diff --git a/README.md b/README.md
index 84bd081..f873299 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ You can install the package via pip:
 pip install vapi_python
 ```
 
-On Mac, you might need to install `brew install portaudio` to satisfy `pyaudio`'s dependency requirement. 
+On Mac, you might need to install `brew install portaudio` to satisfy `pyaudio`'s dependency requirement.
 
 ## Usage
 
@@ -31,7 +31,9 @@ You can start a new call by calling the `start` method and passing an `assistant
 ```python
 vapi.start(assistant_id='your-assistant-id')
 ```
+
 or
+
 ```python
 assistant = {
   'firstMessage': 'Hey, how are you?',
@@ -45,7 +47,21 @@ assistant = {
 vapi.start(assistant=assistant)
 ```
 
-The `start` method will initiate a new call. 
+The `start` method will initiate a new call.
+
+You can override existing assistant parameters or set variables with the `assistant_overrides` parameter.
+Assume the first message is `Hey, {{name}} how are you?` and you want to set the value of `name` to `John`:
+
+```python
+assistant_overrides = {
+  "recordingEnabled": False,
+  "variableValues": {
+    "name": "John"
+  }
+}
+
+vapi.start(assistant_id='your-assistant-id', assistant_overrides=assistant_overrides)
+```
 
 You can stop the session by calling the `stop` method:
 
@@ -80,5 +96,3 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 ```
-
-
diff --git a/README.rst b/README.rst
index f27df0f..fe0672c 100644
--- a/README.rst
+++ b/README.rst
@@ -75,7 +75,21 @@ or
 
    vapi.start(assistant=assistant)
 
-The `start` method will initiate a new call. 
+The `start` method will initiate a new call.
+
+You can override existing assistant parameters or set variables with the `assistant_overrides` parameter.
+Assume the first message is `Hey, {{name}} how are you?` and you want to set the value of `name` to `John`:
+
+.. code-block:: python
+
+   assistant_overrides = {
+      "recordingEnabled": False,
+      "variableValues": {
+         "name": "John"
+      }
+   }
+
+   vapi.start(assistant_id='your-assistant-id', assistant_overrides=assistant_overrides)
 
 You can stop the session by calling the `stop` method:
 
diff --git a/setup.py b/setup.py
index ed5e1e5..1ed5194 100644
--- a/setup.py
+++ b/setup.py
@@ -49,6 +49,6 @@ def read_requirements(file):
     test_suite='tests',
     tests_require=test_requirements,
     url='https://github.com/jordan.cde/vapi_python',
-    version='0.1.8',
+    version='0.1.9',
     zip_safe=False,
 )
diff --git a/vapi_python/vapi_python.py b/vapi_python/vapi_python.py
index 44fe220..e081934 100644
--- a/vapi_python/vapi_python.py
+++ b/vapi_python/vapi_python.py
@@ -27,12 +27,24 @@ def __init__(self, *, api_key, api_url="https://api.vapi.ai"):
         self.api_key = api_key
         self.api_url = api_url
 
-    def start(self, *, assistant_id=None, assistant=None):
+    def start(
+        self,
+        *,
+        assistant_id=None,
+        assistant=None,
+        assistants=None,
+        assistant_override=None,
+        assistant_overrides=None,
+    ):
         # Start a new call
         if assistant_id:
-            assistant = {'assistantId': assistant_id}
+            assistant = {'assistantId': assistant_id, 'assistantOverride': assistant_override}
         elif assistant:
-            assistant = {'assistant': assistant}
+            assistant = {'assistant': assistant, 'assistantOverride': assistant_override}
+        elif assistants:
+            assistant = {'assistants': assistants, 'assistantOverride': assistant_overrides, 'assistantOverrides': assistant_overrides}
+        else:
+            raise Exception("Error: No assistant specified.")
 
         call_id, web_call_url = create_web_call(
             self.api_url, self.api_key, assistant)