BerriAI/litellm · error · ValueError
Failed to transform response to Anthropic format
Error message
Failed to transform response to Anthropic format
What it means
Error "Failed to transform response to Anthropic format" thrown in BerriAI/litellm.
Source
Thrown at litellm/llms/anthropic/experimental_pass_through/adapters/handler.py:627
transformed_stream: Final = ANTHROPIC_ADAPTER.translate_completion_output_params_streaming(
completion_response,
model=model,
tool_name_mapping=tool_name_mapping,
polyfill_result=polyfill_result,
is_async=True,
)
if transformed_stream is not None:
return transformed_stream
raise ValueError("Failed to transform streaming response")
else:
anthropic_response: Final = ANTHROPIC_ADAPTER.translate_completion_output_params(
cast(ModelResponse, completion_response),
tool_name_mapping=tool_name_mapping,
polyfill_result=polyfill_result,
)
if anthropic_response is not None:
return anthropic_response
raise ValueError("Failed to transform response to Anthropic format")
@staticmethod
def anthropic_messages_handler(
max_tokens: int,
messages: _AnthropicMessages,
model: str,
metadata: dict[str, object] | None = None,
stop_sequences: list[str] | None = None,
stream: bool | None = False,
system: str | None = None,
temperature: float | None = None,
thinking: dict[str, object] | None = None,
tool_choice: dict[str, object] | None = None,
tools: list[dict[str, object]] | None = None,
top_k: int | None = None,
top_p: float | None = None,
output_format: dict[str, object] | None = None,
_is_async: bool = False,View on GitHub (pinned to 6c2dcb801b)
Solutions
- Check the upstream response format; see logs for details.
When it happens
Trigger: Thrown at litellm/llms/anthropic/experimental_pass_through/adapters/handler.py:627 when the library encounters an invalid state.
Common situations: See trigger scenarios.
AI-assisted analysis of BerriAI/litellm@6c2dcb801b (2026-08-15).
Data as JSON: /api/errors/d3bd0f4705dcdba5.
Report an issue: GitHub.