diff --git a/Sources/Flush.swift b/Sources/Flush.swift
index 510365bf..a11618bb 100644
--- a/Sources/Flush.swift
+++ b/Sources/Flush.swift
@@ -25,16 +25,32 @@ class Flush: AppLifecycle {
     var flushOnBackground = true
     var _flushInterval = 0.0
     var _flushBatchSize = APIConstants.maxBatchSize
-    private let flushIntervalReadWriteLock: DispatchQueue
+    private var _serverURL =  BasePath.DefaultMixpanelAPI
+    private let flushRequestReadWriteLock: DispatchQueue
 
+    
+    var serverURL: String {
+        get {
+            flushRequestReadWriteLock.sync {
+                return _serverURL
+            }
+        }
+        set {
+            flushRequestReadWriteLock.sync(flags: .barrier, execute: {
+                _serverURL = newValue
+                self.flushRequest.serverURL = newValue
+            })
+        }
+    }
+    
     var flushInterval: Double {
         get {
-            flushIntervalReadWriteLock.sync {
+            flushRequestReadWriteLock.sync {
                 return _flushInterval
             }
         }
         set {
-            flushIntervalReadWriteLock.sync(flags: .barrier, execute: {
+            flushRequestReadWriteLock.sync(flags: .barrier, execute: {
                 _flushInterval = newValue
             })
 
@@ -52,9 +68,10 @@ class Flush: AppLifecycle {
         }
     }
 
-    required init(basePathIdentifier: String) {
-        self.flushRequest = FlushRequest(basePathIdentifier: basePathIdentifier)
-        flushIntervalReadWriteLock = DispatchQueue(label: "com.mixpanel.flush_interval.lock", qos: .utility, attributes: .concurrent, autoreleaseFrequency: .workItem)
+    required init(serverURL: String) {
+        self.flushRequest = FlushRequest(serverURL: serverURL)
+        _serverURL = serverURL
+        flushRequestReadWriteLock = DispatchQueue(label: "com.mixpanel.flush_interval.lock", qos: .utility, attributes: .concurrent, autoreleaseFrequency: .workItem)
     }
 
     func flushQueue(_ queue: Queue, type: FlushType, headers: [String: String], queryItems: [URLQueryItem]) {
diff --git a/Sources/FlushRequest.swift b/Sources/FlushRequest.swift
index f14485cc..bf260364 100644
--- a/Sources/FlushRequest.swift
+++ b/Sources/FlushRequest.swift
@@ -46,7 +46,7 @@ class FlushRequest: Network {
                                              parse: responseParser)
         var result = false
         let semaphore = DispatchSemaphore(value: 0)
-        flushRequestHandler(BasePath.getServerURL(identifier: basePathIdentifier),
+        flushRequestHandler(serverURL,
                             resource: resource,
                             completion: { success in
                                 result = success
diff --git a/Sources/MixpanelInstance.swift b/Sources/MixpanelInstance.swift
index 11145234..d01ad7b5 100644
--- a/Sources/MixpanelInstance.swift
+++ b/Sources/MixpanelInstance.swift
@@ -167,7 +167,7 @@ open class MixpanelInstance: CustomDebugStringConvertible, FlushDelegate, AEDele
     /// https://api.mixpanel.com.
     open var serverURL = BasePath.DefaultMixpanelAPI {
         didSet {
-            BasePath.namedBasePaths[name] = serverURL
+            flushInstance.serverURL = serverURL
         }
     }
     
@@ -323,7 +323,6 @@ open class MixpanelInstance: CustomDebugStringConvertible, FlushDelegate, AEDele
         trackAutomaticEventsEnabled = trackAutomaticEvents
         if let serverURL = serverURL {
             self.serverURL = serverURL
-            BasePath.namedBasePaths[name] = serverURL
         }
         self.proxyServerDelegate = proxyServerDelegate
 #if DEBUG
@@ -347,7 +346,7 @@ open class MixpanelInstance: CustomDebugStringConvertible, FlushDelegate, AEDele
         self.useUniqueDistinctId = useUniqueDistinctId
         
         readWriteLock = ReadWriteLock(label: "com.mixpanel.globallock")
-        flushInstance = Flush(basePathIdentifier: name)
+        flushInstance = Flush(serverURL: self.serverURL)
         sessionMetadata = SessionMetadata(trackingQueue: trackingQueue)
         trackInstance = Track(apiToken: self.apiToken,
                               instanceName: self.name,
diff --git a/Sources/Network.swift b/Sources/Network.swift
index 7e7774ea..5d78d438 100644
--- a/Sources/Network.swift
+++ b/Sources/Network.swift
@@ -10,7 +10,6 @@ import Foundation
 
 struct BasePath {
     static let DefaultMixpanelAPI = "https://api.mixpanel.com"
-    static var namedBasePaths = [String: String]()
     
     static func buildURL(base: String, path: String, queryItems: [URLQueryItem]?) -> URL? {
         guard let url = URL(string: base) else {
@@ -25,10 +24,6 @@ struct BasePath {
         components.percentEncodedQuery = components.percentEncodedQuery?.replacingOccurrences(of: "+", with: "%2B")
         return components.url
     }
-    
-    static func getServerURL(identifier: String) -> String {
-        return namedBasePaths[identifier] ?? DefaultMixpanelAPI
-    }
 }
 
 enum RequestMethod: String {
@@ -64,10 +59,10 @@ public struct ServerProxyResource {
 
 class Network {
     
-    let basePathIdentifier: String
+    var serverURL: String
     
-    required init(basePathIdentifier: String) {
-        self.basePathIdentifier = basePathIdentifier
+    required init(serverURL: String) {
+        self.serverURL = serverURL
     }
     
     class func apiRequest<A>(base: String,