CRaC Engine can support storing additional metadata about the image. This can help the infrastructure to further refine the set of feasible images (constrained by CPU architecture and features) and select the image that is expected to perform best.

In this first phase this API can be internal-only, publishing parameters such as:
- number of CPU cores used during checkpoint run
- heap memory size
- number of loaded classes
- number of C1/C2 compilations
- timestamps (boot time, checkpoint time...)

In the future we will expose the API to the users, allowing them to record application-defined metrics (e.g. average time needed to handle certain request, size of application-level cache...).