diff --git a/bosdyn-client/channel.js b/bosdyn-client/channel.js
index eeb9faa..d2a7462 100644
--- a/bosdyn-client/channel.js
+++ b/bosdyn-client/channel.js
@@ -1,10 +1,11 @@
 'use strict';
 
+const process = require('node:process');
 const { Buffer } = require('node:buffer');
+
 const grpc = require('@grpc/grpc-js');
 
 const {
-  RpcError,
   ClientCancelledOperationError,
   InvalidAppTokenError,
   InvalidClientCertificateError,
@@ -13,15 +14,18 @@ const {
   PermissionDeniedError,
   ProxyConnectionError,
   ResponseTooLargeError,
+  RetryableUnavailableError,
+  RpcError,
   ServiceFailedDuringExecutionError,
   ServiceUnavailableError,
   TimedOutError,
+  TooManyRequestsError,
+  TransientFailureError,
   UnableToConnectToRobotError,
   UnauthenticatedError,
-  UnknownDnsNameError,
   UnimplementedError,
-  TransientFailureError,
-} = require('./exceptions.js');
+  UnknownDnsNameError,
+} = require('./exceptions');
 
 /**
  * Set default max message length for sending and receiving to 100MB. This value is used when
@@ -35,23 +39,19 @@ const DEFAULT_MAX_MESSAGE_LENGTH = 100 * 1024 ** 2;
 /**
  * Plugin to refresh access token.
  * @param {Function} token_cb Callable that returns an Object<app_token, user_token>
- * @param {boolean} add_app_token Whether to include an app token in the metadata.
- * This is necessary for compatibility with old robot software.
+ * @param {boolean} [add_app_token] Deprecated.
  * @returns {Function}
  */
-function RefreshingAccessTokenAuthMetadataPlugin(token_cb, add_app_token) {
+function RefreshingAccessTokenAuthMetadataPlugin(token_cb, add_app_token = null) {
   const _token_cb = token_cb;
-  const _add_app_token = add_app_token;
+  if (add_app_token !== null) {
+    process.emitWarning('add_app_token is deprecated for RefreshingAccessTokenAuthMetadataPlugin.', 'Do not set it');
+  }
 
   return function setMetadata(context, callback) {
-    const { app_token, user_token } = _token_cb();
+    const { user_token } = _token_cb();
     const metadata = new grpc.Metadata();
-    if (_add_app_token) {
-      metadata.set('authorization', `Bearer ${user_token}`);
-      metadata.set('x-bosdyn-apptoken', app_token);
-    } else {
-      metadata.set('authorization', `Bearer ${user_token}`);
-    }
+    metadata.set('authorization', `Bearer ${user_token}`);
     return callback(null, metadata);
   };
 }
@@ -60,11 +60,14 @@ function RefreshingAccessTokenAuthMetadataPlugin(token_cb, add_app_token) {
  * Returns credentials for establishing a secure channel. Uses previously set values on the linked Sdk and this.
  * @param {string|Buffer} cert The certificate to create channel credentials.
  * @param {Function} token_cb Callable that returns an Object<app_token, user_token>
- * @param {boolean} add_app_token Whether to include an app token in the metadata.
- * This is necessary for compatibility with old robot software.
+ * @param {boolean} add_app_token Deprecated.
  * @returns {Object}
  */
-function create_secure_channel_creds(cert, token_cb, add_app_token) {
+function create_secure_channel_creds(cert, token_cb, add_app_token = null) {
+  if (add_app_token !== null) {
+    process.emitWarning('add_app_token is deprecated for create_secure_channel_creds.', 'Do not set it');
+  }
+
   cert = Buffer.concat([Buffer.from(cert), Buffer.from('\0')]);
   const transport_creds = grpc.credentials.createSsl(cert);
   const plugin = RefreshingAccessTokenAuthMetadataPlugin(token_cb, add_app_token);
@@ -113,8 +116,8 @@ function create_insecure_channel(address, port, authority = null, options = {})
 
