chore(deps): Bump lodash from 4.17.21 to 4.17.23

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.21 to 4.17.23.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](https://github.com/lodash/lodash/compare/4.17.21...4.17.23)

---
updated-dependencies:
- dependency-name: lodash
  dependency-version: 4.17.23
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

.all-contributorsrc

@@ -11,6 +11,13 @@
       "avatar_url": "https://avatars.githubusercontent.com/u/227265405?v=4",
       "profile": "https://github.com/jagmandan",
       "contributions": ["code"]
+    },
+    {
+      "login": "remiolivier",
+      "name": "remiolivier",
+      "avatar_url": "https://avatars.githubusercontent.com/u/1379047?v=4",
+      "profile": "https://github.com/remiolivier",
+      "contributions": ["code"]
     }
   ],
   "contributorsPerLine": 7,

.github/dependabot.yml

@@ -8,7 +8,7 @@ updates:
   - package-ecosystem: 'npm' # See documentation for possible values
     directory: '/' # Location of package manifests
     schedule:
-      interval: 'daily'
+      interval: 'weekly'
     labels:
       - 'dependencies'
     commit-message:

README.md

@@ -2,7 +2,7 @@
 
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
 
-[![All Contributors](https://img.shields.io/badge/all_contributors-1-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-2-orange.svg?style=flat-square)](#contributors-)
 
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
@@ -247,6 +247,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
   <tbody>
     <tr>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/jagmandan"><img src="https://avatars.githubusercontent.com/u/227265405?v=4?s=100" width="100px;" alt="jagmandan"/><br /><sub><b>jagmandan</b></sub></a><br /><a href="https://github.com/bourquep/mysa-js-sdk/commits?author=jagmandan" title="Code">💻</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/remiolivier"><img src="https://avatars.githubusercontent.com/u/1379047?v=4?s=100" width="100px;" alt="remiolivier"/><br /><sub><b>remiolivier</b></sub></a><br /><a href="https://github.com/bourquep/mysa-js-sdk/commits?author=remiolivier" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>

eslint.config.js

@@ -16,7 +16,8 @@ export default [
     rules: {
       'jsdoc/tag-lines': 'off',
       'jsdoc/check-tag-names': 'off',
-      'jsdoc/valid-types': 'off'
+      'jsdoc/valid-types': 'off',
+      'jsdoc/require-throws-type': 'off'
     }
   },
   { plugins: { tsdoc }, rules: { 'tsdoc/syntax': 'warn' } }

example/main.ts

@@ -65,9 +65,10 @@ async function main() {
     client.emitter.on('statusChanged', (status) => {
       try {
         const device = devices.DevicesObj[status.deviceId];
-        const watts = status.current !== undefined ? status.current * device.Voltage : undefined;
+        const watts =
+          status.current !== undefined && device.Voltage !== undefined ? status.current * device.Voltage : undefined;
         rootLogger.info(
-          `'${device.Name}' status changed: ${status.temperature}°C, ${status.humidity}%, ${watts ?? 'na'}W`
+          `[${status.deviceId}] '${device.Name ?? 'Unknown'}' status changed: ${status.temperature}°C, ${status.humidity}%, ${watts ?? 'na'}W`
         );
       } catch (error) {
         rootLogger.error(error, `Error processing status update for device '${status.deviceId}'`);
@@ -77,7 +78,9 @@ async function main() {
     client.emitter.on('setPointChanged', (change) => {
       try {
         const device = devices.DevicesObj[change.deviceId];
-        rootLogger.info(`'${device.Name}' setpoint changed from ${change.previousSetPoint} to ${change.newSetPoint}`);
+        rootLogger.info(
+          `'${device.Name ?? 'Unknown'}' setpoint changed from ${change.previousSetPoint} to ${change.newSetPoint}`
+        );
       } catch (error) {
         rootLogger.error(error, `Error processing setpoint update for device '${change.deviceId}'`);
       }
@@ -86,7 +89,7 @@ async function main() {
     client.emitter.on('stateChanged', (change) => {
       try {
         const device = devices.DevicesObj[change.deviceId];
-        rootLogger.info(change, `'${device.Name}' state changed.`);
+        rootLogger.info(change, `'${device.Name ?? 'Unknown'}' state changed.`);
       } catch (error) {
         rootLogger.error(error, `Error processing state update for device '${change.deviceId}'`);
       }
@@ -96,7 +99,7 @@ async function main() {
   await Promise.all(
     Object.entries(devices.DevicesObj).map(async ([deviceId, device]) => {
       const serial = await client.getDeviceSerialNumber(deviceId);
-      rootLogger.info(`Serial number for device '${deviceId}' (${device.Name}): ${serial}`);
+      rootLogger.info(`Serial number for device '${deviceId}' (${device.Name ?? 'Unknown'}): ${serial}`);
 
       await client.startRealtimeUpdates(deviceId);
     })

