Understanding Flex Credit consumption

Hi everyone,   

I’m looking for some clarity and real-world experience around Flex Credit consumption, particularly related to Einstein summaries and Prompt Builder.   

We currently have 3,000,000 Flex Credits as part of our Salesforce contract, and we’ve already consumed over 50% of them, with around 1,450,000 credits remaining. This level of consumption is happening much faster than we expected, and it’s not very clear to us what exactly is driving the usage. our contract is till Sept 2028   

At the moment, we’re struggling to find detailed diagnostics within Salesforce that explain where and how these credits are being used.

Specifically, I’m hoping the community can help with the following:

1. Is there a native way to view a detailed breakdown of Flex Credit usage, for example by feature, prompt, automation, or Prompt Builder?
2. How are Flex Credits typically consumed for Einstein-generated summaries? we use Einstin to summarize our inbound and outbount ticket calls. 
   • Is usage calculated per summary generated?
   • Does transcript length or prompt complexity affect consumption?
3. Do automatic or programmatic summaries consume Flex Credits differently compared to user-initiated summaries?
4. Are Flex Credits allocated for the entire contract duration, or do they reset annually?
5. For customers using Einstein summaries at scale, what would be considered a normal or expected burn rate?

We want to ensure we’re using Einstein and Prompt Builder efficiently and architecting this correctly, rather than over-consuming credits unnecessarily.   

Any insights, best practices, or lessons learned would be greatly appreciated.

Thanks in advance!