From 4ed73438f00eac2b47c288eda1be658bd7bbd202 Mon Sep 17 00:00:00 2001
From: Derek Allan Boman <derekboman3@gmail.com>
Date: Mon, 27 Jul 2026 18:48:21 -0700
Subject: [PATCH] Fix JSON serialization in async HTTP client

---
 tests/unit/http/test_async_http_client.py | 30 +++++++++++++++++++++++
 twilio/http/async_http_client.py          |  8 +++++-
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/tests/unit/http/test_async_http_client.py b/tests/unit/http/test_async_http_client.py
index 23df35dc02..05c71fa57f 100644
--- a/tests/unit/http/test_async_http_client.py
+++ b/tests/unit/http/test_async_http_client.py
@@ -43,6 +43,36 @@ async def test_request_called_with_method_and_url(self):
         self.assertEqual(request_args["method"], "GET")
         self.assertEqual(request_args["url"], "https://mock.twilio.com")
 
+    async def test_request_body_is_passed_as_json_for_application_json(self):
+        body = {"userName": "Alice"}
+
+        await self.client.request(
+            "POST",
+            "https://mock.twilio.com",
+            data=body,
+            headers={"Content-Type": "application/json"},
+        )
+
+        request_args = self.session_mock.request.call_args.kwargs
+
+        self.assertEqual(request_args["json"], body)
+        self.assertNotIn("data", request_args)
+
+    async def test_request_body_is_passed_as_json_for_scim_json(self):
+        body = {"userName": "Alice"}
+
+        await self.client.request(
+            "POST",
+            "https://mock.twilio.com",
+            data=body,
+            headers={"Content-Type": "application/scim+json"},
+        )
+
+        request_args = self.session_mock.request.call_args.kwargs
+
+        self.assertEqual(request_args["json"], body)
+        self.assertNotIn("data", request_args)
+        
     async def test_request_called_with_basic_auth(self):
         await self.client.request(
             "doesnt matter", "doesnt matter", auth=("account_sid", "auth_token")
diff --git a/twilio/http/async_http_client.py b/twilio/http/async_http_client.py
index ecd5d4de95..2a0f1c00f6 100644
--- a/twilio/http/async_http_client.py
+++ b/twilio/http/async_http_client.py
@@ -87,13 +87,19 @@ async def request(
             "method": method.upper(),
             "url": url,
             "params": params,
-            "data": data,
             "headers": headers,
             "auth": basic_auth,
             "timeout": timeout,
             "allow_redirects": allow_redirects,
         }
 
+        content_type = (headers or {}).get("Content-Type", "").lower()
+
+        if content_type in ("application/json", "application/scim+json"):
+            kwargs["json"] = data
+        else:
+            kwargs["data"] = data
+
         self.log_request(kwargs)
         self._test_only_last_response = None