request

var (
	// InputControlHeaders are sent by the Gateway/User to control EPP behavior.
	// We must extract these, then strip them so they don't leak to the backend.
	InputControlHeaders = lowerHeaderNames(
		metadata.FlowFairnessIDKey,
		metadata.ObjectiveKey,
		metadata.ModelNameRewriteKey,
		metadata.SubsetFilterKey,
		metadata.TTFTSLOHeaderKey,
		metadata.TPOTSLOHeaderKey,
	)

	// OutputInjectionHeaders are headers EPP injects for the backend.
	// If the user sends these, they must be stripped to prevent ambiguity.
	OutputInjectionHeaders = addLowerHeaders(
		lowerHeaderNames(
			metadata.DestinationEndpointKey,
			metadata.DestinationEndpointServedKey,
		),
		errcommon.RequestDroppedReasonHeaderKey,
	)

	// ProtocolHeaders are managed by the proxy layer (Envoy/EPP).
	ProtocolHeaders = sets.New("content-length")
)