Add support for configuring Splunk sourcetype in Custom Destinations (#3164)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

Author: api-clients-generation-pipeline[bot]

.generator/schemas/v2/openapi.yaml

@@ -18216,6 +18216,16 @@ components:
             Must have HTTPS scheme and forwarding back to Datadog is not allowed.
           example: https://example.com
           type: string
+        sourcetype:
+          description: |-
+            The Splunk sourcetype for the events sent to this Splunk destination.
+
+            If absent, the default sourcetype `_json` is used. If set to null, the `sourcetype`
+            field is omitted from the Splunk HEC payload entirely. Otherwise, the provided string
+            value is used as the sourcetype.
+          example: my-source
+          nullable: true
+          type: string
         type:
           $ref: "#/components/schemas/CustomDestinationForwardDestinationSplunkType"
       required:
@@ -18491,6 +18501,16 @@ components:
             Must have HTTPS scheme and forwarding back to Datadog is not allowed.
           example: https://example.com
           type: string
+        sourcetype:
+          description: |-
+            The Splunk sourcetype for the events sent to this Splunk destination.
+
+            If absent, the default sourcetype `_json` is used. If set to null, the `sourcetype`
+            field is omitted from the Splunk HEC payload entirely. Otherwise, the provided string
+            value is used as the sourcetype.
+          example: my-source
+          nullable: true
+          type: string
         type:
           $ref: "#/components/schemas/CustomDestinationResponseForwardDestinationSplunkType"
       required:

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-a-null-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:47.455Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-a-null-sourcetype-returns-OK-response.yml

@@ -0,0 +1 @@
+2026-03-25T16:23:49.008Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-a-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:50.210Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-a-sourcetype-returns-OK-response.yml

@@ -0,0 +1 @@
+2026-03-25T16:23:51.766Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-an-empty-string-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:52.120Z