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Request Headers

Special headers that are supported by LiteLLM.

Header Forwarding​

By default, LiteLLM does not forward client headers to LLM provider APIs. However, you can selectively enable header forwarding for specific model groups. Learn more about configuring header forwarding.

LiteLLM Headers​

x-litellm-timeout Optional[float]: The timeout for the request in seconds.

x-litellm-stream-timeout Optional[float]: The timeout for getting the first chunk of the response in seconds (only applies for streaming requests). Demo Video

x-litellm-enable-message-redaction: Optional[bool]: Don't log the message content to logging integrations. Just track spend. Learn More

x-litellm-tags: Optional[str]: A comma separated list (e.g. tag1,tag2,tag3) of tags to use for tag-based routing OR spend-tracking.

x-litellm-num-retries: Optional[int]: The number of retries for the request.

x-litellm-spend-logs-metadata: Optional[str]: JSON string containing custom metadata to include in spend logs. Example: {"user_id": "12345", "project_id": "proj_abc", "request_type": "chat_completion"}. Learn More

Anthropic Headers​

anthropic-version Optional[str]: The version of the Anthropic API to use.
anthropic-beta Optional[str]: The beta version of the Anthropic API to use.

  • For /v1/messages endpoint, this will always be forward the header to the underlying model.
  • For /chat/completions endpoint, this will only be forwarded if the model is configured in forward_client_headers_to_llm_api. Learn more

OpenAI Headers​

openai-organization Optional[str]: The organization to use for the OpenAI API. (currently needs to be enabled via general_settings::forward_openai_org_id: true)

Custom Headers​

Custom headers starting with x- can be forwarded to LLM provider APIs when the model is configured in forward_client_headers_to_llm_api. Learn more about header forwarding configuration.