Custom metadata fields
OptionaldurationResponse generation duration in milliseconds
OptionalmodelAI model used for generation
OptionalfinishFinish reason for the response
OptionaltotalTotal tokens used in the conversation
OptionalinputInput/prompt tokens
OptionaloutputOutput/completion tokens
OptionalcostEstimated cost in USD
OptionalproviderAI provider (openai, anthropic, etc.)
OptionalmodelProvider-specific model version
OptionalendpointAPI endpoint used
OptionaltimestampRequest timestamp
OptionalfirstTime to first token
OptionalaverageAverage time between tokens
OptionalconfidenceResponse confidence score (0-1)
OptionalperplexityPerplexity score for language models
OptionalrelevanceRelevance score for RAG responses
Comprehensive message metadata interface Supports all AI SDK 5 metadata fields plus enterprise extensions