Stream Metrics • Rust AI Agent SDK

StreamMetrics: Timing metrics for a streaming response.

StreamMetrics

Defined in the streaming module.

Rust AI Agent SDK

Timing metrics for a streaming response.

Name	Type	Description
`request_start`	`u64`	Request start time (ms)
`headers_received`	`u64`	Headers received time (ms)
`first_token`	`u64`	First token time (ms)
`last_token`	`u64`	Last token time (ms)
`stream_end`	`u64`	Stream end time (ms)
`token_count`	`usize`	Token count
`start_instant`	`Option<Instant>`	Internal start instant for precise timing

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fn new() -> Self

Create new metrics

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fn ttft_ms(&self) -> u64

Time To First Token in milliseconds

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fn stream_duration_ms(&self) -> u64

Stream duration in milliseconds

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fn total_time_ms(&self) -> u64

Total time in milliseconds

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fn tokens_per_second(&self) -> f64

Tokens per second

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fn update_from_event(&mut self, event: &StreamEvent) -> ()

Update metrics from a stream event

Parameters:

Name	Type
`event`	`&StreamEvent`

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fn mark_request_start(&mut self) -> ()

Mark request start

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fn mark_first_token(&mut self) -> ()

Mark first token

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fn mark_last_token(&mut self) -> ()

Mark last token

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fn mark_stream_end(&mut self) -> ()

Mark stream end

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fn increment_tokens(&mut self) -> ()

Increment token count

praisonai/src/streaming/mod.rs at line 242