diff --git a/signalk-client/apps-api.ts b/signalk-client/apps-api.ts
index f099f9e..6470c49 100644
--- a/signalk-client/apps-api.ts
+++ b/signalk-client/apps-api.ts
@@ -1,11 +1,11 @@
 /** Signal K server Apps API */
 export class SignalKApps {
   /** apps API endpoint. */
-  public endpoint = "";
+  public endpoint = '';
 
   /** Return List of installed apps. */
   async list() {
-    const ep = this.endpoint.indexOf("webapps") === -1
+    const ep = this.endpoint.indexOf('webapps') === -1
       ? `${this.endpoint}list`
       : this.endpoint;
     const response = await fetch(ep);
diff --git a/signalk-client/http-api.ts b/signalk-client/http-api.ts
index edc3a2a..ab23a51 100644
--- a/signalk-client/http-api.ts
+++ b/signalk-client/http-api.ts
@@ -1,18 +1,18 @@
-import { Alarm, AlarmType, Path } from "./utils.ts";
-import { SKServer } from "./signalk-client.ts";
-import { debug } from "./mod.ts";
+import { Alarm, AlarmType, Path } from './utils.ts';
+import { SKServer } from './signalk-client.ts';
+import { debug } from './mod.ts';
 
 /** Signal K HTTP API operations */
 export class SignalKHttp {
   /** Authentication token
    * @private
    */
-  private _token = "";
+  private _token = '';
 
   /** Signal K server information */
-  public server: SKServer = { version: "", id: "" };
+  public server: SKServer = { version: '', id: '' };
   /** Connection endpoint */
-  public endpoint = "";
+  public endpoint = '';
   /** API version to use */
   public version = 1;
 
@@ -62,14 +62,14 @@ export class SignalKHttp {
     }
     let ep: string;
     let path: string;
-    if (typeof p1 === "number") {
-      ep = this.endpoint.replace(new RegExp("/v[0-9]+/"), `/v${p1}/`);
+    if (typeof p1 === 'number') {
+      ep = this.endpoint.replace(new RegExp('/v[0-9]+/'), `/v${p1}/`);
       path = Path.dotToSlash(p2);
     } else {
       ep = this.endpoint;
       path = Path.dotToSlash(p1);
     }
-    if (path[0] === "/") {
+    if (path[0] === '/') {
       path = path.slice(1);
     }
     const url = `${ep}${path}`;
@@ -114,8 +114,8 @@ export class SignalKHttp {
     let path: string;
     let value;
     let msg;
-    if (typeof p1 === "number") {
-      ep = this.endpoint.replace(new RegExp("/v[0-9]+/"), `/v${p1}/`);
+    if (typeof p1 === 'number') {
+      ep = this.endpoint.replace(new RegExp('/v[0-9]+/'), `/v${p1}/`);
       path = Path.dotToSlash(p2);
       value = p3;
       msg = this.parseApiPut(p1, value);
@@ -125,19 +125,19 @@ export class SignalKHttp {
       value = p2;
       msg = this.parseApiPut(this.version, value);
     }
-    if (path[0] === "/") {
+    if (path[0] === '/') {
       path = path.slice(1);
     }
 
     const url = `${ep}${path}`;
     debug(`put ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options: RequestInit = {
-      method: "PUT",
+      method: 'PUT',
       headers: headers,
       body: JSON.stringify(msg),
     };
@@ -176,32 +176,32 @@ export class SignalKHttp {
     let context: string;
     let value;
     let msg;
-    if (typeof p1 === "number") {
-      ep = this.endpoint.replace(new RegExp("/v[0-9]+/"), `/v${p1}/`);
-      context = p2 ? `${Path.contextToPath(p2)}/` : "";
+    if (typeof p1 === 'number') {
+      ep = this.endpoint.replace(new RegExp('/v[0-9]+/'), `/v${p1}/`);
+      context = p2 ? `${Path.contextToPath(p2)}/` : '';
       path = Path.dotToSlash(p3);
       value = p4;
       msg = this.parseApiPut(p1, value);
     } else {
       ep = this.endpoint;
-      context = p1 ? `${Path.contextToPath(p1)}/` : "";
+      context = p1 ? `${Path.contextToPath(p1)}/` : '';
       path = Path.dotToSlash(p2);
       value = p3;
       msg = this.parseApiPut(this.version, value);
     }
-    if (path[0] === "/") {
+    if (path[0] === '/') {
       path = path.slice(1);
     }
 
