Is Psalm open source?

Yes. Psalm is open source under the MIT licence. Its source code is on GitHub at vimeo/psalm and is written mainly in PHP.

Yes. Psalm is open source, so the software itself is free to use.

Can I self-host Psalm?

Yes. Psalm can be self-hosted on your own server or infrastructure.

What is Psalm an alternative to?

Psalm is an open-source alternative to Codacy. Other open-source alternatives to Codacy include Semgrep, SonarQube and ESLint.

Is Psalm actively maintained?

Yes. The most recent commit to Psalm was on 13 October 2026, and the latest release is 6.20.0, published on 9 October 2026. The project has 5.9k stars on GitHub.

Psalm: open-source alternative to Codacy

About Psalm

Psalm is a static analysis tool for PHP that helps identify problems in code, including type-related runtime errors and security vulnerabilities. It is free and open-source, and can be used on codebases of various sizes and ages.

On its strictest setting, Psalm can help prevent almost all type-related runtime errors and enables safe coding patterns. It also includes automatic bug fixing capabilities.

Key features

Identifies type-related runtime errors
Detects security vulnerabilities
Supports strict analysis settings
Automatically fixes bugs
Works with large and small codebases

Good fit for

Finding errors in PHP applications
Improving code quality with static analysis

Built with: PHP tools
Tags: php; static analysis; static analysis tool; bug detection; security

Psalm: questions and answers

What is Psalm used for?: Psalm is a free and open-source static analysis tool for PHP that helps identify problems in code, including type-related runtime errors and security vulnerabilities. It is a good fit for finding errors in PHP applications and improving code quality with static analysis.
Is Psalm open source?: Yes. Psalm is open source under the MIT licence. Its source code is on GitHub at vimeo/psalm and is written mainly in PHP.
Is Psalm free?: Yes. Psalm is open source, so the software itself is free to use.
Can I self-host Psalm?: Yes. Psalm can be self-hosted on your own server or infrastructure.
What is Psalm an alternative to?: Psalm is an open-source alternative to Codacy. Other open-source alternatives to Codacy include Semgrep, SonarQube and ESLint.
Is Psalm actively maintained?: Yes. The most recent commit to Psalm was on 13 October 2026, and the latest release is 6.20.0, published on 9 October 2026. The project has 5.9k stars on GitHub.