package.json

@@ -50,34 +50,35 @@
     "brace-expansion": "^2.0.2"
   },
   "dependencies": {
-    "@aws-sdk/client-iot": "3.901.0",
-    "@aws-sdk/credential-providers": "3.901.0",
-    "amazon-cognito-identity-js": "6.3.15",
-    "aws-iot-device-sdk-v2": "1.22.0",
-    "dayjs": "1.11.13",
-    "lodash": "4.17.21"
+    "@aws-sdk/client-iot": "3.936.0",
+    "@aws-sdk/credential-providers": "3.940.0",
+    "amazon-cognito-identity-js": "6.3.16",
+    "aws-iot-device-sdk-v2": "1.23.1",
+    "dayjs": "1.11.19",
+    "lodash": "4.17.23",
+    "nanoid": "5.1.6"
   },
   "devDependencies": {
-    "@eslint/js": "9.34.0",
-    "@semantic-release/npm": "12.0.2",
-    "@types/lodash": "4.17.20",
-    "@types/node": "24.3.0",
+    "@eslint/js": "9.39.1",
+    "@semantic-release/npm": "13.1.2",
+    "@types/lodash": "4.17.21",
+    "@types/node": "24.10.1",
     "conventional-changelog-conventionalcommits": "9.1.0",
-    "dotenv": "17.2.1",
-    "eslint": "9.34.0",
-    "eslint-plugin-jsdoc": "54.1.1",
-    "eslint-plugin-tsdoc": "0.4.0",
-    "pino": "9.13.0",
-    "pino-pretty": "13.0.0",
+    "dotenv": "17.2.3",
+    "eslint": "9.39.1",
+    "eslint-plugin-jsdoc": "61.4.1",
+    "eslint-plugin-tsdoc": "0.5.0",
+    "pino": "10.1.0",
+    "pino-pretty": "13.1.2",
     "prettier": "3.6.2",
-    "prettier-plugin-jsdoc": "1.3.3",
-    "prettier-plugin-organize-imports": "4.2.0",
-    "semantic-release": "24.2.7",
+    "prettier-plugin-jsdoc": "1.5.0",
+    "prettier-plugin-organize-imports": "4.3.0",
+    "semantic-release": "25.0.2",
     "tsup": "8.5.0",
-    "tsx": "4.20.3",
-    "typedoc": "0.28.13",
-    "typedoc-material-theme": "1.4.0",
-    "typescript": "5.9.2",
-    "typescript-eslint": "8.41.0"
+    "tsx": "4.20.6",
+    "typedoc": "0.28.14",
+    "typedoc-material-theme": "1.4.1",
+    "typescript": "5.9.3",
+    "typescript-eslint": "8.46.2"
   }
 }

src/api/Errors.ts

@@ -32,3 +32,22 @@ export class MysaApiError extends Error {
     this.statusText = apiResponse.statusText;
   }
 }
+
+/** Error thrown when an MQTT publish ultimately fails after retry attempts. */
+export class MqttPublishError extends Error {
+  /**
+   * Creates a new MqttPublishError instance.
+   *
+   * @param message - A human-readable description of the publish failure.
+   * @param attempts - The number of attempts that were made before giving up.
+   * @param original - The original error object thrown by the underlying MQTT library (optional).
+   */
+  constructor(
+    message: string,
+    public attempts: number,
+    public original?: unknown
+  ) {
+    super(message);
+    this.name = 'MqttPublishError';
+  }
+}

src/api/MysaApiClient.ts

@@ -19,16 +19,28 @@ import {
   CognitoUserSession
 } from 'amazon-cognito-identity-js';
 import { iot, mqtt } from 'aws-iot-device-sdk-v2';
-import dayjs from 'dayjs';
+import { hash } from 'crypto';
+import dayjs, { Dayjs } from 'dayjs';
 import duration from 'dayjs/plugin/duration.js';
-import { MysaApiError, UnauthenticatedError } from './Errors';
+import { customAlphabet } from 'nanoid';
+import { MqttPublishError, MysaApiError, UnauthenticatedError } from './Errors';
 import { Logger, VoidLogger } from './Logger';
 import { MysaApiClientEventTypes } from './MysaApiClientEventTypes';
 import { MysaApiClientOptions } from './MysaApiClientOptions';
-import { MysaDeviceMode } from './MysaDeviceMode';
+import { MysaDeviceMode, MysaFanSpeedMode } from './MysaDeviceMode';
 
 dayjs.extend(duration);
 
+const getRandomClientId = customAlphabet('1234567890abcdefghijklmnopqrstuvwxyz', 8);
+
+/** Options for MQTT publish operations. */
+export interface MqttPublishOptions {
+  /** Maximum number of publish attempts before failing (default: 5). */
+  maxAttempts?: number;
+  /** Base delay in milliseconds used for exponential backoff calculation (default: 500). */
+  baseDelayMs?: number;
+}
+
 const AwsRegion = 'us-east-1';
 const CognitoUserPoolId = 'us-east-1_GUFWfhI7g';
 const CognitoClientId = '19efs8tgqe942atbqmot5m36t3';
@@ -78,6 +90,18 @@ export class MysaApiClient {
   /** A promise that resolves to the MQTT connection used for real-time updates. */
   private _mqttConnectionPromise?: Promise<mqtt.MqttClientConnection>;
 