     const url = ep + context + path;
     debug(`put ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options: RequestInit = {
-      method: "PUT",
+      method: 'PUT',
       headers: headers,
       body: JSON.stringify(msg),
     };
@@ -226,8 +226,8 @@ export class SignalKHttp {
     let ep: string;
     let path: string;
     let value;
-    if (typeof p1 === "number") {
-      ep = this.endpoint.replace(new RegExp("/v[0-9]+/"), `/v${p1}/`);
+    if (typeof p1 === 'number') {
+      ep = this.endpoint.replace(new RegExp('/v[0-9]+/'), `/v${p1}/`);
       path = Path.dotToSlash(p2);
       value = p3;
     } else {
@@ -235,18 +235,18 @@ export class SignalKHttp {
       path = Path.dotToSlash(p1);
       value = p2;
     }
-    if (path[0] === "/") {
+    if (path[0] === '/') {
       path = path.slice(1);
     }
     const url = `${ep}${path}`;
     debug(`post ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options: RequestInit = {
-      method: "POST",
+      method: 'POST',
       headers: headers,
       body: JSON.stringify(value),
     };
@@ -268,25 +268,25 @@ export class SignalKHttp {
     }
     let ep: string;
     let path: string;
-    if (typeof p1 === "number") {
-      ep = this.endpoint.replace(new RegExp("/v[0-9]+/"), `/v${p1}/`);
+    if (typeof p1 === 'number') {
+      ep = this.endpoint.replace(new RegExp('/v[0-9]+/'), `/v${p1}/`);
       path = Path.dotToSlash(p2);
     } else {
       ep = this.endpoint;
       path = Path.dotToSlash(p1);
     }
-    if (path[0] === "/") {
+    if (path[0] === '/') {
       path = path.slice(1);
     }
     const url = `${ep}${path}`;
     debug(`get ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options: RequestInit = {
-      method: "DELETE",
+      method: 'DELETE',
       headers: headers,
     };
     return await fetch(url, options);
@@ -304,10 +304,10 @@ export class SignalKHttp {
    */
   raiseAlarm(context: string, name: string, alarm: Alarm): Promise<Response>;
   raiseAlarm(context: string, type: AlarmType, alarm: Alarm): Promise<Response>;
-  raiseAlarm(context = "*", alarmId: string | AlarmType, alarm: Alarm) {
+  raiseAlarm(context = '*', alarmId: string | AlarmType, alarm: Alarm) {
     let path: string;
-    if (typeof alarmId === "string") {
-      path = alarmId.indexOf("notifications.") === -1
+    if (typeof alarmId === 'string') {
+      path = alarmId.indexOf('notifications.') === -1
         ? `notifications.${alarmId}`
         : alarmId;
     } else {
@@ -320,8 +320,8 @@ export class SignalKHttp {
    * @param context Signal K context
    * @param name Alarm name.
    */
-  clearAlarm(context = "*", name: string): Promise<Response> {
-    const path = name.indexOf("notifications.") === -1
+  clearAlarm(context = '*', name: string): Promise<Response> {
+    const path = name.indexOf('notifications.') === -1
       ? `notifications.${name}`
       : name;
     return this.putWithContext(context, path, null);
diff --git a/signalk-client/mod.ts b/signalk-client/mod.ts
index 606eead..1bd76be 100644
--- a/signalk-client/mod.ts
+++ b/signalk-client/mod.ts
@@ -2,11 +2,11 @@
  * Signal K Client
  *****************************/
 
-export * from "./signalk-client.ts";
-export * from "./utils.ts";
-export * from "./stream-api.ts";
-export * from "./http-api.ts";
-export * from "./apps-api.ts";
+export * from './signalk-client.ts';
+export * from './utils.ts';
+export * from './stream-api.ts';
+export * from './http-api.ts';
+export * from './apps-api.ts';
 
 let _isDev = false;
 
@@ -18,6 +18,6 @@ export function setDev(val?: boolean) {
 /** Print debug messages to console (if development mode) */
 export function debug(...args: any[]) {
   if (_isDev) {
-    console.log(`%cSignalKClient: `, "color: yellow", ...args);
+    console.log(`%cSignalKClient: `, 'color: yellow', ...args);
   }
 }
diff --git a/signalk-client/signalk-client.ts b/signalk-client/signalk-client.ts
index 8e03400..54547e4 100644
--- a/signalk-client/signalk-client.ts
+++ b/signalk-client/signalk-client.ts
@@ -1,8 +1,8 @@
-import { SignalKHttp } from "./http-api.ts";
-import { SignalKStream } from "./stream-api.ts";
-import { SignalKApps } from "./apps-api.ts";
-import { Message, Path } from "./utils.ts";
-import { debug } from "./mod.ts";
+import { SignalKHttp } from './http-api.ts';
+import { SignalKStream } from './stream-api.ts';
+import { SignalKApps } from './apps-api.ts';
+import { Message, Path } from './utils.ts';
+import { debug } from './mod.ts';
 
 interface Server_Info {
   endpoints: { [key: string]: EndPoint };
@@ -12,8 +12,8 @@ interface Server_Info {
 
 interface EndPoint {
   version: string;
-  "signalk-http": string;
-  "signalk-ws": string;
+  'signalk-http': string;
+  'signalk-ws': string;
 }
 
 /** Signal K Server information */
@@ -34,15 +34,15 @@ interface PlaybackOptions {
 }
 
 interface JSON_Patch {
-  op: "add" | "replace" | "remove" | "copy" | "move" | "test";
+  op: 'add' | 'replace' | 'remove' | 'copy' | 'move' | 'test';
   path: string;
   value: unknown;
 }
 
 /** Application data contexts */
 export enum APPDATA_CONTEXT {
-  USER = "user",
-  GLOBAL = "global",
+  USER = 'user',
+  GLOBAL = 'global',
 }
 
 /** Signal K Client class */
@@ -50,7 +50,7 @@ export class SignalKClient {
   /** Signal K server hostname / ip address.
    * @private
    */
-  private hostname = "localhost";
+  private hostname = 'localhost';
   /** Port to connect on.
    * @private
    */
@@ -58,17 +58,17 @@ export class SignalKClient {
   /** Protocol to use http / https.
    * @private
    */
-  private protocol = "";
+  private protocol = '';
 
   /** Signal K API version to use
    * @private
    */
-  private _version = "v1";
+  private _version = 'v1';
 
   /** Authentication token value
    * @private
    */
-  private _token = ""; // token for when security is enabled on the server
+  private _token = ''; // token for when security is enabled on the server
 
   /** endpoints to fallback to if hello response is not received.
    * @private
@@ -76,20 +76,20 @@ export class SignalKClient {
   private fallbackEndpoints: HelloResponse = {
     endpoints: {
       v1: {
-        version: "1.0.0",
-        "signalk-http": "",
-        "signalk-ws": "",
+        version: '1.0.0',
+        'signalk-http': '',
+        'signalk-ws': '',
       },
     },
-    server: { id: "fallback", version: "1.43.0" },
+    server: { id: 'fallback', version: '1.43.0' },
   };
 
