Model id for metrics

[krrishdholakia]

Relevant issues

Addresses user request for enhanced Prometheus metrics.

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Type

🆕 New Feature

Changes

WHY: Users require the model_id label in key Prometheus metrics to accurately calculate success rates and analyze performance at the specific model deployment level, enhancing observability beyond just the requested_model.

WHAT:

• Added the model_id label to the following Prometheus metrics:
  • litellm_proxy_total_requests_metric
  • litellm_proxy_failed_requests_metric
  • litellm_request_total_latency_metric
  • litellm_llm_api_time_to_first_token_metric (TTFT)
• Refactored the TTFT metric logging in litellm/integrations/prometheus.py to utilize prometheus_label_factory for consistent label handling.
• Updated Prometheus documentation (docs/my-website/docs/proxy/prometheus.md) to reflect the new labels.
• Added and updated unit tests to verify the correct inclusion of model_id in the affected metrics.

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Project	Deployment	Review	Updated (UTC)
litellm	Ready	Preview, Comment	Dec 16, 2025 10:33am

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