Custom language runtimes

You can build a custom language runtime with the language, packages, and platforms you need.

Customizing language builds is an in-progress, beta feature. We’re working hard on adding packages and optimizing the build experience. We recommend that you start with a small number of packages on your preferred operating system. Once your project builds successfully, you can experiment with additional options.

To create a new custom runtime project:

  1. Open your web browser and navigate to and sign in.
  2. On the Your Dashboard page, click Set up a new Runtime.
  3. In Choose a language, select Python, Perl, or Tcl as your runtime language.
  4. Select Build your own.
  5. Enter a short, meaningful name for the project in Name your runtime.
  6. Select the version for your language runtime.
  7. In the Choose your operating systems section, click the checkbox next to the platform(s) to include and select the version that matches the operating system you will use the language runtime on.
  8. Runtime projects are public by default. If you belong to a paid account, you can choose to make your runtime private. Access to private projects is restricted to users that belong to the organization the private project is associated with.
  9. Click Create Runtime.

To add packages to your new project:

  1. Click Choose Packages to customize the packages included in your build.
  2. In the Add Packages dialog box, type in part of a package name and click Search.
  3. Click Add next to the package name to add a package from the search results.
  4. Repeat steps 2 and 3 to add additional packages, and click Done when you are finished adding packages.
  5. Click Commit Changes. This is the step that starts the build in our server farm. The time it takes for the build to complete depends on the complexity of the build and the available resources to complete the build.
  6. Click View Status. If the build status is In Progress, you can come back later to verify that the build completed successfully. In some cases, the build will fail immediately and you may need to adjust your settings and try again.
  7. Once your build completes successfully, you can download the installer from the Download Builds tab or use the commands listed on the Overview page to activate your project using the State Tool.

If you have additional existing projects that you want to add, you can create them by exporting the requirements from your existing Python environment using the pip freeze command and then importing them to your Platform project. For more information on this process, see Creating projects from requirements.txt files.