DocumentDB REST API: x-ms-documentdb-partitionkey is invalid

Question

I am attempted to get a Document from DocumentDB using the REST API. I am using a partitioned Collection and therefore need to add the "x-ms-documentdb-partitionkey" header. If I add this, I get "Partition key abc is invalid". I can't find anywhere in the documentation that expects the key to be in specific format, but simply supplying the expected string value does not work. Does anyone know the expected format?

Answer 1

Partition key must be specified as an array (with a single element). For example:

x-ms-documentdb-partitionkey: [ "abc" ]