+  /** Stable per-process MQTT client id (prevents collisions between multiple processes). */
+  private _mqttClientId?: string;
+
+  /** Expiration time of the credentials currently in use by the MQTT client. */
+  private _mqttCredentialsExpiration?: Dayjs;
+
+  /** Interrupt timestamps for storm / collision detection. */
+  private _mqttInterrupts: number[] = [];
+
+  /** Whether a forced MQTT reset is currently in progress (guards against re-entrancy). */
+  private _mqttResetInProgress = false;
+
   /** The device IDs that are currently being updated in real-time, mapped to their respective timeouts. */
   private _realtimeDeviceIds: Map<string, NodeJS.Timeout> = new Map();
 
@@ -165,6 +189,9 @@ export class MysaApiClient {
   async login(emailAddress: string, password: string): Promise<void> {
     this._cognitoUser = undefined;
     this._cognitoUserSession = undefined;
+    this._mqttClientId = undefined;
+    this._mqttInterrupts = [];
+
     this.emitter.emit('sessionChanged', this.session);
 
     return new Promise((resolve, reject) => {
@@ -210,7 +237,7 @@ export class MysaApiClient {
   async getDevices(): Promise<Devices> {
     this._logger.debug(`Fetching devices...`);
 
-    const session = await this.getFreshSession();
+    const session = await this._getFreshSession();
 
     const response = await this._fetcher(`${MysaApiBaseUrl}/devices`, {
       headers: {
@@ -249,7 +276,7 @@ export class MysaApiClient {
   async getDeviceSerialNumber(deviceId: string): Promise<string | undefined> {
     this._logger.debug(`Fetching serial number for device ${deviceId}...`);
 
-    const session = await this.getFreshSession();
+    const session = await this._getFreshSession();
 
     // Get AWS credentials for IoT client
     const credentialsProvider = fromCognitoIdentityPool({
@@ -292,7 +319,7 @@ export class MysaApiClient {
   async getDeviceFirmwares(): Promise<Firmwares> {
     this._logger.debug(`Fetching device firmwares...`);
 
-    const session = await this.getFreshSession();
+    const session = await this._getFreshSession();
 
     const response = await this._fetcher(`${MysaApiBaseUrl}/devices/firmware`, {
       headers: {
@@ -317,7 +344,7 @@ export class MysaApiClient {
   async getDeviceStates(): Promise<DeviceStates> {
     this._logger.debug(`Fetching device states...`);
 
-    const session = await this.getFreshSession();
+    const session = await this._getFreshSession();
 
     const response = await this._fetcher(`${MysaApiBaseUrl}/devices/state`, {
       headers: {
@@ -349,15 +376,20 @@ export class MysaApiClient {
    *
    * // Set temperature and mode
    * await client.setDeviceState('device123', 20, 'heat');
+   *
+   * // Set fan speed
+   * await client.setDeviceState('device123', undefined, undefined, 'auto');
    * ```
    *
    * @param deviceId - The ID of the device to control.
    * @param setPoint - The target temperature set point (optional).
-   * @param mode - The operating mode to set ('off', 'heat', or undefined to leave unchanged).
+   * @param mode - The operating mode to set (one of MysaDeviceMode values, or undefined to leave unchanged).
+   * @param fanSpeed - The fan speed mode to set ('low', 'medium', 'high', 'max', 'auto', or undefined to leave
+   *   unchanged).
    * @throws {@link UnauthenticatedError} When the user is not authenticated.
    * @throws {@link Error} When MQTT connection or command sending fails.
    */
-  async setDeviceState(deviceId: string, setPoint?: number, mode?: MysaDeviceMode) {
+  async setDeviceState(deviceId: string, setPoint?: number, mode?: MysaDeviceMode, fanSpeed?: MysaFanSpeedMode) {
     this._logger.debug(`Setting device state for '${deviceId}'`);
 
     if (!this._cachedDevices) {
@@ -367,18 +399,21 @@ export class MysaApiClient {
     const device = this._cachedDevices.DevicesObj[deviceId];
 
     this._logger.debug(`Initializing MQTT connection...`);
-    const mqttConnection = await this.getMqttConnection();
+    const mqttConnection = await this._getMqttConnection();
 
     const now = dayjs();
 
     this._logger.debug(`Sending request to set device state for '${deviceId}'...`);
+    const modeMap = { off: 1, auto: 2, heat: 3, cool: 4, fan_only: 5, dry: 6 };
+    const fanSpeedMap = { auto: 1, low: 3, medium: 5, high: 7, max: 8 };
+
     const payload = serializeMqttPayload<ChangeDeviceState>({
       msg: InMessageType.CHANGE_DEVICE_STATE,
       id: now.valueOf(),
       time: now.unix(),
       ver: '1.0',
       src: {
-        ref: this.session!.username,
+        ref: this.session?.username ?? '',
         type: 100
       },
       dest: {
@@ -390,22 +425,31 @@ export class MysaApiClient {
         ver: 1,
         type: device.Model.startsWith('BB-V1')
           ? 1
-          : device.Model.startsWith('BB-V2')
-            ? device.Model.endsWith('-L')
-              ? 5
-              : 4
-            : 0,
+          : device.Model.startsWith('AC-V1')
+            ? 2
+            : device.Model.startsWith('BB-V2')
+              ? device.Model.endsWith('-L')
+                ? 5
+                : 4
+              : 0,
         cmd: [
           {
             tm: -1,
             sp: setPoint,
-            md: mode === 'off' ? 1 : mode === 'heat' ? 3 : undefined
+            md: mode ? modeMap[mode] : undefined,
+            fn: fanSpeed ? fanSpeedMap[fanSpeed] : undefined
           }
         ]
       }
     });
 
