🤖 A GitHub action to take backups from OverLeaf which is an Online LaTeX Editor.

Ensure that you have set OVERLEAF_COOKIE and OVERLEAF_PROJECT_ID as GitHub secrets. Head over to this link to get more info on how to add secrets to a GitHub repo.

You may also need to edit your project settings to allow workflows to write to your repository. Click on Settings -> then Actions and ensure that under Workflow permissions you've provided Read and write permissions to workflow.

Once you have set the secrets. Just create a new workflow file in .github/workflows/FILE_NAME.yml and add the following content.

name: Overleaf Sync with Git
on:
  schedule:
    - cron: "0/5 * * * *"
  push:
  workflow_dispatch:
      
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - name: Delete Old Artifacts
      uses: actions/github-script@v6
      id: artifact
      with:
        script: |
          const res = await github.rest.actions.listArtifactsForRepo({
            owner: context.repo.owner,
            repo: context.repo.repo,
          })

          res.data.artifacts
            .forEach(({ id }) => {
              github.rest.actions.deleteArtifact({
                owner: context.repo.owner,
                repo: context.repo.repo,
                artifact_id: id,
              })
            })

    - name: Fetch the latest version from overleaf server
      uses: subhamx/overleaf_sync_with_git@master
      with:
        OVERLEAF_PROJECT_ID: ${{ secrets.OVERLEAF_PROJECT_ID }}
        OVERLEAF_COOKIE: ${{ secrets.OVERLEAF_COOKIE }}

    - name: Upload to Project Artifacts
      uses: actions/upload-artifact@v4
      with:
        name: project
        path: ./artifacts/

    - uses: actions/checkout@v2
      with:
        path: repo/
    
    - run: |
        cd repo/
        mkdir -p overleaf_remote_src
        cp -r ../artifacts/* ./overleaf_remote_src
        git config user.name "Overleaf Sync Bot"
        git config user.email "[email protected]"
        git add .
        if [[ $(git diff HEAD --stat) == '' ]]; then (echo 'Working tree is clean') 
        else (git commit -m "Sync with overleaf remote"  && git push) fi

The OVERLEAF_PROJECT_ID secret can be copied from the Overleaf URL of the project you want to sync. The project ID of the following URL https://www.overleaf.com/project/12345a6b7890cdef1a23456b would be 12345a6b7890cdef1a23456b

This value is a bit trickier to find. It is used to authenticate the action against the Overleaf servers. It is part of the cookie that Overleaf sets in your browser after you successfully login. The process of extracting the required value differs from browser to browser.

In either case open the developer console (Hotkey F12). For Firefox look for the Storage tab and then select Cookies. For Edge the same setting can be found under Application and then Storage -> Cookies. Look for a cookie with the name overleaf_session2 and copy its value.

IMPORTANT: I would recommend that after you copy overleaf_session2 cookie and put it in the GitHub actions secret, please delete the cookie from the browser. And then start a new browser session (by logging in again) if required. Please do not logout, it will make overleaf revoke the credentials. If you follow the above point, then the cookie should remain active for atleast 2 months, and the workflow should work without any issues. We've tested it in early 2023 by working a sample workflow for couple of months, and you can find the insights here.

In the following case, please put s%3A3xxaFrMMXWi1xxxtm23BjBYJTc8GAb7P.xxyxxzhxxrPJxxovoxxaafnxx9ZorxxP6YxxzxfxxIo as the OVERLEAF_COOKIE value.

The OVERLEAF_HOST parameter can be used to sync with a self-hosted Community Edition or Server Pro Overleaf instance. The parameter defaults to www.overleaf.com, when not set.

To set the value, just add the environment variable to the actions step, as seen below:

    - name: Fetch the latest version from overleaf server
      uses: subhamx/overleaf_sync_with_git@master
      with:
        OVERLEAF_PROJECT_ID: ${{ secrets.OVERLEAF_PROJECT_ID }}
        OVERLEAF_COOKIE: ${{ secrets.OVERLEAF_COOKIE }}
        OVERLEAF_HOST: ${{ secrets.OVERLEAF_HOST }}