diff --git a/build/output/browser/postal.js b/build/output/browser/postal.js
index dad71b1..c9634de 100644
--- a/build/output/browser/postal.js
+++ b/build/output/browser/postal.js
@@ -193,9 +193,8 @@ var localBus = {
 
     wireTaps: [],
 
-    publish: function(envelope) {
-        envelope.exchange = envelope.exchange || DEFAULT_EXCHANGE;
-        envelope.timeStamp = new Date();
+    publish: function(config) {
+        var envelope = _.extend(defaultConfiguration, { timeStamp: new Date() }, config);
         _.each(this.wireTaps,function(tap) {
             tap({
                     exchange:   envelope.exchange,
diff --git a/build/output/nodejs/postal.js b/build/output/nodejs/postal.js
index 7e6dc0e..0f2d8ea 100644
--- a/build/output/nodejs/postal.js
+++ b/build/output/nodejs/postal.js
@@ -191,9 +191,8 @@ var localBus = {
 
     wireTaps: [],
 
-    publish: function(envelope) {
-        envelope.exchange = envelope.exchange || DEFAULT_EXCHANGE;
-        envelope.timeStamp = new Date();
+    publish: function(config) {
+        var envelope = _.extend(defaultConfiguration, { timeStamp: new Date() }, config);
         _.each(this.wireTaps,function(tap) {
             tap({
                     exchange:   envelope.exchange,
diff --git a/src/Bus.js b/src/Bus.js
index a2c674e..2a5368b 100644
--- a/src/Bus.js
+++ b/src/Bus.js
@@ -21,9 +21,8 @@ var localBus = {
 
     wireTaps: [],
 
-    publish: function(envelope) {
-        envelope.exchange = envelope.exchange || DEFAULT_EXCHANGE;
-        envelope.timeStamp = new Date();
+    publish: function(config) {
+        var envelope = _.extend(defaultConfiguration, { timeStamp: new Date() }, config);
         _.each(this.wireTaps,function(tap) {
             tap({
                     exchange:   envelope.exchange,