   /** Server information block */
   public server: Server_Info = {
     endpoints: {},
     info: {
-      version: "",
-      id: "",
+      version: '',
+      id: '',
     },
     apiVersions: [],
   };
@@ -111,7 +111,7 @@ export class SignalKClient {
    * @param val Major version number of API. e.g. 1
    */
   set version(val: number) {
-    const v: string = "v" + val;
+    const v: string = 'v' + val;
     if (this.server.apiVersions.length === 0) {
       this._version = v;
       debug(`Signal K api version set to: ${v}`);
@@ -175,19 +175,19 @@ export class SignalKClient {
   ) {
     this.hostname = hostname ? hostname : this.hostname;
     if (useSSL) {
-      this.protocol = "https";
+      this.protocol = 'https';
       this.port = port || 443;
     } else {
-      this.protocol = "http";
+      this.protocol = 'http';
       this.port = port || 80;
     }
     const httpUrl = `${this.protocol}://${this.hostname}:${this.port}`;
-    const wsUrl = `${useSSL ? "wss" : "ws"}://${this.hostname}:${this.port}`;
+    const wsUrl = `${useSSL ? 'wss' : 'ws'}://${this.hostname}:${this.port}`;
     this.fallbackEndpoints.endpoints.v1[
-      "signalk-http"
+      'signalk-http'
     ] = `${httpUrl}/signalk/v1/api/`;
     this.fallbackEndpoints.endpoints.v1[
-      "signalk-ws"
+      'signalk-ws'
     ] = `${wsUrl}/signalk/v1/stream`;
   }
 
@@ -204,7 +204,7 @@ export class SignalKClient {
     useSSL = false,
   ): Promise<{ [key: string]: unknown }> {
     this.init(hostname, port, useSSL);
-    return this.get("/signalk");
+    return this.get('/signalk');
   }
 
   /** connect to server (endpoint discovery) and DO NOT open Stream
@@ -217,7 +217,7 @@ export class SignalKClient {
     port = 3000,
     useSSL = false,
   ): Promise<boolean> {
-    debug("Contacting Signal K server.........");
+    debug('Contacting Signal K server.........');
     try {
       const response: unknown = await this.hello(hostname, port, useSSL);
       // ** discover endpoints **
@@ -261,7 +261,7 @@ export class SignalKClient {
     hostname: string = this.hostname,
     port = 3000,
     useSSL = false,
-    subscribe = "",
+    subscribe = '',
   ): Promise<boolean> {
     return new Promise((resolve, reject) => {
       this.connect(hostname, port, useSSL)
@@ -297,7 +297,7 @@ export class SignalKClient {
       this.connect(hostname, port, useSSL)
         .then(() => {
           // ** connect to playback api at preferred version else fall back to default version
-          this.openPlayback("", options, this._token);
+          this.openPlayback('', options, this._token);
           resolve(true);
         })
         .catch((e) => {
@@ -316,12 +316,12 @@ export class SignalKClient {
     subscribe?: string,
     token?: string,
   ): boolean {
-    debug("openStream.........");
+    debug('openStream.........');
     if (!url) {
       // connect to stream api at discovered endpoint
       url = this.resolveStreamEndpoint();
       if (!url) {
-        throw new Error("Server has no advertised Stream endpoints!");
+        throw new Error('Server has no advertised Stream endpoints!');
       }
     }
     this.stream.open(url, subscribe, token);
@@ -338,24 +338,24 @@ export class SignalKClient {
     options?: PlaybackOptions,
     token?: string,
   ): boolean {
-    debug("openPlayback.........");
+    debug('openPlayback.........');
     if (!url) {
       // connect to stream api at discovered endpoint
       url = this.resolveStreamEndpoint();
       if (!url) {
-        throw new Error("Server has no advertised Stream endpoints!");
+        throw new Error('Server has no advertised Stream endpoints!');
       }
-      url = url.replace("stream", "playback");
+      url = url.replace('stream', 'playback');
     }
-    let pb = "";
-    let subscribe: string | undefined = "";
-    if (options && typeof options === "object") {
+    let pb = '';
+    let subscribe: string | undefined = '';
+    if (options && typeof options === 'object') {
       pb += options.startTime
-        ? "?startTime=" +
-          options.startTime.slice(0, options.startTime.indexOf(".")) +
-          "Z"
-        : "";
-      pb += options.playbackRate ? `&playbackRate=${options.playbackRate}` : "";
+        ? '?startTime=' +
+          options.startTime.slice(0, options.startTime.indexOf('.')) +
+          'Z'
+        : '';
+      pb += options.playbackRate ? `&playbackRate=${options.playbackRate}` : '';
       subscribe = options.subscribe ? options.subscribe : undefined;
     }
     this.stream.open(url + pb, subscribe, token);
@@ -369,12 +369,12 @@ export class SignalKClient {
     if (this.proxied) {
       this.server.endpoints = this.fallbackEndpoints.endpoints;
     } else {
-      this.server.endpoints = response && response["endpoints"]
-        ? response["endpoints"]
+      this.server.endpoints = response && response['endpoints']
+        ? response['endpoints']
         : this.fallbackEndpoints.endpoints;
     }
-    this.server.info = response && response["server"]
-      ? response["server"]
+    this.server.info = response && response['server']
+      ? response['server']
       : this.fallbackEndpoints.server;
     this.server.apiVersions = this.server.endpoints
       ? Object.keys(this.server.endpoints)
@@ -386,42 +386,42 @@ export class SignalKClient {
 
   /** Return signalk apps API url */
   private resolveAppsEndpoint(): string {
-    return this.resolveHttpEndpoint().replace("api", "apps");
+    return this.resolveHttpEndpoint().replace('api', 'apps');
   }
 
