Every record needs one unique primitive key
The key pointer is resolved inside every item. Missing, object-valued, array-valued, or duplicate keys fail explicitly so records are never paired ambiguously.
Each document is capped at 512 KiB, combined input at 1 MiB, traversal at 100,000 values and 100 levels, reports at 10,000 entries, and output at 1 MiB. Source and results stay in the active browser tab.