-    await mqttConnection.publish(`/v1/dev/${deviceId}/in`, payload, mqtt.QoS.AtLeastOnce);
+    try {
+      await this._publishWithRetry(mqttConnection, `/v1/dev/${deviceId}/in`, payload, mqtt.QoS.AtLeastOnce);
+      this._logger.debug(`Device state publish succeeded for '${deviceId}'`);
+    } catch (error) {
+      this._logger.error(`Failed to set device state for '${deviceId}'`, error);
+      throw error;
+    }
   }
 
   /**
@@ -438,11 +482,11 @@ export class MysaApiClient {
     }
 
     this._logger.debug(`Initializing MQTT connection...`);
-    const mqttConnection = await this.getMqttConnection();
+    const mqttConnection = await this._getMqttConnection();
 
     this._logger.debug(`Subscribing to MQTT topic '/v1/dev/${deviceId}/out'...`);
     await mqttConnection.subscribe(`/v1/dev/${deviceId}/out`, mqtt.QoS.AtLeastOnce, (_, payload) => {
-      this.processMqttMessage(payload);
+      this._processMqttMessage(payload);
     });
 
     this._logger.debug(`Sending request to start publishing device status for '${deviceId}'...`);
@@ -452,17 +496,19 @@ export class MysaApiClient {
       Timestamp: dayjs().unix(),
       Timeout: RealtimeKeepAliveInterval.asSeconds()
     });
-    await mqttConnection.publish(`/v1/dev/${deviceId}/in`, payload, mqtt.QoS.AtLeastOnce);
+    await this._publishWithRetry(mqttConnection, `/v1/dev/${deviceId}/in`, payload, mqtt.QoS.AtLeastOnce);
 
     const timer = setInterval(async () => {
       this._logger.debug(`Sending request to keep-alive publishing device status for '${deviceId}'...`);
+
+      const connection = await this._getMqttConnection();
       const payload = serializeMqttPayload<StartPublishingDeviceStatus>({
         Device: deviceId,
         MsgType: InMessageType.START_PUBLISHING_DEVICE_STATUS,
         Timestamp: dayjs().unix(),
         Timeout: RealtimeKeepAliveInterval.asSeconds()
       });
-      await mqttConnection.publish(`/v1/dev/${deviceId}/in`, payload, mqtt.QoS.AtLeastOnce);
+      await this._publishWithRetry(connection, `/v1/dev/${deviceId}/in`, payload, mqtt.QoS.AtLeastOnce);
     }, RealtimeKeepAliveInterval.subtract(10, 'seconds').asMilliseconds());
 
     this._realtimeDeviceIds.set(deviceId, timer);
@@ -487,7 +533,7 @@ export class MysaApiClient {
     }
 
     this._logger.debug(`Initializing MQTT connection...`);
-    const mqttConnection = await this.getMqttConnection();
+    const mqttConnection = await this._getMqttConnection();
 
     this._logger.debug(`Unsubscribing to MQTT topic '/v1/dev/${deviceId}/out'...`);
     await mqttConnection.unsubscribe(`/v1/dev/${deviceId}/out`);
@@ -505,7 +551,7 @@ export class MysaApiClient {
    * @returns A promise that resolves to a valid CognitoUserSession.
    * @throws {@link UnauthenticatedError} When no session exists or refresh fails.
    */
-  private async getFreshSession(): Promise<CognitoUserSession> {
+  private async _getFreshSession(): Promise<CognitoUserSession> {
     if (!this._cognitoUser || !this._cognitoUserSession) {
       throw new UnauthenticatedError('An attempt was made to access a resource without a valid session.');
     }
@@ -543,9 +589,9 @@ export class MysaApiClient {
    * @returns A promise that resolves to an active MQTT connection.
    * @throws {@link Error} When connection establishment fails.
    */
-  private getMqttConnection(): Promise<mqtt.MqttClientConnection> {
+  private _getMqttConnection(): Promise<mqtt.MqttClientConnection> {
     if (!this._mqttConnectionPromise) {
-      this._mqttConnectionPromise = this.createMqttConnection().catch((err) => {
+      this._mqttConnectionPromise = this._createMqttConnection().catch((err) => {
         this._mqttConnectionPromise = undefined;
         throw err;
       });
@@ -554,14 +600,109 @@ export class MysaApiClient {
     return this._mqttConnectionPromise;
   }
 
