From ac679561f534125538f2cd1ed86cbb2970828e56 Mon Sep 17 00:00:00 2001
From: Mateo Wang <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 24 Jun 2026 08:06:27 -0700
Subject: [PATCH] fix(anthropic): skip content-less keepalive chunks in
 streaming bridge

A chunk with empty choices and no usage carries no content, billing, or
finish reason, so translating it emitted a premature message_delta and
broke Anthropic SSE ordering. Skip such keepalives in both the sync and
async iterator loops; usage-only trailing chunks (choices=[] with usage)
still flow through.
---
 .../adapters/streaming_iterator.py                          | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/litellm/llms/anthropic/experimental_pass_through/adapters/streaming_iterator.py b/litellm/llms/anthropic/experimental_pass_through/adapters/streaming_iterator.py
index 3aec95f5c02..ddb6e7b7021 100644
--- a/litellm/llms/anthropic/experimental_pass_through/adapters/streaming_iterator.py
+++ b/litellm/llms/anthropic/experimental_pass_through/adapters/streaming_iterator.py
@@ -388,6 +388,9 @@ class AnthropicStreamWrapper(AdapterCompletionStreamWrapper):
                 if chunk == "None" or chunk is None:
                     raise Exception
 
+                if not chunk.choices and getattr(chunk, "usage", None) is None:
+                    continue
+
                 should_start_new_block = self._should_start_new_content_block(chunk)
                 if should_start_new_block:
                     self._increment_content_block_index()
@@ -609,6 +612,9 @@ class AnthropicStreamWrapper(AdapterCompletionStreamWrapper):
                 if chunk == "None" or chunk is None:
                     raise Exception
 
+                if not chunk.choices and getattr(chunk, "usage", None) is None:
+                    continue
+
                 # Check if we need to start a new content block
                 should_start_new_block = self._should_start_new_content_block(chunk)
                 if should_start_new_block: