The following is a summary of various API ingress and egress concepts supported by the Appsheet platform, with links to additional help articles as needed.
AppSheet has a full stack Rest API for inbound connections to any particular app.
You can learn more about the Rest API here. The basic verbs are: Add, Delete, Edit (update), Find, or Invoke Action (where action is a defined action in the app).
The general nature of the AppSheet Rest API is to provide CRUD support at the transactional level for the table to which you are connecting with your API client.
Webhooks inside of an AppSheet workflow
The basic verbs are Delete, Patch, Post and Put. There is no return nor expectation of one by design. A variety of API body payloads and header configurations are supported.
Note: currently there is no multipart file upload (e.g. base64 image) mime type support.
Direct connect to oData protocol
AppSheet can directly connect to oData sources. If your Rest API is represented as an oData feed this is a zero effort experience. You can learn more here.
Direct connect to external Rest API (Apigee)
AppSheet can connect to Rest API endpoints which meet certain requirements, e.g. can be represented as an OpenAPI Spec (swagger) or can be exposed in such a way that they are one or more rectangular or tabular data sources. More information is available here