Revert "fix(embedding): omit null encoding_format for openai requests (#25395)"

This reverts commit e3d160f158.

litellm/main.py

@@ -4913,6 +4913,9 @@ def embedding(  # noqa: PLR0915
 
             if encoding_format is not None:
                 optional_params["encoding_format"] = encoding_format
+            else:
+                # Omiting causes openai sdk to add default value of "float"
+                optional_params["encoding_format"] = None
 
             api_version = None
 

tests/test_litellm/llms/openai/embeddings/test_openai_embeddings_encoding_format.py

@@ -1,34 +0,0 @@
-from unittest.mock import patch
-
-import litellm
-
-
-@patch("litellm.main.openai_chat_completions.embedding", return_value={"ok": True})
-def test_openai_embedding_does_not_send_encoding_format_when_unset(mock_embedding):
-    """Regression test: do not send encoding_format=null to OpenAI-compatible APIs."""
-    litellm.embedding(
-        model="text-embedding-3-small",
-        input=["hello"],
-        api_base="https://example.com/v1",
-        api_key="test-key",
-        custom_llm_provider="openai",
-    )
-
-    optional_params = mock_embedding.call_args.kwargs["optional_params"]
-    assert "encoding_format" not in optional_params
-
-
-@patch("litellm.main.openai_chat_completions.embedding", return_value={"ok": True})
-def test_openai_embedding_preserves_explicit_encoding_format(mock_embedding):
-    """Explicit encoding_format should still be forwarded."""
-    litellm.embedding(
-        model="text-embedding-3-small",
-        input=["hello"],
-        api_base="https://example.com/v1",
-        api_key="test-key",
-        custom_llm_provider="openai",
-        encoding_format="float",
-    )
-
-    optional_params = mock_embedding.call_args.kwargs["optional_params"]
-    assert optional_params["encoding_format"] == "float"