From f1c33c4d1c2c9253b1e2b7172e411f25357887c8 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Wed, 27 May 2026 00:45:29 +0000
Subject: [PATCH] fix(mcp): set sequence_number on mcp_call output_item.done
 event

create_mcp_call_events relied on OutputItemDoneEvent's default
sequence_number, which was previously 1 but is now 0. Pass an
explicit value so the event matches the streaming sequence order
emitted by the surrounding MCP call events.
---
 litellm/responses/mcp/mcp_streaming_iterator.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/litellm/responses/mcp/mcp_streaming_iterator.py b/litellm/responses/mcp/mcp_streaming_iterator.py
index 42c46dff47c..246caa584cd 100644
--- a/litellm/responses/mcp/mcp_streaming_iterator.py
+++ b/litellm/responses/mcp/mcp_streaming_iterator.py
@@ -218,6 +218,7 @@ def create_mcp_call_events(
         output_item_done_event = OutputItemDoneEvent(
             type=ResponsesAPIStreamEvents.OUTPUT_ITEM_DONE,
             output_index=0,
+            sequence_number=sequence_start + 4,
             item=BaseLiteLLMOpenAIResponseObject(
                 **{
                     "id": item_id,