Schema.ai· vLLM
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In vLLM v0.23.0, vllm:time_to_first_token_seconds is registered as a Prometheus histogram.

MetricvLLM v0.23.0confidence: highverified 1 hr agoverified-code

Metric

time_to_first_token_seconds

Applies when

PrometheusStatLogger metrics publisherV1 metrics

Evidence

vLLM v0.23.0 v1 metrics loggers.py(vllm/v1/metrics/loggers.py:754-782)
definesprimarysource_codecode_introspection

Does not establish

  • the metric's unit of measure
  • what the metric measures semantically
  • a healthy or expected value range

Guards

  • vllm_version = v0.23.0
  • metric_name = vllm:time_to_first_token_seconds

Freshness

Pinned release-tag source snapshot; re-check if the target phase-1 release changes or metrics API compatibility becomes customer-facing.