# Create a policy engine
<a name="policy-create-engine"></a>

A policy engine is a collection of policies that evaluates and authorizes agent tool calls. When associated with a gateway, the policy engine intercepts all agent requests and determines whether to allow or deny each action based on the defined policies.

**Topics**
+ [

## Prerequisites
](#policy-engine-prerequisites)
+ [

## Create a policy engine
](#create-policy-engine-methods)
+ [

## Using the policy engine ARN
](#policy-engine-arn-usage)

## Prerequisites
<a name="policy-engine-prerequisites"></a>

Before creating a policy engine, ensure you have a gateway setup. For more information, see [Building a gateway](https://docs.aws.amazon.com//bedrock-agentcore/latest/devguide/gateway-building.html).

## Create a policy engine
<a name="create-policy-engine-methods"></a>

The following shows how to create a policy engine.

**Example**  

1. Run the following code in a terminal to create a policy engine using the AWS CLI:

   ```
   aws bedrock-agentcore-control create-policy-engine \
     --name my_policy_engine \
     --description "My Policy Engine"
   ```

   The `policyEngineArn` in the response is the ARN to use when creating policies or associating with gateway.

1. The following Python code shows how to create a policy engine using the AWS Python SDK (Boto3):

   ```
   import boto3
   
   client = boto3.client('bedrock-agentcore-control')
   
   response = client.create_policy_engine(
       name='my_policy_engine',
       description='My Policy Engine'
   )
   
   print(f"Policy Engine ID: {response['policyEngineId']}")
   print(f"Policy Engine ARN: {response['policyEngineArn']}")
   ```

## Using the policy engine ARN
<a name="policy-engine-arn-usage"></a>

The `policyEngineArn` returned when creating a policy engine is used for two main purposes:
+  **Creating policies** - Use the ARN when adding policies to the engine
+  **Associating with gateways** - Use the ARN to enable policy enforcement on gateways

For more information about creating policies, see [Create a policy](policy-create-policies.md).