   /** Return preferred WS stream url */
   private resolveStreamEndpoint(): string {
     if (
       this.server.endpoints[this._version] &&
-      this.server.endpoints[this._version]["signalk-ws"]
+      this.server.endpoints[this._version]['signalk-ws']
     ) {
       debug(`Connecting endpoint version: ${this._version}`);
-      return `${this.server.endpoints[this._version]["signalk-ws"]}`;
+      return `${this.server.endpoints[this._version]['signalk-ws']}`;
     } else if (
-      this.server.endpoints["v1"] &&
-      this.server.endpoints["v1"]["signalk-ws"]
+      this.server.endpoints['v1'] &&
+      this.server.endpoints['v1']['signalk-ws']
     ) {
       debug(`Connection falling back to: v1`);
-      return `${this.server.endpoints["v1"]["signalk-ws"]}`;
+      return `${this.server.endpoints['v1']['signalk-ws']}`;
     } else {
-      return "";
+      return '';
     }
   }
 
   /** Return signalk-http endpoint url */
   private resolveHttpEndpoint(): string {
-    let url = "";
+    let url = '';
     if (this.server.endpoints[this._version]) {
       // ** connection made
       // ** connect to http endpoint at prescribed version else fall back to default version
-      if (this.server.endpoints[this._version]["signalk-http"]) {
-        url = `${this.server.endpoints[this._version]["signalk-http"]}`;
+      if (this.server.endpoints[this._version]['signalk-http']) {
+        url = `${this.server.endpoints[this._version]['signalk-http']}`;
       } else {
-        url = `${this.server.endpoints["v1"]["signalk-http"]}`;
+        url = `${this.server.endpoints['v1']['signalk-http']}`;
       }
     } else {
       const msg =
-        "No current connection http endpoint service! Use connect() to establish a connection.";
+        'No current connection http endpoint service! Use connect() to establish a connection.';
       debug(msg);
     }
     return url;
@@ -431,8 +431,8 @@ export class SignalKClient {
   private disconnectedFromServer() {
     this.server.endpoints = {};
     this.server.info = {
-      version: "",
-      id: "",
+      version: '',
+      id: '',
     };
     this.server.apiVersions = [];
   }
@@ -441,7 +441,7 @@ export class SignalKClient {
    * @param path Signal K path.
    */
   async get(path: string): Promise<{ [key: string]: unknown }> {
-    if (path && path.length > 0 && path[0] === "/") {
+    if (path && path.length > 0 && path[0] === '/') {
       path = path.slice(1);
     }
     const url = `${this.protocol}://${this.hostname}:${this.port}/${
@@ -468,13 +468,13 @@ export class SignalKClient {
     }`;
 
     debug(`put ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options: RequestInit = {
-      method: "PUT",
+      method: 'PUT',
       headers: headers,
       body: JSON.stringify(value),
     };
@@ -486,7 +486,7 @@ export class SignalKClient {
    * @param value Value to apply.
    */
   async post(path: string, value: unknown): Promise<Response> {
-    if (path && path.length > 0 && path[0] === "/") {
+    if (path && path.length > 0 && path[0] === '/') {
       path = path.slice(1);
     }
     const url = `${this.protocol}://${this.hostname}:${this.port}/${
@@ -494,13 +494,13 @@ export class SignalKClient {
     }`;
 
     debug(`post ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options: RequestInit = {
-      method: "POST",
+      method: 'POST',
       headers: headers,
       body: JSON.stringify(value),
     };
@@ -515,17 +515,17 @@ export class SignalKClient {
     username: string,
     password: string,
   ): Promise<{ ok: boolean; status: number; token: string }> {
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     const url =
       `${this.protocol}://${this.hostname}:${this.port}/signalk/${this._version}/auth/login`;
 
     debug(`post ${url}`);
 
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
     const options = {
-      method: "POST",
+      method: 'POST',
       headers: headers,
       body: JSON.stringify({ username: username, password: password }),
     };
@@ -538,14 +538,14 @@ export class SignalKClient {
     const result = {
       ok: response.ok,
       status: response.status,
-      token: "",
+      token: '',
     };
     if (response.ok) {
-      const cookies = response.headers.get("set-cookie")?.split(";");
+      const cookies = response.headers.get('set-cookie')?.split(';');
       cookies?.forEach((c) => {
-        if (c.indexOf("JAUTHENTICATION") !== -1) {
-          this.authToken = c.split("=")[1];
-          debug("authToken: ", this._token);
+        if (c.indexOf('JAUTHENTICATION') !== -1) {
+          this.authToken = c.split('=')[1];
+          debug('authToken: ', this._token);
           result.token = this._token;
         }
       });
@@ -559,13 +559,13 @@ export class SignalKClient {
       `${this.protocol}://${this.hostname}:${this.port}/signalk/${this._version}/auth/validate`;
 
     debug(`post ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options = {
-      method: "POST",
+      method: 'POST',
       headers: headers,
       body: null,
     };
@@ -575,14 +575,14 @@ export class SignalKClient {
     const result = {
       ok: response.ok,
       status: response.status,
-      token: "",
+      token: '',
     };
     if (response.ok) {
-      const cookies = response.headers.get("set-cookie")?.split(";");
+      const cookies = response.headers.get('set-cookie')?.split(';');
       cookies?.forEach((c) => {
-        if (c.indexOf("JAUTHENTICATION") !== -1) {
-          this.authToken = c.split("=")[1];
-          debug("authToken: ", this._token);
+        if (c.indexOf('JAUTHENTICATION') !== -1) {
+          this.authToken = c.split('=')[1];
+          debug('authToken: ', this._token);
           result.token = this._token;
         }
       });
@@ -596,13 +596,13 @@ export class SignalKClient {
       `${this.protocol}://${this.hostname}:${this.port}/signalk/${this._version}/auth/logout`;
 
     debug(`put ${url}`);
-    const headers = new Headers({ "Content-Type": "application/json" });
+    const headers = new Headers({ 'Content-Type': 'application/json' });
     if (this._token) {
-      headers.append("Authorization", `JWT ${this._token}`);
+      headers.append('Authorization', `JWT ${this._token}`);
     }
 
     const options = {
-      method: "PUT",
+      method: 'PUT',
       headers: headers,
       body: null,
     };
@@ -620,15 +620,15 @@ export class SignalKClient {
    */
   async isLoggedIn(): Promise<boolean> {
     const response = await this.getLoginStatus();
-    return response.status === "loggedIn" ? true : false;
+    return response.status === 'loggedIn' ? true : false;
   }
 
