diff --git a/src/css/resting.css b/src/css/resting.css
index 8f71bf6..b09ea4a 100644
--- a/src/css/resting.css
+++ b/src/css/resting.css
@@ -36,10 +36,17 @@ body {
  z-index: 100;
 }
 
+.context-dialog {
+ position: absolute;
+ top: 100px;
+ width: 700px;
+ z-index: 100;
+}
+
 .bookmark {
  display: block;
  padding: 10px 15px;
- cursor: pointer; 
+ cursor: pointer;
 }
 
 .folder {
@@ -54,7 +61,7 @@ a.bookmark, a.folder {
 }
 
 a.folder:hover, a.bookmark:hover, .folder .panel-heading:hover {
- background-color: #337ab7; 
+ background-color: #337ab7;
  color: #fff;
 }
 
@@ -82,3 +89,39 @@ label.disabled {
   color: gray;
 }
 
+.dropdown-submenu{ position: relative; }
+
+.dropdown-submenu>.dropdown-menu{
+  top:0;
+  left:100%;
+  margin-top:-6px;
+  margin-left:-1px;
+  -webkit-border-radius:0 6px 6px 6px;
+  -moz-border-radius:0 6px 6px 6px;
+  border-radius:0 6px 6px 6px;
+}
+
+.dropdown-submenu>a:after{
+  display:block;
+  content:" ";
+  float:right;
+  width:0;
+  height:0;
+  border-color:transparent;
+  border-style:solid;
+  border-width:5px 0 5px 5px;
+  border-left-color:#cccccc;
+  margin-top:5px;margin-right:-10px;
+}
+.dropdown-submenu:hover>a:after{
+  border-left-color:#555;
+}
+.dropdown-submenu.pull-left{ float: none; }
+.dropdown-submenu.pull-left>.dropdown-menu{
+  left: -100%;
+  margin-left: 10px;
+  -webkit-border-radius: 6px 0 6px 6px;
+  -moz-border-radius: 6px 0 6px 6px;
+  border-radius: 6px 0 6px 6px;
+}
+
diff --git a/src/index.html b/src/index.html
index bbf3308..8dc203a 100644
--- a/src/index.html
+++ b/src/index.html
@@ -39,6 +39,15 @@
         </div>
         <div class="collapse navbar-collapse">
             <ul class="nav navbar-nav">
+              <li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown"><h4>Settings <b class="caret"></b></h4></a>
+                  <ul class="dropdown-menu">
+                      <li class="dropdown dropdown-submenu"><a href="#" class="dropdown-toggle" data-toggle="dropdown">Contexts</a>
+                        <ul class="dropdown-menu">
+                          <li><a href="#" data-bind="click: contextDialog">default</a></li>
+                        </ul>
+                      </li>
+                  </ul>
+              </li>
               <li><a href="#" data-bind="click: aboutDialog"><h4>About</h4></a></li>
               <li><a href="#" data-bind="click: creditsDialog"><h4>Credits</h4></a></li>
             </ul>
@@ -198,7 +207,7 @@ <h4 class="panel-title"><a href="#" data-bind="click: responseHeadersPanel">Head
       About Resting<span style="cursor: pointer;" class="glyphicon glyphicon-remove pull-right" data-bind="click: dismissAboutDialog"></span>
     </div>
     <div class="panel-body">
-      <h4>Resting v0.7.3</h4>
+      <h4>Resting v0.8.0</h4>
       <a target="_blank" href="https://github.com/mirkoperillo/resting">Project Website</a> --
       <a target="_blank" href="https://github.com/mirkoperillo/resting/issues">Issue tracker</a>
     </div>
@@ -213,6 +222,28 @@ <h4>Resting v0.7.3</h4>
     </div>
   </div>
 
+   <div id="context-dialog" class="panel panel-primary context-dialog" data-bind="visible: showContextDialog">
+    <div class="panel-heading">
+      Context <span data-bind="text: contexts.name"></span><span style="cursor: pointer;" class="glyphicon glyphicon-remove pull-right" data-bind="click: dismissContextDialog"></span>
+    </div>
+    <div class="panel-body">
+      <p>
+        Use variables as <strong>{var_name}</strong> in
+        <ul>
+          <li>the request URL</li>
+          <li>value of header</li>
+          <li>part of the body</li>
+          <li>value of querystring</li>
+          <li>as username and password in BASIC authentication</li>
+        </ul>
+      </p>
+      <entry-list params="entryList : contexts.variables"></entry-list>
+    </div>
+     <div class="panel-footer">
+      <button class="btn btn-default" data-bind="click: saveContext">Save</button><button class="btn btn-default" data-bind="click: dismissContextDialog">Cancel</button>
+    </div>
+  </div>
+
     <script data-main="js/app" src="js/require.js"></script>
 
   </div>
diff --git a/src/js/app.js b/src/js/app.js
index 4a50134..516b904 100644
--- a/src/js/app.js
+++ b/src/js/app.js
@@ -12,6 +12,13 @@ requirejs.config({
 
 requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','app/request','app/bookmark','bootstrap'], function($,storage,ko,ksb,hjls,request,makeBookmarkProvider, bootstrap) {
 
