diff --git a/src/config.js b/src/config.js
index 096f432..1dd8173 100644
--- a/src/config.js
+++ b/src/config.js
@@ -14,6 +14,7 @@ export default class RTConfig {
     this.debugMode = false
     this.connectQuery = {}
     this.socketConfigTransform = null
+    this.hostResolver = null
 
     this.socketConfig = null
 
@@ -25,6 +26,12 @@ export default class RTConfig {
       return
     }
 
+    if (!isUndefined(config.hostResolver)) {
+      if (isFunction(config.hostResolver)) {
+        this.hostResolver = config.hostResolver
+      }
+    }
+
     if (!isUndefined(config.appId)) {
       if (!isString(config.appId)) {
         throw new Error('"appId" must be String.')
@@ -79,18 +86,33 @@ export default class RTConfig {
     return this.connectQuery
   }
 
-  async prepare() {
-    if (!isString(this.lookupPath)) {
-      throw new Error('lookupPath must be String')
+  getSocketConfig() {
+    return this.socketConfig
+  }
+
+  async getHost() {
+    let host
+
+    if (this.hostResolver) {
+      host = await this.hostResolver()
+    } else {
+      host = await Request.get(this.lookupPath).set(this.lookupHeaders)
     }
 
-    const host = await Request.get(this.lookupPath).set(this.lookupHeaders)
+    return host
+  }
+
+  async prepare() {
+    const query = this.getConnectQuery()
+    const host = await this.getHost()
+
+    if (!host) {
+      throw new Error('Host is not defined')
+    }
 
     const url = this.appId ? `${ host }/${ this.appId }` : host
     const path = this.appId ? `/${ this.appId }` : undefined
 
-    const query = this.getConnectQuery()
-
     this.socketConfig = {
       host,
       url,
@@ -104,16 +126,8 @@ export default class RTConfig {
     }
 
     if (this.socketConfigTransform) {
-      const socketConfig = await this.socketConfigTransform(this.socketConfig)
-
-      if (socketConfig) {
-        this.socketConfig = socketConfig
-      }
+      this.socketConfig = await this.socketConfigTransform(this.socketConfig) || this.socketConfig
     }
   }
-
-  getSocketConfig() {
-    return this.socketConfig
-  }
 }