   /** Fetch Signal K login status from server */
   getLoginStatus(): Promise<{ [key: string]: unknown }> {
     let url = `/skServer/loginStatus`;
-    if (this.server && this.server.info.id === "signalk-server-node") {
-      const ver = this.server.info["version"].split(".");
-      url = ver[0] === "1" && parseInt(ver[1]) < 36 //use legacy link for older versions
+    if (this.server && this.server.info.id === 'signalk-server-node') {
+      const ver = this.server.info['version'].split('.');
+      url = ver[0] === '1' && parseInt(ver[1]) < 36 //use legacy link for older versions
         ? `/loginstatus`
         : url;
     }
@@ -641,14 +641,14 @@ export class SignalKClient {
    */
   snapshot(context: string, time: string): Promise<{ [key: string]: unknown }> {
     if (!time) {
-      throw new Error("Error: No time value supplied!");
+      throw new Error('Error: No time value supplied!');
     }
-    time = time.slice(0, time.indexOf(".")) + "Z";
+    time = time.slice(0, time.indexOf('.')) + 'Z';
     let url = this.resolveHttpEndpoint();
     if (!url) {
-      throw new Error("Error: Unable to resolve URL!");
+      throw new Error('Error: Unable to resolve URL!');
     }
-    url = `${url.replace("api", "snapshot")}${
+    url = `${url.replace('api', 'snapshot')}${
       Path.contextToPath(
         context,
       )
@@ -671,7 +671,7 @@ export class SignalKClient {
     id?: string,
   ): Promise<{ [key: string]: unknown }> {
     if (!name) {
-      throw new Error("Error: Name not supplied!");
+      throw new Error('Error: Name not supplied!');
     }
 
     if (!id && !this.clientId) {
@@ -696,7 +696,7 @@ export class SignalKClient {
    */
   async checkAccessRequest(href: string): Promise<{ [key: string]: unknown }> {
     if (!href) {
-      throw new Error("Error: href not supplied!");
+      throw new Error('Error: href not supplied!');
     }
     return await this.get(href);
   }
@@ -710,12 +710,12 @@ export class SignalKClient {
   /** Target application id.
    * @private
    */
-  private _appId = "";
+  private _appId = '';
 
   /** Target application version.
    * @private
    */
-  private _appVersion = "";
+  private _appVersion = '';
 
   /** Return endpoint for target app. */
   private resolveAppDataEndpoint(
@@ -723,9 +723,9 @@ export class SignalKClient {
     appId: string,
   ): string {
     if (!context || !appId) {
-      return "";
+      return '';
     }
-    const url = this.resolveHttpEndpoint().replace("api", "applicationData");
+    const url = this.resolveHttpEndpoint().replace('api', 'applicationData');
     return `${url}${context}/${appId}/`;
   }
 
@@ -762,12 +762,12 @@ export class SignalKClient {
    * @param version Version of data
    */
   appDataKeys(
-    path = "",
+    path = '',
     context: APPDATA_CONTEXT = APPDATA_CONTEXT.USER,
     appId: string = this._appId,
     version: string = this._appVersion,
   ): Promise<{ [key: string]: unknown }> {
-    path = path.length != 0 && path[0] === "/" ? path.slice(1) : path;
+    path = path.length != 0 && path[0] === '/' ? path.slice(1) : path;
     let url = this.resolveAppDataEndpoint(context, appId);
     url += `${version}/${path}?keys=true`;
     return this.get(url);
@@ -780,12 +780,12 @@ export class SignalKClient {
    * @param version Version of data
    */
   appDataGet(
-    path = "",
+    path = '',
     context: APPDATA_CONTEXT = APPDATA_CONTEXT.USER,
     appId: string = this._appId,
     version: string = this._appVersion,
   ): Promise<{ [key: string]: unknown }> {
-    path = path.length != 0 && path[0] === "/" ? path.slice(1) : path;
+    path = path.length != 0 && path[0] === '/' ? path.slice(1) : path;
     let url = this.resolveAppDataEndpoint(context, appId);
     url += `${version}/${path}`;
     return this.get(url);
@@ -805,14 +805,14 @@ export class SignalKClient {
     version: string = this._appVersion,
   ): Promise<Response> {
     if (!path) {
-      throw new Error("Error: Invalid path!");
+      throw new Error('Error: Invalid path!');
     }
-    if (path[0] === "/") {
+    if (path[0] === '/') {
       path = path.slice(1);
     }
     const ep = this.resolveAppDataEndpoint(context, appId);
     if (!ep) {
-      throw new Error("Error: Invalid path!");
+      throw new Error('Error: Invalid path!');
     }
     return this.post(
       `${ep}${version}/${Path.dotToSlash(path)}`,
@@ -834,7 +834,7 @@ export class SignalKClient {
   ): Promise<Response> {
     const ep = this.resolveAppDataEndpoint(context, appId);
     if (!ep || !version) {
-      throw new Error("Error: Invalid path or version!");
+      throw new Error('Error: Invalid path or version!');
     }
     return this.post(`${ep}${version}`, value);
   }
diff --git a/signalk-client/stream-api.ts b/signalk-client/stream-api.ts
index 49d61e6..8faef9f 100644
--- a/signalk-client/stream-api.ts
+++ b/signalk-client/stream-api.ts
@@ -1,6 +1,6 @@
-import { EventEmitter } from "https://deno.land/x/eventemitter@1.2.1/mod.ts";
-import { Alarm, AlarmType, Message } from "./utils.ts";
-import { debug } from "./mod.ts";
+import { EventEmitter } from 'https://deno.land/x/eventemitter@1.2.1/mod.ts';
+import { Alarm, AlarmType, Message } from './utils.ts';
+import { debug } from './mod.ts';
 
