diff --git a/API.js b/API.js
index 9e0cd8c35..45f280848 100644
--- a/API.js
+++ b/API.js
@@ -58,15 +58,15 @@ API.prototype._command = function(command, args, callback) {
     var argTypes = API.prototype[command].argTypes;
     API._coerceArgTypes(args, argTypes)
     if (!API._checkArgTypes(command, args))
-      throw new Error('Invalid arguments');
+      throw new Error('invalid arguments');
   }
 
-  if (typeof self[command] == 'function') {
+  if (typeof self["_cmd_" + command] == 'function') {
     var f = API.prototype[command];
     if (f.argTypes[f.argTypes.length-1][1] == 'function')
-      return self[command].apply(self, args.concat([callback]));
+      return self["_cmd_" + command].apply(self, args.concat([callback]));
     else
-      return callback(null, self[command].apply(self, args));
+      return callback(null, self["_cmd_" + command].apply(self, args));
   };
   
   return callback(new Error('invalid command'));
@@ -89,41 +89,48 @@ API._checkArgTypes = function(command, args) {
   return true;
 };
 
-API.prototype.echo = function echo(str, callback) {
+function decorate(command, argTypes) {
+  var d = function() {
+    API.prototype._command.call(this, command, Array.prototype.slice.call(arguments, 0));
+  };
+
+  d.argTypes = argTypes;
+
+  return d;
+};
+
+API.prototype._cmd_echo = function(str, callback) {
   var self = this;
 
   return callback(null, str);
 };
 
-API.prototype.echo.argTypes =
-  [
+API.prototype.echo = decorate('echo', [
   ['str', 'string'],
   ['callback', 'function']
-  ];
+  ]);
 
-API.prototype.echoNumber = function echoNumber(num, callback) {
+API.prototype._cmd_echoNumber = function(num, callback) {
   var self = this;
 
   return callback(null, num);
 };
 
-API.prototype.echoNumber.argTypes =
-  [
+API.prototype.echoNumber = decorate('echoNumber', [
   ['num', 'number'],
   ['callback', 'function']
-  ];
+  ]);
 
-API.prototype.echoObject = function echoNumber(obj, callback) {
+API.prototype._cmd_echoObject = function(obj, callback) {
   var self = this;
 
   return callback(null, obj);
 };
 
-API.prototype.echoObject.argTypes =
-  [
+API.prototype.echoObject = decorate('echoObject', [
   ['obj', 'object'],
   ['callback', 'function']
-  ];
+  ]);
 
 /*
 API.prototype.getBalance = function(callback) {
@@ -138,7 +145,7 @@ API.prototype.getBalance.argTypes =
   ];
 */
 
-API.prototype.getArgTypes = function getArgTypes(command, callback) {
+API.prototype._cmd_getArgTypes = function(command, callback) {
   var self = this;
 
   if (command[0] == '_' || typeof API.prototype[command] != 'function')
@@ -149,13 +156,12 @@ API.prototype.getArgTypes = function getArgTypes(command, callback) {
   return callback(null, argTypes);
 };
 
-API.prototype.getArgTypes.argTypes =
-  [
+API.prototype.getArgTypes = decorate('getArgTypes', [
   ['command', 'string'],
   ['callback', 'function']
-  ];
+  ]);
 
-API.prototype.getCommands = function getCommands(callback) {
+API.prototype._cmd_getCommands = function(callback) {
   var self = this;
 
   var fs = [];
@@ -169,29 +175,26 @@ API.prototype.getCommands = function getCommands(callback) {
   return callback(null, fs);
 };
 
-API.prototype.getCommands.argTypes =
-  [
+API.prototype.getCommands = decorate('getCommands', [
   ['callback', 'function']
-  ];
+  ]);
 
-API.prototype.getPublicKeyRingId = function getPublicKeyRingId(callback) {
+API.prototype._cmd_getPublicKeyRingId = function(callback) {
   var self = this;
 
   return callback(null, self.wallet.publicKeyRing.walletId);
 };
 
