I want to know that which service I’ll use to get the Custom Fields for contacts & also for tags too.
And please provide the code snippet or just demo code with real data with the request API.
The IS API documentation covers using the data service and provides table schema for the information you are looking for. You can find api reference and examples here:
and reference to the tables you need (ContactGroup for tags and DataFormField for custom fields) here:
The “DataFormField” API table contains a list of the Custom Fields. To get a list of the Contact Custom Fields you need to search the “FormId” with the “-1” value.
As for the Tags, to get a list you need the “ContactGroup” table. For the list of assigned Tags to Contacts, you need the “ContactGroupAssign” table.