From 33f4411f17b73e62332ff658ebadcb9579b99783 Mon Sep 17 00:00:00 2001
From: Joe Cheng <joe@posit.co>
Date: Fri, 2 Aug 2024 13:05:23 -0700
Subject: [PATCH] Fix tool call coalescing

The previous code seemed to assume that the tool call index property
started at 0, but Anthropic sometimes returns them starting at 1.
This was causing an extra null-ish tool call to be materialized.
---
 litellm/main.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/litellm/main.py b/litellm/main.py
index 989e0b11063..36267aec1d6 100644
--- a/litellm/main.py
+++ b/litellm/main.py
@@ -5094,7 +5094,7 @@ def stream_chunk_builder(
         name = None
         type = None
         tool_calls_list = []
-        prev_index = 0
+        prev_index = None
         prev_id = None
         curr_id = None
         curr_index = 0
@@ -5120,6 +5120,8 @@ def stream_chunk_builder(
                         name = tool_calls[0].function.name
                     if tool_calls[0].type:
                         type = tool_calls[0].type
+            if prev_index is None:
+                prev_index = curr_index
             if curr_index != prev_index:  # new tool call
                 combined_arguments = "".join(argument_list)
                 tool_calls_list.append(
@@ -5138,6 +5140,7 @@ def stream_chunk_builder(
         tool_calls_list.append(
             {
                 "id": id,
+                "index": curr_index,
                 "function": {"arguments": combined_arguments, "name": name},
                 "type": type,
             }