-API.prototype.getPublicKeyRingId.argTypes =
-  [
+API.prototype.getPublicKeyRingId = decorate('getPublicKeyRingId', [
   ['callback', 'function']
-  ];
+  ]);
 
-API.prototype.help = function help(callback) {
-  this.getCommands.apply(this, arguments);
+API.prototype._cmd_help = function(callback) {
+  this._cmd_getCommands.apply(this, arguments);
 };
 
-API.prototype.help.argTypes =
-  [
+API.prototype.help = decorate('help', [
   ['callback', 'function']
-  ];
+  ]);
 
 module.exports = require('soop')(API);
diff --git a/bin/copay b/bin/copay
index dced11f5f..2721da0e2 100755
--- a/bin/copay
+++ b/bin/copay
@@ -20,14 +20,31 @@ var main = function() {
   var args = commander.args;
 
   try {
-    api._command(args[0], args.slice(1), function(err, result) {
+    var command = args[0];
+    var commandArgs = args.slice(1);
+
+    if (command[0] == '_' || typeof api[command] != 'function')
+      throw new Error('invalid command');
+
+    api[command].apply(api, commandArgs.concat([function(err, result) {
       if (err)
         return console.log("" + err);
       
       console.log(JSON.stringify(result, null, 2));
-    });
-  } catch (err) {
-    console.log("" + err);
+    }]));
+  } catch(err) {
+    if (err.toString() == 'Error: invalid command') {
+      console.log("" + err);
+    }
+    else if (err.toString() == 'Error: invalid arguments') {
+      console.log("" + err);
+      console.log('Arguments for ' + command + ':')
+      api.getArgTypes(command, function(err, result) {
+        console.log(JSON.stringify(result, null, 2));
+      });
+    }
+    else
+      throw (err);
   }
 };
 
diff --git a/test/test.API.js b/test/test.API.js
index 02541570f..5bf1edf28 100644
--- a/test/test.API.js
+++ b/test/test.API.js
@@ -61,7 +61,7 @@ describe('API', function() {
     it('should echo a number', function(done) {
       var api = new API();
       var num = 500;
-      api.echo(num, function(err, result) {
+      api.echoNumber(num, function(err, result) {
         result.should.equal(num);
         (typeof result).should.equal('number');
         done();
@@ -73,7 +73,7 @@ describe('API', function() {
     it('should echo an object', function(done) {
       var api = new API();
       var obj = {test:'test'};
-      api.echo(obj, function(err, result) {
+      api.echoObject(obj, function(err, result) {
         result.test.should.equal(obj.test);
         (typeof result).should.equal('object');
         done();
@@ -81,4 +81,53 @@ describe('API', function() {
     });
   });
 
+  describe('#getArgTypes', function() {
+    it('should get the argTypes of echo', function(done) {
+      var api = new API();
+      api.getArgTypes('echo', function(err, result) {
+        result[0][1].should.equal('string');
+        done();
+      });
+    });
+  });
+
+  describe('#getCommands', function() {
+    it('should get all the commands', function(done) {
+      var api = new API();
+      var n = 0;
+
+      for (var i in api)
+        if (i[0] != '_' && typeof api[i] == 'function')
+          n++;
+
+      api.getCommands(function(err, result) {
+        result.length.should.equal(n);
+        done();
+      });
+    });
+  });
+
+  describe('#getPublicKeyRingId', function() {
+    it('should get a public key ring ID', function(done) {
+      var api = new API();
+      api.getPublicKeyRingId(function(err, result) {
+        result.length.should.be.greaterThan(5);
+        done();
+      });
+    });
+  });
+
+  describe('#help', function() {
+    it('should call _cmd_getCommands', function(done) {
+      var api = new API();
+      api._cmd_getCommands = function(callback) {
+        (typeof arguments[0]).should.equal('function');
+        callback(null, ['item']);
+      }
+      api.help(function(err, result) {
+        result[0].should.equal('item');
+        done();
+      });
+    });
+  });
 });