diff --git a/lib/modules/auth/PhoneAuthListener.js b/lib/modules/auth/PhoneAuthListener.js
new file mode 100644
index 00000000..04d731bd
--- /dev/null
+++ b/lib/modules/auth/PhoneAuthListener.js
@@ -0,0 +1,301 @@
+// @flow
+import INTERNALS from './../../internals';
+import { generatePushID, isFunction, isAndroid, isIOS, isString } from './../../utils';
+
+type PhoneAuthSnapshot = {
+  state: 'sent' | 'timeout' | 'verified' | 'error',
+  verificationId: string,
+  code: string | null,
+  error: Error | null,
+};
+
+type PhoneAuthError = {
+  code: string | null,
+  verificationId: string,
+  message: string | null,
+  stack: string | null,
+};
+
+export default class PhoneAuthListener {
+  _auth: Object;
+  _reject: Function | null;
+  _resolve: Function | null;
+  _promise: Promise | null;
+  _credential: Object | null;
+  _timeout: number;
+  _phoneAuthRequestKey: string;
+  _publicEvents: Object;
+  _internalEvents: Object;
+
+  /**
+   *
+   * @param auth
+   * @param phoneNumber
+   * @param timeout
+   */
+  constructor(auth: Object, phoneNumber: string, timeout): PhoneAuthListener {
+    this._auth = auth;
+    this._reject = null;
+    this._resolve = null;
+    this._promise = null;
+    this._credential = null;
+
+    this._timeout = timeout || 20000; // 20 secs
+    this._phoneAuthRequestKey = generatePushID();
+
+    // internal events
+    this._internalEvents = {
+      codeSent: `phone:auth:${this._phoneAuthRequestKey}:onCodeSent`,
+      verificationFailed: `phone:auth:${this._phoneAuthRequestKey}:onVerificationFailed`,
+      verificationComplete: `phone:auth:${this._phoneAuthRequestKey}:onVerificationComplete`,
+      codeAutoRetrievalTimeout: `phone:auth:${this._phoneAuthRequestKey}:onCodeAutoRetrievalTimeout`,
+    };
+
+    // user observer events
+    this._publicEvents = {
+      // error cb
+      error: `phone:auth:${this._phoneAuthRequestKey}:error`,
+      // observer
+      event: `phone:auth:${this._phoneAuthRequestKey}:event`,
+      // success cb
+      success: `phone:auth:${this._phoneAuthRequestKey}:success`,
+    };
+
+    // setup internal event listeners
+    this._subscribeToEvents();
+
+    // start verification flow natively
+    this._auth._native.verifyPhoneNumber(
+      phoneNumber,
+      this._phoneAuthRequestKey,
+    );
+  }
+
+  /**
+   * Subscribes to all EE events on this._internalEvents
+   * @private
+   */
+  _subscribeToEvents() {
+    const events = Object.keys(this._internalEvents);
+
+    for (let i = 0, len = events.length; i < len; i++) {
+      const type = events[i];
+      this._auth.once(this._internalEvents[type], this[`_${type}Handler`].bind(this));
+    }
+  }
+
+  /**
+   * Subscribe a users listener cb to the snapshot events.
+   * @param observer
+   * @private
+   */
+  _addUserObserver(observer) {
+    this._auth.on(this._publicEvents.event, observer);
+  }
+
+  /**
+   * Send a snapshot event to users event observer.