 /** Signal K Stream operations */
 export class SignalKStream {
@@ -10,7 +10,7 @@ export class SignalKStream {
   /** id of vessel to filter delta messages
    * @private
    */
-  private _filter = "";
+  private _filter = '';
 
   /** websocket connection timeout
    * @private
@@ -20,7 +20,7 @@ export class SignalKStream {
   /** Authentication token
    * @private
    */
-  private _token = "";
+  private _token = '';
 
   /** Playback mode flag
    * @private */
@@ -34,20 +34,20 @@ export class SignalKStream {
   /** Client Id for approved device
    * @private
    */
-  private _clientId: any = "";
+  private _clientId: any = '';
 
   // **************** ATTRIBUTES ***************************
 
   /** API version to use */
   public version = 1;
   /** Connection endpoint */
-  public endpoint = "";
+  public endpoint = '';
   /** self identifier value */
-  public selfId = "";
+  public selfId = '';
 
-  /** Set source label for use in messages 
+  /** Set source label for use in messages
    * @param val label value
-  */
+   */
   set source(val: string) {
     if (!this._source) {
       this._source = {};
@@ -55,9 +55,9 @@ export class SignalKStream {
     this._source['label'] = val;
   }
 
-  /** Set auth token value 
+  /** Set auth token value
    * @param val token value
-  */
+   */
   set authToken(val: string) {
     this._token = val;
   }
@@ -93,8 +93,8 @@ export class SignalKStream {
 
   /** Apply a filter for stream messages. Set filter = null to remove message filtering */
   set filter(id: string) {
-    if (id && id.indexOf("self") != -1) {
-      this._filter = this.selfId ? this.selfId : "";
+    if (id && id.indexOf('self') != -1) {
+      this._filter = this.selfId ? this.selfId : '';
     } else {
       this._filter = id;
     }
@@ -109,10 +109,10 @@ export class SignalKStream {
 
   /** Stream events */
   public events: EventEmitter<{
-    "connect"(ev: Event): any;
-    "close"(ev: Event): any;
-    "error"(ev: Event): any;
-    "message"(ev: MessageEvent): any;
+    'connect'(ev: Event): any;
+    'close'(ev: Event): any;
+    'error'(ev: Event): any;
+    'message'(ev: MessageEvent): any;
   }>;
 
   constructor() {
@@ -137,12 +137,12 @@ export class SignalKStream {
     if (!url) {
       return;
     }
-    let q = url.indexOf("?") === -1 ? "?" : "&";
+    let q = url.indexOf('?') === -1 ? '?' : '&';
     if (subscribe) {
       url += `${q}subscribe=${subscribe}`;
     }
     if (this._token || token) {
-      url += `${subscribe ? "&" : "?"}token=${this._token || token}`;
+      url += `${subscribe ? '&' : '?'}token=${this._token || token}`;
     }
 
     this.close();
@@ -160,13 +160,13 @@ export class SignalKStream {
     }, this._wsTimeout);
 
     this.ws.onopen = (e: Event) => {
-      this.events.emit("connect", e);
+      this.events.emit('connect', e);
     };
     this.ws.onclose = (e: Event) => {
-      this.events.emit("close", e);
+      this.events.emit('close', e);
     };
     this.ws.onerror = (e: Event) => {
-      this.events.emit("error", e);
+      this.events.emit('error', e);
     };
     this.ws.onmessage = (e: MessageEvent) => {
       this.parseOnMessage(e);
@@ -178,7 +178,7 @@ export class SignalKStream {
    */
   private parseOnMessage(e: MessageEvent) {
     let data: any;
-    if (typeof e.data === "string") {
+    if (typeof e.data === 'string') {
       try {
         data = JSON.parse(e.data);
       } catch {
@@ -187,21 +187,21 @@ export class SignalKStream {
     }
     if (this.isHello(data)) {
       this.selfId = data.self;
-      this._playbackMode = typeof data.startTime != "undefined" ? true : false;
-      this.events.emit("message", data);
+      this._playbackMode = typeof data.startTime != 'undefined' ? true : false;
+      this.events.emit('message', data);
     } else if (this.isResponse(data)) {
-      if (typeof data.login !== "undefined") {
-        if (typeof data.login.token !== "undefined") {
+      if (typeof data.login !== 'undefined') {
+        if (typeof data.login.token !== 'undefined') {
           this._token = data.login.token;
         }
       }
-      this.events.emit("message", data);
+      this.events.emit('message', data);
     } else if (this._filter && this.isDelta(data)) {
       if (data.context === this._filter) {
-        this.events.emit("message", data);
+        this.events.emit('message', data);
       }
     } else {
-      this.events.emit("message", data);
+      this.events.emit('message', data);
     }
   }
 
@@ -210,24 +210,24 @@ export class SignalKStream {
    * @returns String containing requestId
    */
   sendRequest(value: any): string {
-    if (typeof value !== "object") {
-      return "";
+    if (typeof value !== 'object') {
+      return '';
     }
     const msg: any = Message.request();
-    debug("requestId: ", msg.requestId);
-    debug("_token: ", this._token);
-    if (typeof value.login === "undefined" && this._token) {
-      msg["token"] = this._token;
+    debug('requestId: ', msg.requestId);
+    debug('_token: ', this._token);
+    if (typeof value.login === 'undefined' && this._token) {
+      msg['token'] = this._token;
     }
-    debug("_clientId: ", this._clientId);
+    debug('_clientId: ', this._clientId);
     if (this._clientId) {
-      msg["clientId"] = this._clientId;
+      msg['clientId'] = this._clientId;
     }
     const keys = Object.keys(value);
     keys.forEach((k) => {
       msg[k] = value[k];
     });
-    debug("msg: ", msg);
+    debug('msg: ', msg);
     this.send(msg);
     return msg.requestId;
   }
@@ -240,7 +240,7 @@ export class SignalKStream {
    */
   put(context: string, path: string, value: any): string {
     const msg = {
-      context: context === "self" ? "vessels.self" : context,
+      context: context === 'self' ? 'vessels.self' : context,
       put: { path: path, value: value },
     };
     return this.sendRequest(msg);
@@ -263,7 +263,7 @@ export class SignalKStream {
    */
   send(data: any) {
     if (this.ws) {
-      if (typeof data === "object") {
+      if (typeof data === 'object') {
         data = JSON.stringify(data);
       }
       debug(`sending -> `, data);
@@ -283,25 +283,25 @@ export class SignalKStream {
   sendUpdate(context: string, path: Array<any>): void;
   sendUpdate(context: string, path: string, value: any): void;
   sendUpdate(
-    context = "self",
+    context = 'self',
     path: string | Array<any>,
     value?: any,
   ) {
     const val: any = Message.updates();
     if (this._token) {
-      val["token"] = this._token;
+      val['token'] = this._token;
     }
-    debug("_clientId: ", this._clientId);
+    debug('_clientId: ', this._clientId);
     if (this._clientId) {
-      val["clientId"] = this._clientId;
+      val['clientId'] = this._clientId;
     }
-    val.context = context === "self" ? "vessels.self" : context;
+    val.context = context === 'self' ? 'vessels.self' : context;
 
     let uValues = [];
-    if (typeof path === "string") {
+    if (typeof path === 'string') {
       uValues.push({ path: path, value: value });
     }
-    if (typeof path === "object" && Array.isArray(path)) {
+    if (typeof path === 'object' && Array.isArray(path)) {
       uValues = path;
     }
     const u: any = {
@@ -309,7 +309,7 @@ export class SignalKStream {
       values: uValues,
     };
     if (this._source) {
-      u["source"] = this._source;
+      u['source'] = this._source;
     }
     val.updates.push(u);
     this.send(val);
@@ -327,45 +327,45 @@ export class SignalKStream {
   subscribe(context: string, path: Array<any>): void;
   subscribe(context: string, path: string, options?: any): void;
   subscribe(
-    context = "*",
-    path: string | Array<any> = "*",
+    context = '*',
+    path: string | Array<any> = '*',
     options?: any,
   ) {
     const val: any = Message.subscribe();
     if (this._token) {
-      val["token"] = this._token;
+      val['token'] = this._token;
     }
-    val.context = context === "self" ? "vessels.self" : context;
+    val.context = context === 'self' ? 'vessels.self' : context;
     if (this._token) {
-      val["token"] = this._token;
+      val['token'] = this._token;
     }
 
-    if (typeof path === "object" && Array.isArray(path)) {
+    if (typeof path === 'object' && Array.isArray(path)) {
       val.subscribe = path;
     }
-    if (typeof path === "string") {
+    if (typeof path === 'string') {
       const sValue: any = {};
-      sValue["path"] = path;
-      if (options && typeof options === "object") {
-        if (options["period"]) {
-          sValue["period"] = options["period"];
+      sValue['path'] = path;
+      if (options && typeof options === 'object') {
+        if (options['period']) {
+          sValue['period'] = options['period'];
         }
-        if (options["minPeriod"]) {
-          sValue["minPeriod"] = options["period"];
+        if (options['minPeriod']) {
+          sValue['minPeriod'] = options['period'];
         }
         if (
-          options["format"] &&
-          (options["format"] === "delta" || options["format"] === "full")
+          options['format'] &&
+          (options['format'] === 'delta' || options['format'] === 'full')
         ) {
-          sValue["format"] = options["format"];
+          sValue['format'] = options['format'];
         }
         if (
-          options["policy"] &&
-          (options["policy"] === "instant" ||
-            options["policy"] === "ideal" ||
-            options["policy"] === "fixed")
+          options['policy'] &&
+          (options['policy'] === 'instant' ||
+            options['policy'] === 'ideal' ||
+            options['policy'] === 'fixed')
         ) {
-          sValue["policy"] = options["policy"];
+          sValue['policy'] = options['policy'];
         }
       }
       val.subscribe.push(sValue);
@@ -377,26 +377,55 @@ export class SignalKStream {
    * @param context Signal K context
    * @param path Signal K path value
    */
-  unsubscribe(context = "*", path = "*") {
+  unsubscribe(context = '*', path = '*') {
     const val: any = Message.unsubscribe();
     if (this._token) {
-      val["token"] = this._token;
+      val['token'] = this._token;
     }
-    val.context = context === "self" ? "vessels.self" : context;
+    val.context = context === 'self' ? 'vessels.self' : context;
     if (this._token) {
-      val["token"] = this._token;
+      val['token'] = this._token;
     }
 
-    if (typeof path === "object" && Array.isArray(path)) {
+    if (typeof path === 'object' && Array.isArray(path)) {
       val.unsubscribe = path;
     }
-    if (typeof path === "string") {
+    if (typeof path === 'string') {
       val.unsubscribe.push({ path: path });
     }
     this.send(val);
   }
 
