Does Calculus AI access actual data in the CRM while responding to a query?  

Yes, for queries that are based on CRM data, Calculus AI looks at existing data in the CRM. Calculus AL will generate a better response for these queries with this data.
For example, when prompted to get the Case or Chat Summary, Calculus AI will access the conversation text in the Case or Chat.  
Custom-trained or fine-tuned models must be developed for some queries. Here are examples for which the AI needs custom training:

• Write a sales pitch for John based on the data available in Contacts. 
  • What parameters in the Contact should Calculus AI look at other than name and email? 
  • Should it look at the city to match products? 
  • Should it look at related products, etc? 
• Write me a summary of the conversation in case# CC123456.

Note: Vtiger offers professional services to build custom models.