A group could be a company, team, or workspace within your app. All member of the group has access to its integrations, and only one member needs to install an integration for all members of the group to access it.
The primary key is a UID generated by a SaaS provider (e.g. Salesforce) to uniquely identify an instance of an object.
For Salesforce, it is the ID field, which is a standard field for almost all objects.
For Hubspot, each object has an ID, for example Contact has a Contact ID.
Updated 8 months ago