metadata

const (
	// SubsetFilterNamespace is the key for the outer namespace struct in the metadata field of the extproc request that is used to wrap the subset filter.
	SubsetFilterNamespace = "envoy.lb.subset_hint"
	// SubsetFilterKey is the metadata key used by Envoy to specify an array candidate pods for serving the request.
	// If not specified, all the pods that are associated with the pool are candidates.
	SubsetFilterKey = "x-gateway-destination-endpoint-subset"
	// DestinationEndpointNamespace is the key for the outer namespace struct in the metadata field of the extproc response that is used to wrap the target endpoint.
	DestinationEndpointNamespace = "envoy.lb"
	// DestinationEndpointKey is the header and response metadata key used by Envoy to route to the appropriate pod.
	DestinationEndpointKey = "x-gateway-destination-endpoint"
	// DestinationEndpointServedKey is the metadata key used by Envoy to specify the endpoint that served the request.
	DestinationEndpointServedKey = "x-gateway-destination-endpoint-served"
	// FlowFairnessIDKey is the header key used to pass the fairness ID to be used in Flow Control.
	FlowFairnessIDKey = "x-llm-d-inference-fairness-id"
	// OldFlowFairnessIDKey is the deprecated alias for FlowFairnessIDKey.
	OldFlowFairnessIDKey = "x-gateway-inference-fairness-id"
	// ObjectiveKey is the header key used to specify the objective of an incoming request.
	ObjectiveKey = "x-llm-d-inference-objective"
	// OldObjectiveKey is the deprecated alias for ObjectiveKey.
	OldObjectiveKey = "x-gateway-inference-objective"
	// ModelNameRewriteKey is the header key used to specify the model name to be used when the request is forwarded to the model server.
	ModelNameRewriteKey = "x-llm-d-model-name-rewrite"
	// OldModelNameRewriteKey is the deprecated alias for ModelNameRewriteKey.
	OldModelNameRewriteKey = "x-gateway-model-name-rewrite"
	// TTFTSLOHeaderKey is the header key used to specify the time-to-first-token SLO in milliseconds.
	TTFTSLOHeaderKey = "x-llm-d-slo-ttft-ms"
	// OldTTFTSLOHeaderKey is the deprecated alias for TTFTSLOHeaderKey.
	OldTTFTSLOHeaderKey = "x-slo-ttft-ms"
	// TPOTSLOHeaderKey is the header key used to specify the time-per-output-token SLO in milliseconds.
	TPOTSLOHeaderKey = "x-llm-d-slo-tpot-ms"
	// OldTPOTSLOHeaderKey is the deprecated alias for TPOTSLOHeaderKey.
	OldTPOTSLOHeaderKey = "x-slo-tpot-ms"

	// DefaultFairnessID is the default fairness ID used when no ID is provided in the request.
	// This ensures that requests without explicit fairness identifiers are still grouped and managed by the Flow Control
	// system.
	DefaultFairnessID = "default-flow"
)