documentation and links to GitHub for the source and issue reporting.

Who it suits

Google API Linter suits developers who define APIs with Protocol Buffers and want to check them against AIP requirements. It may also suit teams that want to configure rule groups and use lint output in CI/CD workflows.

Limits

Some AIP guidance cannot be expressed as lint rules, and some guidance that could be encoded may not yet be covered. Cloud rules are disabled by default.

Getting started

1. Open https://linter.aip.dev/ for the project documentation.
2. Install the CLI with Go into the local Go binary directory, following the installation instructions.
3. Configure rule selection with CLI flags, a configuration file, or proto comments.
4. Run the CLI and choose YAML, JSON, GitHub, or summary table output.

Verdict

Choose Google API Linter if you define APIs with Protocol Buffers and need checks tied to AIP requirements, with configurable rules and several output formats. Look elsewhere if you need complete AIP guidance coverage, since some guidance cannot be linted and some possible rules may not exist yet.