We can add custom user given metadata in AWS S3 as part of S3Headers in S3 Producer. However, the same user provided meta data cannot be retrieved via S3 Consumer.
Amazon SDK S3 Object provides two types of meta data:
1) Raw Meta Data
2) User Meta Data
In S3Endpoint.java, you can either set User Meta Data instead of Raw Meta Data for S3 Headers or provide another key like S3UserMetaData and provide this User Meta Data as value for that key.
Currently, there seems to be no way to access this User provided custom headers using Camel.