+  /**
+   * Determines whether an MQTT-related error is considered transient and worth retrying.
+   *
+   * Transient errors include timeouts, cancelled operations due to clean sessions, temporary connectivity loss, and
+   * other recoverable network issues. Fatal errors (auth, permission, configuration) should not be retried at this
+   * layer.
+   *
+   * @param err - The error object thrown by the underlying MQTT operation.
+   * @returns True if the error appears transient and a retry should be attempted; false otherwise.
+   */
+  private _isTransientMqttError(err: unknown): boolean {
+    if (!err || typeof err !== 'object') {
+      return false;
+    }
+
+    const anyErr = err as { error_code?: unknown; error_name?: unknown; error?: unknown; message?: unknown };
+    const code = anyErr.error_code || anyErr.error_name || anyErr.error;
+    const msg = (anyErr.message || anyErr.error || '').toString();
+
+    const transientMarkers = [
+      'AWS_ERROR_MQTT_TIMEOUT',
+      'AWS_ERROR_MQTT_NO_CONNECTION',
+      'AWS_ERROR_MQTT_UNEXPECTED_HANGUP',
+      'UNEXPECTED_HANGUP',
+      'AWS_ERROR_MQTT_CONNECTION_DESTROYED',
+      'Time limit between request and response',
+      'timeout'
+    ];
+
+    return transientMarkers.some((m) => (code && String(code).includes(m)) || msg.includes(m));
+  }
+
+  /**
+   * Publishes an MQTT message with exponential backoff retries for transient failures.
+   *
+   * Retries occur for errors classified by `_isTransientMqttError`. Between attempts the delay grows exponentially with
+   * jitter to avoid thundering herds after broker recovery. If the connection is not currently marked as connected, a
+   * reconnect is attempted; if that fails, the connection is rebuilt (fresh credentials) before the next retry.
+   *
+   * On final failure (after maxAttempts) a {@link MqttPublishError} is thrown including the number of attempts and
+   * original error for higher-level handling.
+   *
+   * @remarks
+   * Retry options fields:
+   *
+   * - MaxAttempts: Maximum number of publish attempts before failing (default: 5).
+   * - BaseDelayMs: Base delay in milliseconds used for exponential backoff calculation (default: 500).
+   *
+   * @param connection - The active MQTT client connection used to send the publish.
+   * @param topic - The MQTT topic to publish to.
+   * @param payload - The serialized payload (binary buffer or Uint8Array).
+   * @param qos - The desired MQTT QoS level for the publish.
+   * @param opts - Retry options (defaults: maxAttempts=5, baseDelayMs=500).
+   * @returns A promise that resolves when the publish succeeds, or rejects with {@link MqttPublishError}.
+   */
+  private async _publishWithRetry(
+    connection: mqtt.MqttClientConnection,
+    topic: string,
+    payload: ArrayBuffer | Uint8Array,
+    qos: mqtt.QoS,
+    opts: MqttPublishOptions = {}
+  ): Promise<void> {
+    const maxAttempts = opts.maxAttempts ?? 5;
+    const baseDelayMs = opts.baseDelayMs ?? 500;
+
+    let attempt = 0;
+
+    while (true) {
+      attempt++;
+      try {
+        await connection.publish(topic, payload, qos);
+        return;
+      } catch (err) {
+        const isTransient = this._isTransientMqttError(err);
+
+        if (!isTransient || attempt >= maxAttempts) {
+          throw new MqttPublishError(`MQTT publish failed after ${attempt} attempts`, attempt, err);
+        }
+
+        // Apply jitter: delay is randomized between 75% and 125% of the base exponential backoff
+        const JITTER_MIN_FACTOR = 0.75;
+        const JITTER_RANGE = 0.5;
+        const delay = baseDelayMs * Math.pow(2, attempt - 1) * (JITTER_MIN_FACTOR + Math.random() * JITTER_RANGE);
+
+        this._logger.warn(
+          `Transient MQTT publish error on '${topic}' (attempt ${attempt}/${maxAttempts}). Retrying in ${Math.round(
+            delay
+          )}ms`
+        );
+
+        await new Promise((r) => setTimeout(r, delay));
+      }
+    }
+  }
+
   /**
    * Creates a new MQTT connection using AWS IoT WebSocket connections with Cognito credentials.
    *
    * @returns A promise that resolves to an active MQTT connection.
    * @throws {@link Error} When connection establishment fails.
    */
-  private async createMqttConnection(): Promise<mqtt.MqttClientConnection> {
-    const session = await this.getFreshSession();
+  private async _createMqttConnection(): Promise<mqtt.MqttClientConnection> {
+    const session = await this._getFreshSession();
     const credentialsProvider = fromCognitoIdentityPool({
       clientConfig: {
         region: AwsRegion
@@ -574,31 +715,144 @@ export class MysaApiClient {
     });
     const credentials = await credentialsProvider();
 
+    if (!credentials.expiration) {
+      throw new Error('MQTT credentials do not have an expiration time.');
+    }
+
+    this._mqttCredentialsExpiration = dayjs(credentials.expiration);
+
+    this._logger.debug(`MQTT credentials expiration: ${this._mqttCredentialsExpiration.format()}`);
+
+    if (!this._mqttCredentialsExpiration.isAfter(dayjs())) {
+      this._mqttCredentialsExpiration = undefined;
+      throw new Error('MQTT credentials are already expired.');
+    }
+
+    // Per-process stable client id. Random suffix avoids collisions with other running processes.
+    if (!this._mqttClientId) {
+      const username = this.session?.username ?? 'anon';
+      const usernameHash = hash('sha1', username);
+      this._mqttClientId = `mysa-js-sdk-${usernameHash}-${process.pid}-${getRandomClientId()}`;
+    }
+
     const builder = iot.AwsIotMqttConnectionConfigBuilder.new_with_websockets()
       .with_credentials(AwsRegion, credentials.accessKeyId, credentials.secretAccessKey, credentials.sessionToken)
       .with_endpoint(MqttEndpoint)
-      .with_client_id(`mysa-js-sdk-${dayjs().unix()}`) // Unique client ID
-      .with_clean_session(true)
+      .with_client_id(this._mqttClientId)
+      .with_clean_session(false)
       .with_keep_alive_seconds(30)
       .with_ping_timeout_ms(3000)
-      .with_protocol_operation_timeout_ms(60000);
+      .with_protocol_operation_timeout_ms(60000)
+      .with_reconnect_min_sec(1)
+      .with_reconnect_max_sec(30);
 
