Squawk

Overview

Squawk is an open-source linter and language server for PostgreSQL SQL and migrations. It is best suited to developers who want migration-risk checks in their editor and pull-request workflow. Its focused checks can flag changes that may interrupt reads or writes, but developers must decide how to address them.

Key features

Squawk’s rules flag potentially unsafe statements, incompatible changes, and migration patterns that can block database reads or writes. Messages include examples and reasoning, helping developers understand why a statement warrants attention. That makes the tool useful as an early warning in migration work, but it does not provide automatic fixes or custom rules; remediation and any organization-specific checks remain outside its scope.

The CLI lints SQL files and can exclude rules and paths. Configuration also lets teams set a PostgreSQL version and specify whether files are assumed to run in transactions, which helps tailor checks to a project’s migration conventions. Some rules are disabled by default, so teams should review the rule set and explicitly enable relevant opt-in checks.

A language server and VS Code extension bring linting into the editor. For pull requests, the GitHub Action can lint modified SQL migrations; comments can be added through the upload-to-github command or GitHub App. The App requires Pull Requests write permission to comment. For CI outside GitHub Actions, Squawk recommends configuring the App, with CircleCI as an example.

Installation routes include npm, PyPI, release binaries, Docker, and VS Code. A browser playground uses WebAssembly to lint SQL without requiring a local installation, making it a convenient way to try a check, though it is not a substitute for integrating migration linting into a project’s workflow.

Pricing

Squawk is free and open source. There are no paid plans or free-trial terms to weigh; its trade-offs are its PostgreSQL-only focus and the work required to handle findings and configure opt-in rules.

Platforms

Squawk is available through its CLI and editor extension, a browser playground, Docker, package managers, and release binaries. The releases page lists macOS and Linux binaries as well as VS Code extension packages. Its platform labels also include Android, iOS, Windows, API, and self-hosted, but the documented binary releases are for macOS and Linux.

Who it's for

Choose Squawk if your team works with PostgreSQL schema changes and wants checks at more than one point in the workflow: while editing SQL, from the command line, or on pull requests. It is less suitable for teams that need multiple SQL dialects, automatic repairs, or custom lint rules.

Pros and cons

Pros: Risk-focused rules explain findings with examples and reasoning, giving developers context to assess migration warnings.

Pros: Editor, CLI, browser, and pull-request routes let teams place checks where they work.

Pros: Free and open source, with configuration for PostgreSQL version, transaction assumptions, excluded rules, and paths.

Cons: PostgreSQL is the only supported dialect, so teams working across other SQL dialects need another tool for those checks.

Cons: Findings are not automatically fixed, and custom rules are not supported; developers must make changes themselves and cannot add bespoke checks.

Cons: Some rules require explicit opt-in, so relying on defaults alone may leave relevant checks inactive.

Alternatives

For a different SQL linting or formatting tool, compare SQL Linters and Formatters.

Consider SQLCheck as another free, open-source command-line option for Linux, macOS, and Windows. Choose sqlfmt if a free browser-based formatter that runs through WebAssembly is a better fit. Poor SQL is another free option with online and offline formatting and SSMS/Visual Studio plugin support.

Sqruff, TSQLLint, JSQLFormatter, Sleek, and SQL Formatter are also alternatives to compare.

Verdict

Squawk is a strong fit for PostgreSQL developers who want migration risks surfaced in local, editor, or pull-request checks without paying for a plan. Its explanations and workflow integrations are the main reasons to choose it; look elsewhere if you need broader dialect coverage, custom rules, or automatic fixes.