jampack caches image processing to avoid lengthy and redundant image resizing and compression. The cache dramatically reduces the processing time of jampack.

The cache is stored in the folder .jampack/cache/.

CI Builds

We recommend that you save and restore folder .jampack/cache/ in your CI workflow to benefit from the cache between builds. This way, jampack will only process new images when present.

Github Actions example

This is fairly easy to do with Github Actions, using the actions/cache@v3 action:

    - uses: actions/cache@v3
        path: '.jampack'
        key: jampack-${{ github.run_id }}
        restore-keys: |
    - name: Build
      shell: bash
      run: npm run build

This is the recommended setup as at the moment there is no easy way to compute a hash for the jampack cache. This will effectively:

  • save the .jampack folder to a new cache named ‘jampack’ suffixed by the run ID, after the job runs. Do notice that you may want to have different keys if running jampack on different sites. Caches that have not been used for the longest time are evicted automatically, so this is safe
  • restore the last saved cached .jampack folder before the Build step, allowing jampack to reuse the cache


See CLI Options for options around cache management.