A GitHub Action that formats your code using the IntelliJ formatter.

Both examples implement caching of downloaded IDE files. Cache generation might take a while on the first run, but saves bandwidth and is faster later on.
NOTE: If the actions fails due to the formatting changing files, cache will not be saved.

Formats all files that are supported by the formatter in your repository and creates a pull request whenever there's a push to the main branch, including pull requests to it:

name: IDEA Format

on:
  push:
    branches: ["main"]
  pull_request:
    branches: ["main"]

jobs:
  formatting:
    runs-on: ubuntu-latest
    steps:
      - if: github.event_name != 'pull_request'
        uses: actions/checkout@v6
      - if: github.event_name == 'pull_request'
        uses: actions/checkout@v6
        with:
          ref: ${{ github.event.pull_request.head.ref }}
      - name: Cache IDEA
        uses: actions/cache@v5
        with:
          path: /home/runner/work/_temp/_github_workflow/idea-cache
          key: ${{ runner.os }}-idea-cache
      - uses: notdevcody/intellij-format-action@v4
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Formats all files that are supported by the formatter in your repository and directly commits the changes whenever there's a push to the main branch, including pull requests to it:

name: IDEA Format

on:
  push:
    branches: ["main"]
  pull_request:
    branches: ["main"]

jobs:
  formatting:
    runs-on: ubuntu-latest
    steps:
      - if: github.event_name != 'pull_request'
        uses: actions/checkout@v6
      - if: github.event_name == 'pull_request'
        uses: actions/checkout@v6
        with:
          ref: ${{ github.event.pull_request.head.ref }}
      - name: Cache IDEA
        uses: actions/cache@v5
        with:
          path: /home/runner/work/_temp/_github_workflow/idea-cache
          key: ${{ runner.os }}-idea-cache
      - uses: notdevcody/intellij-format-action@v4
        with:
          push-type: "commit"

While none of these inputs are mandatory, you can specify them to modify the action's behavior.

Pattern for files to include. Supports glob-style wildcards. Multiple patterns can be separated by commas.
Default: *.*

Path to project directory. The formatter is executed recursively from here.
Must be relative to the workspace.
Default: .

Type of push to perform.
Options are commit, pull-request or none.
Default: pull-request

The title to use for the commit or pull request.
Default: IntelliJ Code Format

The description to use for the pull request.
Unused for commits.
Default: Empty

Fail if any files were changed by the formatter.
Default: true

Version of IntelliJ IDEA to use.
Default: 2025.2.6

A path to IntelliJ IDEA code style settings .xml file.
Leave default if you want the formatter to use .editorconfig files.
Default: unset (-allowDefaults argument)

Mute the formatter output. Action output will still be logged.
Default: true

Outputs the number of files which were formatted.
Zero if none changed.