When a document is mutated, it would be very handy to be able to audit what caused the mutation to happen. However, the oplog doesn't currently include much client context.

Ideally, clients could add some context, eg:

db.runCommand({
  insert: mycoll,
  documents: [{_id: "myid"}],
  oplogContext: {"some": "document}
})

And then this context could appear in the oplog:

{
  "ts": Timestamp(1585854690, 1),
  "t": NumberLong(1),
  ...
  "context": {"some": "document}
}