> ## Documentation Index
> Fetch the complete documentation index at: https://docs.seam.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Developing Your Visionline Plastic Card Encoding App Using a Sandbox Workspace

> Learn how to use Seam's virtual Visionline ACS to develop your Visionline plastic card encoding app.

If you do not have access to an unlicensed Visionline account, you can use a [sandbox workspace](/core-concepts/workspaces#sandbox-workspaces) and Seam-provided virtual Visionline ACS to develop and test your Visionline plastic card encoding app. Seam sandbox workspaces provide test accounts and virtual devices and systems that you can connect and control. Importantly, virtual devices and systems behave identically to the corresponding real devices and systems.

For detailed instructions, see the following topics:

1. [Step 1: Create a Sandbox Workspace](./step-1-create-a-sandbox-workspace)
2. [Step 2: Connect the Virtual Visionline ACS to Seam](./step-2-connect-the-virtual-visionline-acs-to-seam)
3. [Next Steps](./next-steps)