+   * @param snapshot PhoneAuthSnapshot
+   * @private
+   */
+  _emitToObservers(snapshot: PhoneAuthSnapshot) {
+    this._auth.emit(this._publicEvents.event, snapshot);
+  }
+
+  /**
+   * Send a error snapshot event to any subscribed errorCb's
+   * @param snapshot
+   * @private
+   */
+  _emitToErrorCb(snapshot) {
+    const error = snapshot.error;
+    error.verificationId = snapshot.verificationId;
+
+    if (this._reject) this._reject(error);
+    this._auth.emit(this._publicEvents.error, error);
+  }
+
+  /**
+   * Send a success snapshot event to any subscribed completeCb's
+   * @param snapshot
+   * @private
+   */
+  _emitToSuccessCb(snapshot) {
+    if (this._resolve) this._resolve(snapshot);
+    this._auth.emit(this._publicEvents.success, snapshot);
+  }
+
+  /**
+   * Removes all listeners for this phone auth instance
+   * @private
+   */
+  _removeAllListeners() {
+    setTimeout(() => { // move to next event loop - not sure if needed
+      // internal listeners
+      const events = Object.values(this._internalEvents);
+
+      for (let i = 0, len = events.length; i < len; i++) {
+        this._auth.removeAllListeners(events[i]);
+      }
+
+      // user observer listeners
+      const publicEvents = Object.values(this._publicEvents);
+
+      for (let i = 0, len = events.length; i < len; i++) {
+        this._auth.removeAllListeners(publicEvents[i]);
+      }
+    }, 0);
+  }
+
+  /**
+   * Create a new internal deferred promise, if not already created
+   * @private
+   */
+  _promiseDeferred() {
+    if (!this._promise) {
+      this._promise = new Promise((resolve, reject) => {
+        this._resolve = (result) => {
+          this._resolve = null;
+          return resolve(result);
+        };
+
+        this._reject = (possibleError) => {
+          this._reject = null;
+          return reject(possibleError);
+        };
+      });
+    }
+  }
+
+  /* --------------------------
+   --- INTERNAL EVENT HANDLERS
+   ---------------------------- */
+
+  /**
+   * Internal code sent event handler
+   * @param verificationId
+   * @private
+   */
+  _codeSentHandler(verificationId) {
+    const snapshot: PhoneAuthSnapshot = {
+      verificationId,
+      code: null,
+      error: null,
+      state: 'sent',
+    };
+
+    this._emitToObservers(snapshot);
+
+    if (isIOS) {
+      this._emitToSuccessCb(snapshot);
+    }
+
+    if (isAndroid) {
+      // android can auto retrieve so we don't emit to successCb immediately,
+      // if auto retrieve times out then that will emit to successCb
+    }
+  }
+
+  /**
+   * Internal code auto retrieve timeout event handler
+   * @param verificationId
+   * @private
+   */
+  _codeAutoRetrievalTimeoutHandler(verificationId) {
+    const snapshot: PhoneAuthSnapshot = {
+      verificationId,
+      code: null,
+      error: null,
+      state: 'timeout',
+    };
+
+    this._emitToObservers(snapshot);
+    this._emitToSuccessCb(snapshot);
+  }
+
+  /**
+   * Internal verification complete event handler
+   * @param credential
+   * @private
+   */
+  _verificationCompleteHandler(credential) {
+    const snapshot: PhoneAuthSnapshot = {
+      verificationId: credential.verificationId,
+      code: credential.code || null,
+      error: null,
+      state: 'verified',
+    };
+
+    this._emitToObservers(snapshot);
+    this._emitToSuccessCb(snapshot);
+    this._removeAllListeners();
+  }
+
+  /**
+   * Internal verification failed event handler
+   * @param errObject
+   * @private
+   */
+  _verificationFailedHandler(errObject) {
+    const snapshot: PhoneAuthSnapshot = {
+      verificationId: errObject.verificationId,
+      code: null,
+      error: null,
+      state: 'error',
+    };
+
+
+    this._emitToObservers(snapshot);
+    this._emitToErrorCb(snapshot);
+    this._removeAllListeners();
+  }
+
+
+  /* -------------
+   -- PUBLIC API
+   --------------*/
+
+  on(event: string, observer: () => PhoneAuthSnapshot, errorCb?: () => PhoneAuthError, successCb?: () => PhoneAuthSnapshot) {
+    if (!isString(event)) {
+      throw new Error(INTERNALS.STRINGS.ERROR_MISSING_ARG_NAMED('event', 'string', 'on'));
+    }
+
+    if (event !== 'state_changed') {
+      throw new Error(INTERNALS.STRINGS.ERROR_ARG_INVALID_VALUE('event', 'state_changed', event));
+    }
+
+    if (!isFunction(observer)) {
+      throw new Error(INTERNALS.STRINGS.ERROR_MISSING_ARG_NAMED('observer', 'function', 'on'));
+    }
+
+    this._addUserObserver(observer);
+
+    if (isFunction(errorCb)) {
+      this._auth.once(this._publicEvents.error, errorCb);
+    }
+
+    if (isFunction(successCb)) {
+      this._auth.once(this._publicEvents.success, successCb);
+    }
+
+    return this;
+  }
+
+  /**
+   * Promise .then proxy
+   * @param fn
+   */
+  then(fn) {
+    this._promiseDeferred();
+    return this._promise.then.bind(this._promise)(fn);
+  }
+
+  /**
+   * Promise .catch proxy
+   * @param fn
+   */
+  catch(fn) {
+    this._promiseDeferred();
+    return this._promise.catch.bind(this._promise)(fn);
+  }
+}