I have an RE query that returns gift and constituent data. Is there an API endpoint to execute this query and retrieve the results? I can't find one that looks appropriate on the endpoint reference page
There is Query API endpoint that does what you want.
Execute Query by saved query id
Execute Ad-hoc Query by dynamic JSON definition
Get Query execution job status (used periodically, every 30 seconds, to see if query completed execution yet.
There are many template that was published that you can use to get started.
Thank you!