     const config = builder.build();
     const client = new mqtt.MqttClient();
     const connection = client.new_connection(config);
 
-    connection.on('connect', () => this._logger.debug('MQTT connect'));
-    connection.on('connection_success', () => this._logger.debug('MQTT connection_success'));
-    connection.on('connection_failure', (e) => this._logger.error('MQTT connection_failure', e));
-    connection.on('interrupt', (e) => this._logger.warn('MQTT interrupt', e));
-    connection.on('resume', (returnCode, sessionPresent) =>
-      this._logger.info(`MQTT resume returnCode=${returnCode} sessionPresent=${sessionPresent}`)
-    );
-    connection.on('error', (e) => this._logger.error('MQTT error', e));
+    connection.on('connect', () => {
+      this._logger.debug(`MQTT connect (clientId=${this._mqttClientId})`);
+    });
+
+    connection.on('connection_success', () => {
+      this._logger.debug(`MQTT connection_success (clientId=${this._mqttClientId})`);
+    });
+
+    connection.on('connection_failure', (e) => {
+      this._logger.error(`MQTT connection_failure (clientId=${this._mqttClientId})`, e);
+    });
+
+    connection.on('interrupt', async (e) => {
+      this._logger.warn(`MQTT interrupt (clientId=${this._mqttClientId})`, e);
+
+      // Track recent interrupts
+      const now = Date.now();
+
+      // Keep only last 60s
+      this._mqttInterrupts = this._mqttInterrupts.filter((t) => now - t < 60000);
+      this._mqttInterrupts.push(now);
+
+      const areCredentialsExpired = !(this._mqttCredentialsExpiration?.isAfter(dayjs()) ?? false);
+
+      if ((this._mqttInterrupts.length > 5 || areCredentialsExpired) && !this._mqttResetInProgress) {
+        this._mqttResetInProgress = true;
+
+        if (this._mqttInterrupts.length > 5) {
+          this._logger.warn(
+            `High interrupt rate (${this._mqttInterrupts.length}/60s). Possible clientId collision. Regenerating clientId and resetting connection...`
+          );
+        } else {
+          this._logger.warn(`Credentials expired. Regenerating clientId and resetting connection...`);
+        }
+
+        // Force new client id to escape collision; close current connection
+        this._mqttClientId = undefined;
+
+        this._mqttCredentialsExpiration = undefined;
+
+        // Clear interrupts
+        this._mqttInterrupts = [];
+
+        // Explicitly clear promise first to prevent reuse while disconnecting
+        // (publishers calling _getMqttConnection() will create a new one)
+        this._mqttConnectionPromise = undefined;
+
+        try {
+          await connection.disconnect();
+
+          try {
+            this._logger.debug('Old MQTT connection disconnected; establishing new connection...');
+            const newConnection = await this._getMqttConnection();
+
+            for (const deviceId of Array.from(this._realtimeDeviceIds.keys())) {
+              const topic = `/v1/dev/${deviceId}/out`;
+              this._logger.debug(`Re-subscribing to ${topic}`);
+              await newConnection.subscribe(topic, mqtt.QoS.AtLeastOnce, (_topic, payload) => {
+                this._processMqttMessage(payload);
+              });
+            }
+
+            this._logger.info('MQTT connection rebuilt successfully after interrupt storm or credentials expiration');
+          } catch (err) {
+            this._logger.error('Failed to re-subscribe after interrupt storm or credentials expiration', err);
+          }
+        } catch (error) {
+          this._logger.error('Error during MQTT reset', error);
+        } finally {
+          this._mqttResetInProgress = false;
+        }
+      }
+    });
+
+    connection.on('resume', async (returnCode, sessionPresent) => {
+      this._logger.info(
+        `MQTT resume returnCode=${returnCode} sessionPresent=${sessionPresent} clientId=${this._mqttClientId}`
+      );
+
+      if (!sessionPresent) {
+        this._logger.info('No session present, re-subscribing each device');
+        try {
+          for (const deviceId of Array.from(this._realtimeDeviceIds.keys())) {
+            const topic = `/v1/dev/${deviceId}/out`;
+            this._logger.debug(`Re-subscribing to ${topic}`);
+            await connection.subscribe(topic, mqtt.QoS.AtLeastOnce, (_topic, payload) => {
+              this._processMqttMessage(payload);
+            });
+          }
+        } catch (err) {
+          this._logger.error('Failed to re-subscribe after resume', err);
+        }
+      }
+    });
+
+    connection.on('error', (e) => {
+      this._logger.error(`MQTT error (clientId=${this._mqttClientId})`, e);
+    });
 
     connection.on('closed', () => {
       this._logger.info('MQTT connection closed');
       this._mqttConnectionPromise = undefined;
+      this._mqttCredentialsExpiration = undefined;
     });
 
     await connection.connect();
@@ -615,7 +869,7 @@ export class MysaApiClient {
    *
    * @param payload - The raw MQTT message payload to process.
    */
-  private processMqttMessage(payload: ArrayBuffer) {
+  private _processMqttMessage(payload: ArrayBuffer) {
     try {
       const parsedPayload = parseMqttPayload(payload);
 
