fix: encode bytes as base64 when dumping to json string.

Author: argaj

instrumentation-genai/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/generate_content.py

@@ -61,6 +61,7 @@
 from .dict_util import flatten_dict
 from .flags import is_content_recording_enabled
 from .message import (
+    Base64JsonEncoder,
     to_input_messages,
     to_output_messages,
     to_system_instructions,
@@ -279,7 +280,7 @@ def _create_completion_details_attributes(
         ]
 
     if as_str:
-        return {k: json.dumps(v) for k, v in attributes.items()}
+        return {k: json.dumps(v, cls=Base64JsonEncoder) for k, v in attributes.items()}
 
     return attributes
 

instrumentation-genai/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/message.py

@@ -14,8 +14,11 @@
 
 from __future__ import annotations
 
+from base64 import b64encode
+import json
 import logging
 from enum import Enum
+from typing import Any
 
 from google.genai import types as genai_types
 from opentelemetry.util.genai.types import (
@@ -38,6 +41,13 @@ class Role(str, Enum):
     TOOL = "tool"
 
 
+class Base64JsonEncoder(json.JSONEncoder):
+    def default(self, o: Any) -> Any:
+        if isinstance(o, bytes):
+            return b64encode(o).decode()
+        return super().default(o)
+
+
 _logger = logging.getLogger(__name__)