From b6784e7d8c2e4e4dd22958a933cd6d624344d119 Mon Sep 17 00:00:00 2001
From: Chesars <cesarponce19544@gmail.com>
Date: Thu, 26 Feb 2026 16:13:23 -0300
Subject: [PATCH] fix(types): annotate _FINISH_REASON_MAP and map_finish_reason
 with OpenAIChatCompletionFinishReason

Fixes mypy errors where dict[str, str] was incompatible with the
expected Literal type in get_finish_reason_mapping() and
_check_finish_reason() return types.
---
 litellm/litellm_core_utils/core_helpers.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/litellm/litellm_core_utils/core_helpers.py b/litellm/litellm_core_utils/core_helpers.py
index 5dad19f2599..ee111f35929 100644
--- a/litellm/litellm_core_utils/core_helpers.py
+++ b/litellm/litellm_core_utils/core_helpers.py
@@ -5,7 +5,7 @@ from typing import TYPE_CHECKING, Any, Iterable, List, Literal, Optional, Union
 import httpx
 
 from litellm._logging import verbose_logger
-from litellm.types.llms.openai import AllMessageValues
+from litellm.types.llms.openai import AllMessageValues, OpenAIChatCompletionFinishReason
 
 if TYPE_CHECKING:
     from opentelemetry.trace import Span as _Span
@@ -58,7 +58,7 @@ def safe_divide(
     return numerator / denominator
 
 
-_FINISH_REASON_MAP = {
+_FINISH_REASON_MAP: dict[str, OpenAIChatCompletionFinishReason] = {
     # Anthropic
     "stop_sequence": "stop",
     "end_turn": "stop",
@@ -99,7 +99,7 @@ _FINISH_REASON_MAP = {
 }
 
 
-def map_finish_reason(finish_reason: str) -> str:
+def map_finish_reason(finish_reason: str) -> OpenAIChatCompletionFinishReason:
     mapped = _FINISH_REASON_MAP.get(finish_reason)
     if mapped is None:
         verbose_logger.warning(