@@ -653,13 +907,31 @@ export class MysaApiClient {
             });
             break;
 
-          case OutMessageType.DEVICE_STATE_CHANGE:
+          case OutMessageType.DEVICE_STATE_CHANGE: {
+            const modeMap: Record<number, MysaDeviceMode> = {
+              1: 'off',
+              2: 'auto',
+              3: 'heat',
+              4: 'cool',
+              5: 'fan_only',
+              6: 'dry'
+            };
+            const fanSpeedMap: Record<number, MysaFanSpeedMode> = {
+              1: 'auto',
+              3: 'low',
+              5: 'medium',
+              7: 'high',
+              8: 'max'
+            };
+
             this.emitter.emit('stateChanged', {
               deviceId: parsedPayload.src.ref,
-              mode: parsedPayload.body.state.md === 1 ? 'off' : parsedPayload.body.state.md === 3 ? 'heat' : undefined,
-              setPoint: parsedPayload.body.state.sp
+              mode: parsedPayload.body.state.md ? modeMap[parsedPayload.body.state.md] : undefined,
+              setPoint: parsedPayload.body.state.sp,
+              fanSpeed: parsedPayload.body.state.fn !== undefined ? fanSpeedMap[parsedPayload.body.state.fn] : undefined
             });
             break;
+          }
         }
       }
     } catch (error) {

src/api/MysaDeviceMode.ts

@@ -4,4 +4,11 @@
  * Defines the possible operational states that a Mysa thermostat or heating device can be set to. These modes control
  * the device's heating behavior and power consumption.
  */
-export type MysaDeviceMode = 'off' | 'heat';
+export type MysaDeviceMode = 'off' | 'heat' | 'cool' | 'dry' | 'fan_only' | 'auto';
+
+/**
+ * Union type representing the available fan speed modes for Mysa devices.
+ *
+ * Defines the possible fan speed states that a Mysa thermostat device can be set to.
+ */
+export type MysaFanSpeedMode = 'auto' | 'low' | 'medium' | 'high' | 'max';

src/api/events/StateChange.ts

@@ -1,4 +1,4 @@
-import { MysaDeviceMode } from '@/api/MysaDeviceMode';
+import { MysaDeviceMode, MysaFanSpeedMode } from '@/api/MysaDeviceMode';
 
 /**
  * Interface representing a device state change event for a Mysa device.
@@ -14,4 +14,6 @@ export interface StateChange {
   mode?: MysaDeviceMode;
   /** Current temperature setpoint after the state change */
   setPoint: number;
+  /** Optional fan speed (1 = auto, 3 = low, 5 = medium, 7 = high, 8 = max). AC only */
+  fanSpeed?: MysaFanSpeedMode;
 }

src/types/mqtt/in/ChangeDeviceState.ts

@@ -36,6 +36,8 @@ export interface ChangeDeviceState extends MsgPayload<InMessageType.CHANGE_DEVIC
         md?: number;
         /** Unknown, should always be -1 */
         tm: number;
+        /** Optional fan speed (1 = auto, 3 = low, 5 = medium, 7 = high, 8 = max). AC only */
+        fn?: number;
       }
     ];
     /**

src/types/mqtt/out/DeviceStateChange.ts

@@ -25,10 +25,12 @@ export interface DeviceStateChange extends MsgPayload<OutMessageType.DEVICE_STAT
       ho: number;
       /** Unknown */
       lk: number;
-      /** Device mode (1 = OFF, 3 = HEAT) */
+      /** Device mode (1 = OFF, 2 = AUTO, 3 = HEAT, 4 = COOL, 5 = FAN_ONLY, 6 = DRY) */
       md: number;
       /** Temperature setpoint */
       sp: number;
+      /** Optional fan speed (1 = auto, 3 = low, 5 = medium, 7 = high, 8 = max). AC only */
+      fn?: number;
     };
     /** Success indicator for the state change operation (1 = success, 0 = failure) */
     success: number;

src/types/rest/Devices.ts

@@ -10,9 +10,9 @@ export interface BrandInfo {
   /** Unique identifier for the brand */
   Id: number;
   /** Remote control model number for the AC device */
-  remoteModelNumber: string;
+  remoteModelNumber?: string;
   /** Original Equipment Manufacturer brand name */
-  OEMBrand: string;
+  OEMBrand?: string;
 }
 
