feat(ai): add parse_data_uri function to parse a data URI (#5311)

Add a central function to parse data URIs to be used in AI integrations
where Blob data is usually sent as data URIs

Author: constantinius

sentry_sdk/ai/utils.py

@@ -40,6 +40,38 @@ class GEN_AI_ALLOWED_MESSAGE_ROLES:
         GEN_AI_MESSAGE_ROLE_MAPPING[source_role] = target_role
 
 
+def parse_data_uri(url: str) -> "Tuple[str, str]":
+    """
+    Parse a data URI and return (mime_type, content).
+
+    Data URI format (RFC 2397): data:[<mediatype>][;base64],<data>
+
+    Examples:
+        data:image/jpeg;base64,/9j/4AAQ... → ("image/jpeg", "/9j/4AAQ...")
+        data:text/plain,Hello → ("text/plain", "Hello")
+        data:;base64,SGVsbG8= → ("", "SGVsbG8=")
+
+    Raises:
+        ValueError: If the URL is not a valid data URI (missing comma separator)
+    """
+    if "," not in url:
+        raise ValueError("Invalid data URI: missing comma separator")
+
+    header, content = url.split(",", 1)
+
+    # Extract mime type from header
+    # Format: "data:<mime>[;param1][;param2]..." e.g. "data:image/jpeg;base64"
+    # Remove "data:" prefix, then take everything before the first semicolon
+    if header.startswith("data:"):
+        mime_part = header[5:]  # Remove "data:" prefix
+    else:
+        mime_part = header
+
+    mime_type = mime_part.split(";")[0]
+
+    return mime_type, content
+
+
 def _normalize_data(data: "Any", unpack: bool = True) -> "Any":
     # convert pydantic data (e.g. OpenAI v1+) to json compatible format
     if hasattr(data, "model_dump"):

tests/test_ai_monitoring.py

@@ -17,6 +17,7 @@
     truncate_and_annotate_messages,
     truncate_messages_by_size,
     _find_truncation_index,
+    parse_data_uri,
     redact_blob_message_parts,
 )
 from sentry_sdk.serializer import serialize
@@ -757,3 +758,87 @@ def test_handles_non_dict_content_items(self):
 
         # Should return same list since no blobs
         assert result is messages
+
+
+class TestParseDataUri:
+    def test_parses_base64_image_data_uri(self):
+        """Test parsing a standard base64-encoded image data URI"""
+        uri = "data:image/jpeg;base64,/9j/4AAQSkZJRg=="
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == "image/jpeg"
+        assert content == "/9j/4AAQSkZJRg=="
+
+    def test_parses_png_data_uri(self):
+        """Test parsing a PNG image data URI"""
+        uri = "data:image/png;base64,iVBORw0KGgo="
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == "image/png"
+        assert content == "iVBORw0KGgo="
+
+    def test_parses_plain_text_data_uri(self):
+        """Test parsing a plain text data URI without base64 encoding"""
+        uri = "data:text/plain,Hello World"
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == "text/plain"
+        assert content == "Hello World"
+
+    def test_parses_data_uri_with_empty_mime_type(self):
+        """Test parsing a data URI with empty mime type"""
+        uri = "data:;base64,SGVsbG8="
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == ""
+        assert content == "SGVsbG8="
+
+    def test_parses_data_uri_with_only_data_prefix(self):
+        """Test parsing a data URI with only the data: prefix and content"""
+        uri = "data:,Hello"
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == ""
+        assert content == "Hello"
+
+    def test_raises_on_missing_comma(self):
+        """Test that ValueError is raised when comma separator is missing"""
+        with pytest.raises(ValueError, match="missing comma separator"):
+            parse_data_uri("data:image/jpeg;base64")
+
+    def test_raises_on_empty_string(self):
+        """Test that ValueError is raised for empty string"""
+        with pytest.raises(ValueError, match="missing comma separator"):
+            parse_data_uri("")
+
+    def test_handles_content_with_commas(self):
+        """Test that only the first comma is used as separator"""
+        uri = "data:text/plain,Hello,World,With,Commas"
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == "text/plain"
+        assert content == "Hello,World,With,Commas"
+
+    def test_parses_data_uri_with_multiple_parameters(self):
+        """Test parsing a data URI with multiple parameters in header"""
+        uri = "data:text/plain;charset=utf-8;base64,SGVsbG8="
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == "text/plain"
+        assert content == "SGVsbG8="
+
+    def test_parses_audio_data_uri(self):
+        """Test parsing an audio data URI"""
+        uri = "data:audio/wav;base64,UklGRiQA"
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == "audio/wav"
+        assert content == "UklGRiQA"
+
+    def test_handles_uri_without_data_prefix(self):
+        """Test parsing a URI that doesn't have the data: prefix"""
+        uri = "image/jpeg;base64,/9j/4AAQ"
+        mime_type, content = parse_data_uri(uri)
+
+        assert mime_type == "image/jpeg"
+        assert content == "/9j/4AAQ"