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LangChain · Type Alias

UsageMetadata

UsageMetadata is a standard record for token usage on a message. It includes input, output, and total token counts, plus optional token-type details.

Last updated

Since
0.3.9 for input_token_details and output_token_details

Syntax

class UsageMetadata(TypedDict):
    input_tokens: int
    output_tokens: int
    total_tokens: int
    input_token_details: NotRequired[InputTokenDetails]
    output_token_details: NotRequired[OutputTokenDetails]

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  • InputTokenDetails
  • OutputTokenDetails
  • AIMessage

Source: UsageMetadata | langchain_core | LangChain Reference. Checked 2026-11-03.