+  function ContextVm(createDefault) {
+    const self = this;
+    this.name = ko.observable(createDefault ? 'default' : '');
+    this.variables = ko.observableArray();
+    this.isDefault = createDefault;
+  };
+
   function RequestVm(request = {}) {
     const self = this;
     this.method = ko.observable('');
@@ -49,6 +56,8 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
 
   function AppViewModel() {
     const Resting = {
+      contexts : new ContextVm(true),
+
       bookmarkSelected : new BookmarkSelectedVm(),
       requestSelected : new RequestVm(),
       responseContent : {},
@@ -92,13 +101,14 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
       showBookmarkDeleteDialog: ko.observable(false),
       showAboutDialog: ko.observable(false),
       showCreditsDialog: ko.observable(false),
+      showContextDialog: ko.observable(false),
     };
 
     const bookmarkProvider = makeBookmarkProvider(storage);
 
-    const convertToFormData = (data = []) =>
+    const convertToFormData = (data = [], context = {}) =>
       data.filter(param => param.enabled()).reduce((acc, record) => {
-        acc[record.name()] = record.value();
+        acc[record.name()] = _applyContext(record.value(),context);
         return acc;
       }, {});
 
@@ -114,6 +124,10 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
       Resting.showCreditsDialog(true);
     };
 
+     const contextDialog = () => {
+      Resting.showContextDialog(true);
+    };
+
     const dismissCreditsDialog = () => {
       Resting.showCreditsDialog(false);
     };
@@ -122,8 +136,12 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
       Resting.showAboutDialog(false);
     };
 
-    const convertToUrlEncoded = (data = []) =>
-      data.filter(param => param.enabled()).map( param => `${param.name()}=${param.value()}`).join('&');
+    const dismissContextDialog = () => {
+      Resting.showContextDialog(false);
+    };
+
+    const convertToUrlEncoded = (data = [], context) =>
+      data.filter(param => param.enabled()).map( param => `${param.name()}=${_applyContext(param.value(),context)}`).join('&');
 
     const updateBody = (bodyType, body) => {
       clearRequestBody();
@@ -197,17 +215,20 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
       }
     };
 
-    const dataToSend = () => {
+    const dataToSend = (context) => {
       if (Resting.bodyType() === 'form-data') {
-        return convertToFormData(Resting.formDataParams());
+        return convertToFormData(Resting.formDataParams(),context);
       } else if (Resting.bodyType() === 'x-www-form-urlencoded') {
-        return convertToUrlEncoded(Resting.formEncodedParams());
+        return convertToUrlEncoded(Resting.formEncodedParams(), context);
       } else if (Resting.bodyType() === 'raw') {
-        return Resting.rawBody().trim();
+        return _applyContext(Resting.rawBody().trim(),context);
       }
     };
 
-    const _authentication = () => ({type: Resting.authenticationType(), username: Resting.username(), password: Resting.password()});
+    const _applyContextToArray = (a = [], context = {}) => {
+      return
+    };
+    const _authentication = (context = {}) => ({type: Resting.authenticationType(), username: _applyContext(Resting.username(),context), password: _applyContext(Resting.password(),context)});
 
     const body = (bodyType) => {
       if (bodyType === 'form-data') {
@@ -346,9 +367,9 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
       }
     };
 
-    const convertToHeaderObj = headersList =>
+    const convertToHeaderObj = (headersList = [], context = {}) =>
       headersList.filter(header => header.enabled()).reduce((acc, header) => {
-        acc[header.name()] = header.value();
+        acc[header.name()] = _applyContext(header.value(),context);
         return acc;
       }, {});
 
@@ -367,16 +388,44 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
       }
     };
 
-    const _convertToQueryString = (params = []) => {
-      return params.filter(param => param.enabled()).map( param => ({name: param.name(), value: param.value()}));
+    const _convertToQueryString = (params = [], context = {}) => {
+      return params.filter(param => param.enabled()).map( param => ({name: param.name(), value: _applyContext(param.value(), context)}));
     };
 
     const send = () => {
+      const mapping = _mapContext();
       if(Resting.requestSelected.url() && Resting.requestSelected.url().trim().length > 0) {
         clearResponse();
-        request.execute(Resting.requestSelected.method(),Resting.requestSelected.url(),convertToHeaderObj(Resting.requestHeaders()), _convertToQueryString(Resting.querystring()), Resting.bodyType(),Resting.dataToSend(),
-        _authentication(),displayResponse);
+        const url = _applyContext(Resting.requestSelected.url(),mapping);
+        request.execute(Resting.requestSelected.method(),url,convertToHeaderObj(Resting.requestHeaders(), mapping), _convertToQueryString(Resting.querystring(), mapping), Resting.bodyType(),Resting.dataToSend(mapping),
+        _authentication(mapping),displayResponse);
+      }
+    };
+
+    const _mapContext = () => {
+      const mapping = {};
+      Resting.contexts.variables().filter(v => v.enabled()).forEach( v => mapping[v.name()] = v.value());
+      return mapping;
+    };
+
+    const _applyContext = (value = '',context = {}) => {
+      const tokens = _tokenize(value);
+      let computed = value.slice(0);
+      if(tokens) {
+        tokens.forEach(t => {
+          const contextVar = t.substring(1,t.length-1);
+          if(context[contextVar]) {
+            computed = computed.replace(t, context[contextVar]);
+          }
+        });
       }
+      return computed;
+    };
+
+    const _tokenize = (v = '') => {
+      const varRegexp = /\{\w+\}/g;
+      const tokens = v.match(varRegexp);
+      return tokens;
     };
 
     const loadBookmarkInView = (bookmark = {}) => {
@@ -471,6 +520,19 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
       }
     };
 
