gscan

GScan is a tool for validating Ghost themes. It produces detailed reports of issues where themes need to be modified in order to be compatible with a specific version.

It is actively capable of dealing with the current and last major versions of Ghost (so at the time of writing v4, v3, v2 and v1).

GScan works on a system of rules. Each rule has a way to check whether it passes or fails and has help content which describes how to fix it. Each rule is also marked with an error level:

• Errors: issues that will cause your theme to not work properly. These must be fixed.
• Warnings: these are usually related to deprecated features. These should be fixed.
• Recommendations: these are advisories about best practice. Fixing these will improve your theme.
• Features: detected features which may impact on compatibility. Nothing to do!

In addition, an error can be marked as fatal. A fatal error means, left unchecked a Ghost publication would throw 500 errors on certain pages because of the detected out-of-date or erroneous code.

Usage

There are 4 ways to use gscan to validate your theme:

1. Inside Ghost

Gscan is pre-installed in Ghost. If there are theme errors, Ghost will show them on boot in the console logs and in the UI (Ghost Admin).

2. Web usage

Visit https://gscan.ghost.org and upload your zip to our online version of Gscan.

3. CLI usage

Install using yarn / npm:

yarn global add gscan / npm install -g gscan

To run a local directory through the checks:

gscan /path/to/theme/directory

To run a local zip file through the checks:

gscan /path/to/theme.zip -z

By default, GScan scans themes for the latest Ghost version compatibility. You can also specify a Ghost version by using the following parameters (for Ghost 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0):

--v1 or -1 --v2 or -2 --v3 or -3 --v4 or -4 --v5 or -5 (default) --v6 or -6 or --canary

Examples:

gscan /path/to/theme.zip -z -1 - scan a theme in a zip file for Ghost 1.0 compatibility gscan /path/to/theme/directory --v2 - can a theme in a directory for Ghost 2.0 compatibility gscan /path/to/theme/directory - scan a theme for Ghost 5.0 compatibility

4. Lib usage

Install using yarn/npm and then:

var gscan = require('gscan');

gscan.checkZip({
    path: 'path-to-zip',
    // Pass in a folder to check
    // if you need to check the theme for a different
    // major Ghost version, you can pass it. Currently
    // v1, v2, v3, v4, v5 and v6 are supported. Default is
    // the latest Ghost version 5.0:
    // checkVersion: 'v5',
    name: 'my-theme'
}).then(function (result) {
    console.log(result);
}).catch(function(err) {
    console.log(err);
});

Development

Run in browser (for zip uploads)

• Either dev mode: yarn dev
• Or standard server: yarn start
• View: http://localhost:2369

Run on command line

• zip file: ./bin/cli.js -z /path/to/your/theme.zip
• directory: ./bin/cli.js /path/to/directory

Publish

(Core team only)

• yarn ship

Tools

When developing new rules or testing gscan following tools are great to have in the toolbelt:

• astexplorer - absolutely awesome Handlebars AST fiddler, helpful when testing out new ideas and exploring what's possible through AST parser;

To Do

• Support for running the checks against a GitHub repository
• Many, many more checks
• Detailed advice for each check/result
• Compatibility report
• Feature listing

Copyright & License

Copyright (c) 2013-2025 Ghost Foundation - Released under the MIT license. Ghost and the Ghost Logo are trademarks of Ghost Foundation Ltd. Please see our trademark policy for info on acceptable usage.