diff --git a/example_script.js b/example_script.js
index 5c762a7..5b8483e 100644
--- a/example_script.js
+++ b/example_script.js
@@ -34,7 +34,7 @@ var client = new plivo.Client('MAMDJMMTEZOWY0ZMQWM2', 'OTljNmVmOGVkNGZhNjJlOWIyM
 //   console.error(err);
 // });
 
-client.multiPartyCalls.addParticipant({'friendlyName' : 'TestMPC', 'from' : '+919090909090', 'to': 'sip:koushikqa119062465586783372208@phone-qa.voice.plivodev.com'}).then(function (response) {
+client.multiPartyCalls.addParticipant('agent', {"friendlyName" : "TestMPC", 'from' : '+919090909090', 'to': 'sip:koushikqa119062465586783372208@phone-qa.voice.plivodev.com'}).then(function (response) {
   console.log(response);
 }, function (err) {
   console.error(err);
diff --git a/lib/resources/multiPartyCall.js b/lib/resources/multiPartyCall.js
index 2eb71d8..9a049ef 100644
--- a/lib/resources/multiPartyCall.js
+++ b/lib/resources/multiPartyCall.js
@@ -45,9 +45,7 @@ export class MultiPartyCall extends PlivoResource{
       throw new MPCError('specify (from, to) when not adding an existing callUuid to multi party participant')
     }
 
-    if(params.role){
-      validParam('role', params.role.toLowerCase(), [String], true, ['agent', 'supervisor', 'customer'])
-    }
+    validParam('role', params.role.toLowerCase(), [String], true, ['agent', 'supervisor', 'customer'])
 
     if(params.from){
       validParam('from', params.from, [String], false)
@@ -295,7 +293,7 @@ export class MultiPartyCall extends PlivoResource{
     return super.delete()
   }
 
-  startRecording(params){
+    startRecording(params){
     if(params.fileFormat){
       validParam('fileFormat', params.fileFormat, [String], false, ['mp3', 'wav'])
     }
@@ -405,25 +403,6 @@ export class MultiPartyCallInterface extends PlivoResourceInterface{
     return identifier;
   }
 
-  /**
-   * List MultiPartyCalls
-   * @method
-   * @param {object} params
-   * @param {string} [params.subAccount]
-   * @param {string} [params.friendlyName]
-   * @param {string} [params.status]
-   * @param {number} [params.terminationCauseCode]
-   * @param {Date} [params.end_time__gt]
-   * @param {Date} [params.end_time__gte]
-   * @param {Date} [params.end_time__lt]
-   * @param {Date} [params.end_time__lte]
-   * @param {Date} [params.creation_time__gt]
-   * @param {Date} [params.creation_time__gte]
-   * @param {Date} [params.creation_time__lt]
-   * @param {Date} [params.creation_time__lte]
-   * @param {number} [params.limit]
-   * @param {number} [params.offset]
-   */
   list(params={}) {
     if(params.subAccount){
       validSubAccount(params.subAccount);
@@ -482,7 +461,7 @@ export class MultiPartyCallInterface extends PlivoResourceInterface{
     return new MultiPartyCall(this[clientKey], {id: mpcId[0] + mpcId[1]}).get();
   }
 
-  addParticipant(role, params = {}){
+  addParticipant( role = 'agent', params = {}){
     let errors = validate([
       {field: 'friendly_name', value: params.friendlyName, validators: ['isString']}
     ]);
@@ -495,10 +474,10 @@ export class MultiPartyCallInterface extends PlivoResourceInterface{
     if(params.friendlyName){
       validParam('friendlyName', params.friendlyName, [String], false)
     }
+    console.log(params.friendlyName);
     let mpcId = this.makeMpcId(params.uuid, params.friendlyName)
     delete params.uuid
     delete params.friendlyName
-    params.role = role
     return new MultiPartyCall(this[clientKey], {id: mpcId[0] + mpcId[1]}).addParticipant(params)
   }