AI Gateway Metrics Rename — v0.136

Metric names in AI Gateway are being renamed. A dual-write transition period lets you migrate dashboards and alerts without downtime.

Applicable to: Users who have dashboards, alerts, or any monitoring pipelines that consume AI Gateway metrics with the llm_gateway_* prefix.

What Is Changing

All metric names in AI Gateway are being renamed from the llm_gateway_* prefix to ai_gateway_*.

The general rule is a prefix swap: llm_gateway_ → ai_gateway_. Two metrics differ from this rule: llm_gateway_request_total_cost_total → ai_gateway_request_cost_total, and llm_gateway_agent_request_tool_calls_total → ai_gateway_agent_request_tool_calls.

Complete rename map (names as seen in Prometheus scrape):

Core request metrics

Old Name	New Name
llm_gateway_requests_total	ai_gateway_requests_total
llm_gateway_input_tokens_total	ai_gateway_input_tokens_total
llm_gateway_output_tokens_total	ai_gateway_output_tokens_total
llm_gateway_request_total_cost_total	ai_gateway_request_cost_total
llm_gateway_request_model_inference_failure_total	ai_gateway_request_model_inference_failure_total
llm_gateway_config_parsing_failures_total	ai_gateway_config_parsing_failures_total
llm_gateway_request_processing_ms	ai_gateway_request_processing_ms
llm_gateway_first_token_latency_ms	ai_gateway_first_token_latency_ms
llm_gateway_inter_token_latency_ms	ai_gateway_inter_token_latency_ms

Agent metrics

Old Name	New Name
llm_gateway_agent_requests_total	ai_gateway_agent_requests_total
llm_gateway_agent_request_duration_ms	ai_gateway_agent_request_duration_ms
llm_gateway_agent_request_tool_calls_total	ai_gateway_agent_request_tool_calls
llm_gateway_agent_request_iteration_limit_reached_total	ai_gateway_agent_request_iteration_limit_reached_total
llm_gateway_agent_llm_latency_ms	ai_gateway_agent_llm_latency_ms
llm_gateway_agent_tool_calls_total	ai_gateway_agent_tool_calls_total
llm_gateway_agent_tool_latency_ms	ai_gateway_agent_tool_latency_ms
llm_gateway_agent_mcp_connect_latency_ms	ai_gateway_agent_mcp_connect_latency_ms

Rate limit & routing metrics

Old Name	New Name
llm_gateway_load_balanced_requests_total	ai_gateway_load_balanced_requests_total
llm_gateway_fallback_requests_total	ai_gateway_fallback_requests_total
llm_gateway_rate_limit_applied_total	ai_gateway_rate_limit_applied_total
llm_gateway_rate_limit_nominated_total	ai_gateway_rate_limit_nominated_total
llm_gateway_rate_limit_requests_total (deprecated)	ai_gateway_rate_limit_requests_total (deprecated)

Budget metrics

Old Name	New Name
llm_gateway_budget_applied_total	ai_gateway_budget_applied_total
llm_gateway_budget_nominated_total	ai_gateway_budget_nominated_total
llm_gateway_budget_usage	ai_gateway_budget_usage
llm_gateway_budget_requests_total (deprecated)	ai_gateway_budget_requests_total (deprecated)

Guardrail metrics

Old Name	New Name
llm_gateway_guardrails_requests_total	ai_gateway_guardrails_requests_total
llm_gateway_guardrail_requests_total	ai_gateway_guardrail_requests_total
llm_gateway_guardrail_execution_latency_ms	ai_gateway_guardrail_execution_latency_ms

Model health metrics

Old Name	New Name
llm_gateway_model_cooldown_state_total	ai_gateway_model_cooldown_state_total
llm_gateway_model_threshold_latency_exceeded_total	ai_gateway_model_threshold_latency_exceeded_total

Why This Change

The product has been rebranded from LLM Gateway to AI Gateway to reflect the broader set of capabilities it now supports (agents, MCP, guardrails, etc.). Aligning the OTel metric names with the product name makes monitoring consistent with the rest of the platform.

Transition: Dual-Write Mode

To avoid breaking existing dashboards and alerts immediately, a dual-write mode was introduced in v0.136.0. When enabled, the /metrics endpoint emits both the old llm_gateway_* metrics and the new ai_gateway_* metrics in a single scrape response.

Dual-write is controlled by the environment variable:

ENABLE_DOUBLE_WRITE_FOR_METRICS=true   # default: true (since v0.136.0)

During the transition period, both sets of metrics are available simultaneously so you can update your dashboards at your own pace.

The old llm_gateway_* metrics will no longer be published after 30th June 2026. Ensure your dashboards and alerts are migrated to the new ai_gateway_* names before this date.

What You Need to Do

1. Verify dual-write is active

   Confirm that ENABLE_DOUBLE_WRITE_FOR_METRICS is set to true (it is true by default). Scrape the /metrics endpoint and verify you see both llm_gateway_* and ai_gateway_* series.

2. Update dashboards and alerts

   Replace all references to llm_gateway_* OTel metric names with the corresponding ai_gateway_* names in your Grafana dashboards, Prometheus alerting rules, and any other monitoring configuration.

   Use the rename table above as your migration reference. The general pattern is:

   • Prefix: llm_gateway_ → ai_gateway_ (only change visible in the scraped output — counters retain _total as the Prometheus exporter re-adds it)
3. Disable dual-write after migration

   Once all dashboards and alerts have been updated to use the new ai_gateway_* names, set ENABLE_DOUBLE_WRITE_FOR_METRICS=false to stop emitting the legacy metrics and reduce scrape payload size.

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If you have questions or need help with the migration, reach out to [e-mail] — we’re happy to assist.