Yes, copying from existing integration assemblies is basically how we always start a new integration.
The main trick is having an understanding of which existing integration most closely matches the new one, mainly in terms of authorization. Takes some time to review the existing integrations in the catalog.
The most common pattern in terms of auth for major API providers is OAuth. API keys are otherwise most common. This page provides an overview of the various types of common auth:
Action and triggers also have various patterns:
These decision tree flowcharts can also help guide you based on known integration patterns: