Using Pip Packages

LiteLambda supports almost any third-party Python library available on PyPI. We cache your dependencies to ensure blazing fast cold starts.

Adding Packages

To use external libraries, you must explicitly declare them in your job's configuration. In the dashboard, navigate to your Cron Job and open the Packages tab.

List your packages exactly as you would in a standard requirements.txt file. We highly recommend pinning exact versions to prevent your job from breaking unexpectedly due to a upstream library update.

# Good practice (pinned version)
requests==2.31.0
beautifulsoup4==4.12.2

# Acceptable, but risky for production
pandas

The Build Process

When you update your package list and click Save, LiteLambda kicks off an asynchronous background build process. We download the requested wheels, uncompress them, and store them in a dedicated layer cache for your specific job.

During execution, this pre-built layer is mounted directly into your sandbox container, allowing imports to resolve instantly.

Note: Package builds typically take 10-30 seconds depending on size. You will see the package status change to "Ready" in the UI when the build is complete. If a cron execution triggers while packages are still building, it will run without the new packages.

Limitations

  • Size Limit: Individual packages cannot exceed 10 MB compressed (wheel size). Packages like tensorflow or pytorch are not supported.
  • C-Extensions: Packages that require complex system-level C dependencies during installation may fail to build. Standard pre-compiled manylinux wheels will work perfectly.