- 
+  /** Access request
+   * @param name Name of sensor / process requesting access
+   * @param id Client id
+   * @returns requestId
+   */
+  accessRequest(
+    name: string,
+    id?: string,
+  ): string {
+    if (!name) {
+      throw new Error('Error: Name not supplied!');
+    }
+
+    if (!id && !this.clientId) {
+      this.clientId = crypto.randomUUID();
+    } else if (!this.clientId) {
+      this.clientId = id;
+    }
+
+    const req = {
+      requestId: crypto.randomUUID(),
+      accessRequest: {
+        clientId: this.clientId,
+        description: name,
+        permissions: 'admin',
+      },
+    };
+    this.send(req);
+    return req.requestId;
+  }
 
   /** Raise alarm
    * @param context Signal K context
@@ -410,10 +439,10 @@ export class SignalKStream {
    */
   raiseAlarm(context: string, name: string, alarm: Alarm): void;
   raiseAlarm(context: string, type: AlarmType, alarm: Alarm): void;
-  raiseAlarm(context = "*", alarmId: string | AlarmType, alarm: Alarm) {
+  raiseAlarm(context = '*', alarmId: string | AlarmType, alarm: Alarm) {
     let path: string;
-    if (typeof alarmId === "string") {
-      path = alarmId.indexOf("notifications.") === -1
+    if (typeof alarmId === 'string') {
+      path = alarmId.indexOf('notifications.') === -1
         ? `notifications.${alarmId}`
         : alarmId;
     } else {
@@ -426,8 +455,8 @@ export class SignalKStream {
    * @param context Signal K context
    * @param name alarm name
    */
-  clearAlarm(context = "*", name: string) {
-    const path = name.indexOf("notifications.") === -1
+  clearAlarm(context = '*', name: string) {
+    const path = name.indexOf('notifications.') === -1
       ? `notifications.${name}`
       : name;
     this.put(context, path, null);
@@ -445,20 +474,20 @@ export class SignalKStream {
    * @param msg Received stream message
    */
   isDelta(msg: any): boolean {
-    return typeof msg.context != "undefined";
+    return typeof msg.context != 'undefined';
   }
 
   /** Tests if message is a Hello message
    * @param msg Received stream message
    */
   isHello(msg: any): boolean {
-    return typeof msg.version != "undefined" && typeof msg.self != "undefined";
+    return typeof msg.version != 'undefined' && typeof msg.self != 'undefined';
   }
 
   /** Tests if message is a request Response message
    * @param msg Received stream message
    */
   isResponse(msg: any): boolean {
-    return typeof msg.requestId != "undefined";
+    return typeof msg.requestId != 'undefined';
   }
 }
diff --git a/signalk-client/utils.ts b/signalk-client/utils.ts
index c23389c..3f933d9 100644
--- a/signalk-client/utils.ts
+++ b/signalk-client/utils.ts
@@ -2,8 +2,8 @@
 export interface Subscription {
   path: string;
   period?: number;
-  format?: "delta" | "full";
-  policy?: "instant" | "ideal" | "fixed";
+  format?: 'delta' | 'full';
+  policy?: 'instant' | 'ideal' | 'fixed';
   minPeriod?: number;
 }
 
@@ -14,11 +14,11 @@ export class Path {
    * @returns Path in slash notation e.g. navigation/position
    */
   static dotToSlash(path: string): string {
-    const p = path.split("?");
-    if (p[0].indexOf(".") != -1) {
-      p[0] = p[0].split(".").join("/");
+    const p = path.split('?');
+    if (p[0].indexOf('.') != -1) {
+      p[0] = p[0].split('.').join('/');
     }
-    return p.join("?");
+    return p.join('?');
   }
 
   /** parse context to valid Signal K path
@@ -26,8 +26,8 @@ export class Path {
    * @returns context in slash notation
    */
   static contextToPath(context: string): string {
-    const res = context === "self" ? "vessels.self" : context;
-    return res.split(".").join("/");
+    const res = context === 'self' ? 'vessels.self' : context;
+    return res.split('.').join('/');
   }
 }
 
@@ -93,7 +93,7 @@ export class Alarm {
   /** Alarm Message text
    * @private
    */
-  private _message = "";
+  private _message = '';
 
   /**
    * @param message Alarm message text
@@ -107,8 +107,8 @@ export class Alarm {
     visual?: boolean,
     sound?: boolean,
   ) {
-    this._message = typeof message !== "undefined" ? message : "";
-    this._state = typeof state !== "undefined" ? state : AlarmState.alarm;
+    this._message = typeof message !== 'undefined' ? message : '';
+    this._state = typeof state !== 'undefined' ? state : AlarmState.alarm;
     if (visual) {
       this._method.push(AlarmMethod.visual);
     }
@@ -129,29 +129,29 @@ export class Alarm {
 
 /** AlarmState values */
 export enum AlarmState {
-  normal = "normal",
-  alert = "alert",
-  warn = "warn",
-  alarm = "alarm",
-  emergency = "emergency",
+  normal = 'normal',
+  alert = 'alert',
+  warn = 'warn',
+  alarm = 'alarm',
+  emergency = 'emergency',
 }
 
 /** AlarmMethod values */
 export enum AlarmMethod {
-  visual = "visual",
-  sound = "sound",
+  visual = 'visual',
+  sound = 'sound',
 }
 
 /** AlarmType values */
 export enum AlarmType {
-  mob = "notifications.mob",
-  fire = "notifications.fire",
-  sinking = "notifications.sinking",
-  flooding = "notifications.flooding",
-  collision = "notifications.collision",
-  grounding = "notifications.grounding",
-  listing = "notifications.listing",
-  adrift = "notifications.adrift",
-  piracy = "notifications.piracy",
-  abandon = "notifications.abandon",
+  mob = 'notifications.mob',
+  fire = 'notifications.fire',
+  sinking = 'notifications.sinking',
+  flooding = 'notifications.flooding',
+  collision = 'notifications.collision',
+  grounding = 'notifications.grounding',
+  listing = 'notifications.listing',
+  adrift = 'notifications.adrift',
+  piracy = 'notifications.piracy',
+  abandon = 'notifications.abandon',
 }