fix: route RequestBodyPlainText to request_body_data instead of request_body_json

This fixes a bug where RequestBodyPlainText was incorrectly routed to
request_body_json, causing ValueError: 'Request body json cannot be a string'
when using Plain Text body in the Connector Builder.

The fix routes RequestBodyPlainText to request_body_data (like
RequestBodyUrlEncodedForm) instead of request_body_json.

Fixes: airbytehq/oncall#10360
Related: airbytehq/airbyte#69723
Co-Authored-By: unknown <>

Author: devin-ai-integration[bot]

airbyte_cdk/sources/declarative/requesters/request_options/interpolated_request_options_provider.py

@@ -99,9 +99,11 @@ def _resolve_request_body(self) -> None:
         if self.request_body is not None and self.request_body.type is not None:
             if self.request_body.type == "RequestBodyUrlEncodedForm":
                 self.request_body_data = self.request_body.value
+            elif self.request_body.type == "RequestBodyPlainText":
+                self.request_body_data = self.request_body.value
             elif self.request_body.type == "RequestBodyGraphQL":
                 self.request_body_json = self.request_body.value.dict(exclude_none=True)
-            elif self.request_body.type in ("RequestBodyJsonObject", "RequestBodyPlainText"):
+            elif self.request_body.type == "RequestBodyJsonObject":
                 self.request_body_json = self.request_body.value
             else:
                 raise ValueError(f"Unsupported request body type: {self.request_body.type}")