fix: use urllib.parse.urlencode in realtime_tts and conversation URLs

Apply the same urlencode fix to the remaining manual query string
construction sites in realtime_tts.py and conversation.py.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kraenhansen

src/elevenlabs/conversational_ai/conversation.py

@@ -430,10 +430,14 @@ def _get_wss_url(self):
         # Ensure base URL ends with '/' for proper joining
         if not base_ws_url.endswith("/"):
             base_ws_url += "/"
-        url = f"{base_ws_url}v1/convai/conversation?agent_id={self.agent_id}&source=python_sdk&version={__version__}"
+        params: list[tuple[str, str]] = [
+            ("agent_id", self.agent_id),
+            ("source", "python_sdk"),
+            ("version", __version__),
+        ]
         if self.environment:
-            url += f"&environment={self.environment}"
-        return url
+            params.append(("environment", self.environment))
+        return f"{base_ws_url}v1/convai/conversation?{urllib.parse.urlencode(params)}"
 
     def _get_signed_url(self):
         response = self.client.conversational_ai.conversations.get_signed_url(
@@ -442,8 +446,10 @@ def _get_signed_url(self):
         )
         signed_url = response.signed_url
         # Append source and version query parameters to the signed URL
-        separator = "&" if "?" in signed_url else "?"
-        return f"{signed_url}{separator}source=python_sdk&version={__version__}"
+        parsed = urllib.parse.urlparse(signed_url)
+        existing_params = urllib.parse.parse_qsl(parsed.query)
+        existing_params.extend([("source", "python_sdk"), ("version", __version__)])
+        return urllib.parse.urlunparse(parsed._replace(query=urllib.parse.urlencode(existing_params)))
 
     def _create_on_prem_initiation_message(self):
         return json.dumps(

src/elevenlabs/realtime_tts.py

@@ -94,7 +94,7 @@ def get_text() -> typing.Iterator[str]:
         with connect(
             urllib.parse.urljoin(
               self._ws_base_url,
-              f"v1/text-to-speech/{jsonable_encoder(voice_id)}/stream-input?model_id={model_id}&output_format={output_format}"
+              f"v1/text-to-speech/{jsonable_encoder(voice_id)}/stream-input?{urllib.parse.urlencode({"model_id": model_id, "output_format": output_format})}"
             ),
             additional_headers=jsonable_encoder(
                 remove_none_from_dict(