About the EDN data format

The KIM infrastructure embraces a subset of EDN as a standard data format. EDN stands for extensible data notation, and is pronounced like the word "eden".

The primary purpose of this data format choince is to serve as a superset to JSON notation with the enhancements being that it (1) allows for comments and (2) treats commas as whitespace enabling easier templating.

The subset of EDN allowed is constrained to:


  • nil is not allowed, this includes JSON's null which is not allowed. Instead consider (1) using an empty string ("") as the value, (2) using the number 0 as the value, (3) or omitting a key-value pair.
  • Symbols are not allowed
  • Keywords are not allowed
  • Lists are not allowed, please use vectors instead
  • Sets are not allowed
  • Tagged elements are not allowed