PostGrid PostGrid is a direct mail automation platform. It allows businesses to create, print, and mail physical marketing materials programmatically. Developers can use its API to integrate direct mail capabilities into their applications. Official docs: https://www.postgrid.com/docs/ PostGrid Overview - Postcard - Template - Letter - Template - Address - Batch - Job - Tracking - Webhook Working with PostGrid This skill uses the Membrane CLI to interact with PostGrid. Membrane handles authentication and credentials refresh automatically — so you can focus on the integration logic rather than…