+    const saveContext = () => {
+      storage.saveContext({name : Resting.contexts.name(), variables : _extractModelFromVM(Resting.contexts.variables()) });
+      dismissContextDialog();
+    };
+
+    const loadContexts = () => {
+      // load contexts
+      storage.loadContexts( ctx => {
+        Resting.contexts.variables(_convertToEntryItemVM(ctx.variables));
+      });
+    };
+
+
     Resting.parseRequest = parseRequest;
     Resting.dataToSend = dataToSend;
     Resting.send = send;
@@ -491,8 +553,11 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
     Resting.reset = reset;
     Resting.aboutDialog = aboutDialog;
     Resting.creditsDialog = creditsDialog;
+    Resting.contextDialog = contextDialog;
     Resting.dismissCreditsDialog = dismissCreditsDialog;
     Resting.dismissAboutDialog = dismissAboutDialog;
+    Resting.dismissContextDialog = dismissContextDialog;
+    Resting.saveContext = saveContext;
 
     // FIXME: not good to expose this internal function
     Resting._saveBookmark = _saveBookmark;
@@ -500,6 +565,8 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
     Resting.loadBookmarkInView = loadBookmarkInView;
     Resting.isBookmarkLoaded = isBookmarkLoaded;
     Resting.bookmarkScreenName = bookmarkScreenName;
+    Resting.loadContexts = loadContexts;
+
     return Resting;
   }
 
@@ -531,6 +598,7 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
     });
 
 
+
    // Show all options, more restricted setup than the Knockout regular binding.
    var options = {
      attribute: "data-bind",        // default "data-sbind"
@@ -541,6 +609,17 @@ requirejs(['jquery','app/storage','knockout','knockout-secure-binding','hjls','a
 
    ko.bindingProvider.instance = new ksb(options);
 
-   ko.applyBindings(new AppViewModel());
+   const appVM = new AppViewModel();
+   ko.applyBindings(appVM);
+
+  $('ul.dropdown-menu [data-toggle=dropdown]').on('click', function(event) {
+    event.preventDefault();
+    event.stopPropagation();
+    $(this).parent().siblings().removeClass('open');
+    $(this).parent().toggleClass('open');
+  });
+
+  appVM.loadContexts();
+
   });
 });
diff --git a/src/js/app/storage.js b/src/js/app/storage.js
index 1b5ee94..4037762 100644
--- a/src/js/app/storage.js
+++ b/src/js/app/storage.js
@@ -4,11 +4,16 @@ define(['localforage'],function(localforage){
       name: 'resting',
       storeName: 'bookmarks',
     });
-    
+
+    const _contextsStore = localforage.createInstance({
+      name: 'resting',
+      storeName: 'contexts',
+    });
+
     const deleteById = (id, callback) => {
       localforage.removeItem(id, callback);
     };
-    
+
     const save = (bookmark) => {
       if(!bookmark.id) {
         return { result: 'KO', message: 'id must be set'};
@@ -16,22 +21,35 @@ define(['localforage'],function(localforage){
       localforage.setItem(bookmark.id, bookmark);
       return { result: 'OK', message: ''};
     };
-    
+
     const iterate = (callback, callbackResult) => {
       if(!callbackResult) {
-       localforage.iterate(function(value,key,iterationNumber) { 
+       localforage.iterate(function(value,key,iterationNumber) {
         callback(value);
        });
       } else {
-        localforage.iterate(function(value,key,iterationNumber) { 
+        localforage.iterate(function(value,key,iterationNumber) {
           callback(value);
        }, callbackResult);
       };
     };
-    
+
+    const saveContext = (context) => {
+      _contextsStore.setItem(context.name, context);
+      return { result: 'OK', message: ''};
+    };
+
+    const loadContexts = (callback) => {
+      _contextsStore.iterate(function(value,key,iterationNumber) {
+        callback(value);
+       });
+    };
+
     return {
       save : save,
       deleteById : deleteById,
       iterate : iterate,
+      saveContext,
+      loadContexts,
     };
 });
diff --git a/src/manifest.json b/src/manifest.json
index ebcdca2..658465c 100644
--- a/src/manifest.json
+++ b/src/manifest.json
@@ -2,7 +2,7 @@
   "description": "rest client focused on organization of the saved requests",
   "manifest_version": 2,
   "name": "Resting",
-  "version": "0.7.3",
+  "version": "0.8.0",
   "author" : "Mirko Perillo",
   "homepage_url": "https://github.com/mirkoperillo/resting",
   "icons": {