 /**
@@ -56,55 +56,55 @@ export interface ModeObj {
  */
 export interface DeviceBase {
   /** Button digital input configuration value */
-  ButtonDI: number;
+  ButtonDI?: number;
   /** Maximum current rating as a string value */
-  MaxCurrent: string;
+  MaxCurrent?: string;
   /** Device model identifier string */
   Model: string;
   /** Button average value configuration */
-  ButtonAVE: number;
+  ButtonAVE?: number;
   /** Operating voltage of the device */
-  Voltage: number;
+  Voltage?: number;
   /** Button polling interval configuration */
-  ButtonPolling: number;
+  ButtonPolling?: number;
   /** Minimum brightness level (0-100) */
-  MinBrightness: number;
+  MinBrightness?: number;
   /** User-assigned device name */
-  Name: string;
+  Name?: string;
   /** Button low power mode configuration */
-  ButtonLowPower: number;
+  ButtonLowPower?: number;
   /** Type of heater controlled by the device */
-  HeaterType: string;
+  HeaterType?: string;
   /** Button repeat delay configuration in milliseconds */
-  ButtonRepeatDelay: number;
+  ButtonRepeatDelay?: number;
   /** Button repeat start delay configuration in milliseconds */
-  ButtonRepeatStart: number;
+  ButtonRepeatStart?: number;
   /** Display animation style setting */
-  Animation: string;
+  Animation?: string;
   /** Maximum brightness level (0-100) */
-  MaxBrightness: number;
+  MaxBrightness?: number;
   /** Array of user IDs allowed to control this device */
-  AllowedUsers: string[];
+  AllowedUsers?: string[];
   /** Current button state indicator */
-  ButtonState: string;
+  ButtonState?: string;
   /** Home identifier that this device belongs to */
-  Home: string;
+  Home?: string;
   /** Button sensitivity threshold configuration */
-  ButtonThreshold: number;
+  ButtonThreshold?: number;
   /** Data format version used by the device */
-  Format: string;
+  Format?: string;
   /** Time zone setting for the device */
-  TimeZone: string;
+  TimeZone?: string;
   /** Unix timestamp of when device was last paired */
-  LastPaired: number;
+  LastPaired?: number;
   /** Minimum temperature setpoint allowed */
-  MinSetpoint: number;
+  MinSetpoint?: number;
   /** Current operating mode of the device */
-  Mode: ModeObj;
+  Mode?: ModeObj;
   /** User ID of the device owner */
-  Owner: string;
+  Owner?: string;
   /** Maximum temperature setpoint allowed */
-  MaxSetpoint: number;
+  MaxSetpoint?: number;
   /** Unique device identifier */
   Id: string;
   /** Optional zone assignment for the device */

src/types/rest/States.ts

@@ -13,43 +13,45 @@ export interface DeviceState {
   /** Overall timestamp for the device state */
   Timestamp: number;
   /** Time the device has been on */
-  OnTime: TimestampedValue<number>;
+  OnTime?: TimestampedValue<number>;
   /** Temperature set point */
-  SetPoint: TimestampedValue<number>;
+  SetPoint?: TimestampedValue<number>;
   /** Display brightness level */
-  Brightness: TimestampedValue<number>;
+  Brightness?: TimestampedValue<number>;
   /** Schedule mode setting */
-  ScheduleMode: TimestampedValue<number>;
+  ScheduleMode?: TimestampedValue<number>;
   /** Hold time setting */
-  HoldTime: TimestampedValue<number>;
+  HoldTime?: TimestampedValue<number>;
   /** Wi-Fi signal strength */
-  Rssi: TimestampedValue<number>;
+  Rssi?: TimestampedValue<number>;
   /** Thermostat mode */
-  TstatMode: TimestampedValue<number>;
+  TstatMode?: TimestampedValue<number>;
   /** Available heap memory */
-  FreeHeap: TimestampedValue<number>;
+  FreeHeap?: TimestampedValue<number>;
   /** Sensor temperature reading */
-  SensorTemp: TimestampedValue<number>;
+  SensorTemp?: TimestampedValue<number>;
   /** Current mode */
-  Mode: TimestampedValue<number>;
+  Mode?: TimestampedValue<number>;
   /** Voltage measurement */
-  Voltage: TimestampedValue<number>;
+  Voltage?: TimestampedValue<number>;
   /** Temperature corrected for calibration */
-  CorrectedTemp: TimestampedValue<number>;
+  CorrectedTemp?: TimestampedValue<number>;
   /** Duty cycle percentage */
-  Duty: TimestampedValue<number>;
+  Duty?: TimestampedValue<number>;
   /** Heat sink temperature */
-  HeatSink: TimestampedValue<number>;
+  HeatSink?: TimestampedValue<number>;
   /** Time the device has been off */
-  OffTime: TimestampedValue<number>;
+  OffTime?: TimestampedValue<number>;
   /** Connection status */
-  Connected: TimestampedValue<boolean>;
+  Connected?: TimestampedValue<boolean>;
   /** Current consumption */
-  Current: TimestampedValue<number>;
+  Current?: TimestampedValue<number>;
   /** Humidity reading */
-  Humidity: TimestampedValue<number>;
+  Humidity?: TimestampedValue<number>;
   /** Lock status */
-  Lock: TimestampedValue<number>;
+  Lock?: TimestampedValue<number>;
+  /** Fan speed */
+  FanSpeed?: TimestampedValue<number>;
 }
 
 /**