 * The list contains the values for max allowed message length for both sending and
 * receiving. If no values are provided, the default values of 100 MB are used.
-* @param {?number} [max_send_message_length=104857600] Max message length allowed for message to send.
-* @param {?number} [max_receive_message_length=104857600] Max message length allowed for message to receive.
+* @param {?number} [max_send_message_length=104_857_600] Max message length allowed for message to send.
+* @param {?number} [max_receive_message_length=104_857_600] Max message length allowed for message to receive.
 * @returns {Object} Object with values for channel options.
 */
 function generate_channel_options(max_send_message_length = null, max_receive_message_length = null) {
@@ -176,6 +179,15 @@ function translate_exception(rpc_error) {
   }
 
   if (code === grpc.status.UNAVAILABLE) {
+    if (msg.includes('Socket closed') || msg.includes('Connection reset by peer')) {
+      return new RetryableUnavailableError(msg);
+    }
+    if (msg.includes(502)) {
+      return new ServiceUnavailableError(msg);
+    }
+    if (msg.includes(429)) {
+      return new TooManyRequestsError(msg);
+    }
     return new UnableToConnectToRobotError(msg);
   }
 
diff --git a/bosdyn-client/robot.js b/bosdyn-client/robot.js
index c8fd667..6f3b4e8 100644
--- a/bosdyn-client/robot.js
+++ b/bosdyn-client/robot.js
@@ -139,6 +139,10 @@ class Robot {
     }
   }
 
+  get host() {
+    return this._name;
+  }
+
   _get_token_id(username) {
     return `${this.serial_number}.${username}`;
   }
@@ -216,19 +220,12 @@ class Robot {
     return this._robot_id;
   }
 
-  async _should_send_app_token_on_each_request() {
-    const robot_id = await this.get_cached_robot_id();
-    const robot_software_version = robot_id.getSoftwareRelease().getVersion();
-    if (robot_software_version.getMajorVersion() <= 1 && robot_software_version.getMinorVersion() <= 1) return true;
-    return false;
-  }
-
   /**
    * Verify the right information exists before calling the ensure_secure_channel method.
    * @param  {string}  service_name Name of the service in the directory.
    * @param  {boolean} [secure=true] Create a secure channel or not.
    * @param  {Array} options Options of the grpc channel.
-   * @returns {Promise<*>|*} Existing channel if found, or newly created channel if not found.
+   * @returns {Promise<*>} Existing channel if found, or newly created channel if not found.
    */
   async ensure_channel(service_name, secure = true, options = []) {
     const option = options.length ? options.map(x => x[0]) : null;
@@ -260,16 +257,13 @@ class Robot {
       : this.ensure_insecure_channel(authority, options);
   }
 
-  async ensure_secure_channel(authority, skip_app_token_check = false, options = []) {
+  ensure_secure_channel(authority, skip_app_token_check = false, options = []) {
     if (authority in this.channels_by_authority) return this.channels_by_authority[authority];
 
-    const should_send_app_token = skip_app_token_check ? false : await this._should_send_app_token_on_each_request();
-
-    const creds = channel.create_secure_channel_creds(
-      this.cert,
-      () => ({ app_token: this.app_token, user_token: this.user_token }),
-      should_send_app_token,
-    );
+    const creds = channel.create_secure_channel_creds(this.cert, () => ({
+      app_token: this.app_token,
+      user_token: this.user_token,
+    }));
     const channelData = channel.create_secure_channel(
       this.address,
       _DEFAULT_SECURE_CHANNEL_PORT,
@@ -287,8 +281,8 @@ class Robot {
   ensure_insecure_channel(authority, options = []) {
     if (authority in this.channels_by_authority) return this.channels_by_authority[authority];
     const channelData = channel.create_insecure_channel(this.address, _DEFAULT_SECURE_CHANNEL_PORT, authority, options);
-    this.logger.debug(
-      `[ROBOT] Created channel to ${this.address} at port ${_DEFAULT_SECURE_CHANNEL_PORT} with authority ${authority}`,
+    this.logger.warn(
+      `[ROBOT] Created insecure channel to ${this.address} at port ${_DEFAULT_SECURE_CHANNEL_PORT} with authority ${authority}`,
     );
     this.channels_by_authority[authority] = channelData;
     return channelData;
@@ -297,7 +291,7 @@ class Robot {
   async authenticate(username, password, timeout) {
     console.log('Pensez à modifier authenticate dans le fichier robot.js');
     const default_service_name = AuthClient.default_service_name;
-    const auth_channel = this.ensure_insecure_channel(this._bootstrap_service_authorities[default_service_name]);
+    const auth_channel = this.ensure_secure_channel(this._bootstrap_service_authorities[default_service_name]);
     const auth_client = await this.ensure_client(default_service_name, auth_channel);
     const user_token = await auth_client.auth(username, password, this.app_token, { timeout });
     this.update_user_token(user_token, username);