UsageMetadata#

class langchain_core.messages.ai.UsageMetadata[source]#

Usage metadata for a message, such as token counts.

This is a standard representation of token usage that is consistent across models.

Example

{
    "input_tokens": 350,
    "output_tokens": 240,
    "total_tokens": 590,
    "input_token_details": {
        "audio": 10,
        "cache_creation": 200,
        "cache_read": 100,
    },
    "output_token_details": {
        "audio": 10,
        "reasoning": 200,
    }
}

Changed in version 0.3.9: Added input_token_details and output_token_details.

input_tokens: int#: Count of input (or prompt) tokens. Sum of all input token types.

output_tokens: int#: Count of output (or completion) tokens. Sum of all output token types.

total_tokens: int#: Total token count. Sum of input_tokens + output_tokens.

input_token_details: NotRequired[InputTokenDetails]#

Breakdown of input token counts.

Does not need to sum to full input token count. Does not need to have all keys.

output_token_details: NotRequired[OutputTokenDetails]#

Breakdown of output token counts.

Does not need to sum to full output token count. Does not need to have all keys.