diff --git a/src/connections/functions/source-functions.md b/src/connections/functions/source-functions.md index 646db8e948..d9513df49d 100644 --- a/src/connections/functions/source-functions.md +++ b/src/connections/functions/source-functions.md @@ -438,3 +438,9 @@ The test function interface has a 4KB console logging limit. Outputs surpassing #### Can I send a custom response from my Source Function to an external tool? No, Source Functions can't send custom responses to the tool that triggered the Function's webhook. Source Functions can only send a success or failure response, not a custom one. + +#### Why am I seeing the error "Functions are unable to send data or events back to their originating source" when trying to save my Source Function? + +This error occurs because Segment prevents Source Functions from sending data back to their own webhook endpoint (`https://fn.segmentapis.com`). Allowing this could create an infinite loop where the function continuously triggers itself. + +To resolve this error, check your Function code and ensure the URL `https://fn.segmentapis.com` is not included. This URL is used to send data to a Source Function and shouldn't appear in your outgoing requests. Once you remove this URL from your code, you’ll be able to save the Function successfully.