diff --git a/src/generator.coffee b/src/generator.coffee
index a9a1b1a..110ba29 100644
--- a/src/generator.coffee
+++ b/src/generator.coffee
@@ -58,6 +58,11 @@ validateParameters = (parameters, models, path, method) ->
         # only on put an post
         unless method?.toLowerCase() in ['put', 'post']
           throw new Error("#{errorPrefix} does not allowed body parameters - do you really knows http ?")
+
+        # only known dataType
+        allowedDataTypes = ['byte', 'boolean', 'int', 'long', 'float', 'double', 'string', 'date', 'file']
+        unless parameter.dataType?.toLowerCase() in allowedDataTypes or models[parameter.dataType]
+          throw new Error("'#{parameter.dataType}' does not match an allowed dataType [#{allowedDataTypes}] nor a known model [#{Object.keys(models)}]")
       when 'header', 'query'
         # nothing to check
       else
@@ -105,9 +110,9 @@ addRoutes = (descriptor, resources) ->
       throw new Error("Resource must contain 'api' attribute")
 
     # add models
-    if _.isObject(resource.api.models)
-      for id, model of resource.api.models
-        descriptor.models[id] = validateModel(model, id, descriptor.models)
+    resource.api.models or= {}
+    for id, model of resource.api.models
+      descriptor.models[id] = validateModel(model, id, descriptor.models)
 
     # allow api without controllers, but do not generate routes
     if _.isObject(resource.controller)
@@ -132,10 +137,21 @@ addRoutes = (descriptor, resources) ->
           unless _.isString(operation.nickname)
             throw new Error("Api #{api.path} operation #{operation.httpMethod} does not specify a nickname - we cannot guess the corresponding controller method")
           
+          # make sure the responseClass model is defined
+          if operation.responseClass
+            resource.api.models[operation.responseClass] or= descriptor.models[operation.responseClass]
+            unless resource.api.models[operation.responseClass]
+              throw new Error("responseClass #{operation.responseClass} doesn't match a model")
+
           # Validates parameters
           if _.isArray(operation.parameters)
             # parameter validations
             validateParameters(operation.parameters, descriptor.models, api.path, operation.httpMethod)
+
+            # make sure the dataType model is defined
+            for parameter in operation.parameters
+              if parameter.dataType
+                resource.api.models[parameter.dataType] or= descriptor.models[parameter.dataType]
           
           route = utils.pathToRoute(api.path)
           unless operation.nickname of resource.controller
@@ -199,7 +215,9 @@ module.exports = (app, descriptor, resources, options = {}) ->
     # Add descriptor to express application for other middlewares
     app.descriptor = descriptor
    catch err
-    throw new Error("Failed to create routes from resources: #{err.toString()}");
+     err2 = new Error("Failed to create routes from resources: #{err.toString()}")
+     err2.stack = err.stack
+     throw err2;
 
   # Express middleware for serving the descRoute.
   return (req, res, next) ->
@@ -225,4 +243,4 @@ module.exports = (app, descriptor, resources, options = {}) ->
       
       return res.json(result)
     
-    next()
\ No newline at end of file
+    next()
diff --git a/test/apiGeneration.coffee b/test/apiGeneration.coffee
index 76ca9a9..e0fb37b 100644
--- a/test/apiGeneration.coffee
+++ b/test/apiGeneration.coffee
@@ -456,6 +456,7 @@ describe 'API generation tests', ->
                 httpMethod: 'GET'
               ]
             ],
+            models: {},
             resourcePath: '/source'
           server.close()
           done()
@@ -475,10 +476,13 @@ describe 'API generation tests', ->
         .use(swagger.generator(app, 
           apiVersion: '1.0',
           basePath: root
-        , [
+        , [{
+          api: require './fixtures/addressApi.yml'
+          controller: passed: (req, res) -> res.json status: 'passed'
+        },{
           api: require './fixtures/complexApi.yml'
           controller: passed: (req, res) -> res.json status: 'passed'
-        ]))
+        }]))
         # use validator also because it manipulates models
         .use(swagger.validator(app))
       server = http.createServer app
@@ -491,7 +495,7 @@ describe 'API generation tests', ->
     it 'should reference models be untouched', (done) ->
       # when requesting the API description details
       request.get
-        url: 'http://'+host+':'+port+'/api-docs.json/example'
+        url: 'http://'+host+':'+port+'/api-docs.json/address'
         json: true
       , (err, res, body) ->
         return done err if err?
@@ -500,14 +504,14 @@ describe 'API generation tests', ->
         assert.deepEqual body,
           apiVersion: '1.0'
           basePath: '/api'
-          resourcePath: '/example'
+          resourcePath: '/address'
           apis: [
-            path: '/example'
+            path: '/address'
             operations: [
               httpMethod: 'POST'
               nickname: 'passed'
               parameters: [
-                dataType: 'User'
+                dataType: 'Address'
                 paramType: 'body'
                 required: true
               ]
@@ -524,18 +528,11 @@ describe 'API generation tests', ->
                 city:
                   type: 'string'
 
-            User:
-              id: 'User'
+            SomethingElse:
+              id: 'SomethingElse'
               properties:
-                id:
-                  type: 'int'
-                  required: true
                 name:
                   type: 'string'
-                addresses:
-                  type: 'array'
-                  items: 
-                    $ref: 'Address'
         done()
 
   describe 'given a properly configured and started server', ->
@@ -682,4 +679,5 @@ describe 'API generation tests', ->
                 nickname: 'remove'
               ]
             ]
-          done()
\ No newline at end of file
+            models: {}
+          done()
diff --git a/test/fixtures/addressApi.yml b/test/fixtures/addressApi.yml
new file mode 100644
index 0000000..087f6d4
--- /dev/null
+++ b/test/fixtures/addressApi.yml
@@ -0,0 +1,31 @@
+resourcePath: /address
+apis: 
+
+- path: /address
+  operations:
+
+  - httpMethod: POST
+    nickname: passed
+    parameters:
+
+    - dataType: Address
+      paramType: body
+      required: true
+
+models:
+
+  Address:
+    id: Address
+    properties:
+      zipcode:
+        type: long
+      street:
+        type: string
+      city:
+        type: string
+
+  SomethingElse:
+    id: SomethingElse
+    properties:
+      name:
+        type: string
diff --git a/test/fixtures/complexApi.yml b/test/fixtures/complexApi.yml
index 4e9e840..8a1a3fb 100644
--- a/test/fixtures/complexApi.yml
+++ b/test/fixtures/complexApi.yml
@@ -6,6 +6,7 @@ apis:
 
   - httpMethod: POST
     nickname: passed
+    responseClass: SomethingElse
     parameters:
 
     - dataType: User
@@ -14,16 +15,6 @@ apis:
 
 models:
 
-  Address:
-    id: Address
-    properties:
-      zipcode:
-        type: long
-      street:
-        type: string
-      city:
-        type: string
-
   User:
     id: User
     properties:
@@ -35,4 +26,4 @@ models:
       addresses:
         type: array
         items: 
-          $ref: Address
\ No newline at end of file
+          $ref: Address