# Tutorial: Create a flow that processes mortgage applications
To get familiar with Amazon Bedrock resources and their capabilities, we'll use an CloudFormation template to set up a [flow](flows.md) that automates a mortgage application process processes by combining various Amazon Bedrock and other AWS resources.
**Note**
For this tutorial, we will use the *us-east-1* Region. You can use any Region that supports Agents, Flows, Guardrails, Knowledge bases, and Prompt management. For a table of feature support by Region, see [Feature support by AWS Region in Amazon Bedrock](features-regions.md). Make sure that you have permissions to create Amazon S3, Amazon Bedrock, Lambda, and DynamoDB resources in the Region that you use.
This flow isn't meant for deployment purposes, but rather to use as a tutorial to understand Amazon Bedrock resources. The following image is the visual representation of the flow in the AWS Management Console:
![\[Mortgage processing flow\]](http://docs.aws.amazon.com/bedrock/latest/userguide/images/cloudformation/mortgage-processing-flow.png)
The flow combines an Amazon Bedrock [agent](agents.md), [prompts](prompt-management.md), and a [Lambda function](https://docs.aws.amazon.com/lambda/latest/dg/welcome.html) to create a mortgage processing flow that intakes customer financial information and processes whether the customer qualifies for a loan. An Amazon Bedrock [knowledge base](knowledge-base.md) and [guardrail](guardrails.md) are also attached to the flow's agent to augment responses and to provide safeguards. For more detailed information about the components of the flow, see [Details about the mortgage processing flow](getting-started-mortgage-flow-details.md).
**Topics**
+ [Prerequisites](#getting-started-mortgage-flow-prereqs)
+ [Create the mortgage processing flow using CloudFormation](#getting-started-mortgage-flow-create)
+ [Test the mortgage processing flow](#getting-started-mortgage-flow-test)
+ [Clean up: deleting resources](#getting-started-mortgage-flow-delete)
+ [CloudFormation templates](getting-started-mortgage-flow-template.md)
+ [Details about the mortgage processing flow](getting-started-mortgage-flow-details.md)
## Prerequisites
To create this flow, you'll download a .zip file and follow instructions to run a script that will set up your resources and template for you.
**Important**
You'll be billed for the Amazon resources that you create until you delete them.
Then, complete the following prerequisites:
1. Download the [cloudformation-mortgage-flow-setup.zip](samples/cloudformation-mortgage-flow-setup.zip) file.
1. Unzip the file. You can learn more about the contents at [CloudFormation templates](getting-started-mortgage-flow-template.md).
1. Request access to Amazon Bedrock foundation models by doing the following:
1. Sign in to the AWS Management Console with an IAM identity that has permissions to use the Amazon Bedrock console. Then, open the Amazon Bedrock console at [https://console.aws.amazon.com/bedrock](https://console.aws.amazon.com/bedrock).
1. Make sure that you're in the **US East (N. Virginia)** Region by checking your Region in the upper-right corner. If you're not, switch Regions.
1. Select **Model access** at the bottom of the left navigation pane.
1. Choose **Modify model access**.
1. Do one of the following:
+ To request access to all models, choose **Enable all models**. On the page you're taken to, the checkboxes next to all the models will be filled.
+ To request access to specific models, choose **Enable specific models**. On the page you're taken to, you have the following options:
+ To request access to all models by a provider, select the checkbox next to the provider name.
+ To request access to one model, select the checkbox next to the model name.
1. For the purposes of the following tutorial, you should minimally request access to the **Titan Embeddings G1 - Text** and **Claude 3 Haiku** models. Then choose **Next**.
1. Review the models that you're requesting access to and the **Terms**. When you're ready, choose **Submit** to request access.
## Create the mortgage processing flow using CloudFormation
To create the mortgage processing flow and its associated resources, we'll create a CloudFormation template and use it to create a stack containing Amazon Bedrock resources.
**Important**
You'll be billed for the Amazon resources that you create until you delete them.
### Create the resources and CloudFormation template file
First, use the script from the .zip file to upload the resources to an S3 bucket and to create the CloudFormation templates.
1. In a terminal, run the following command to copy the resources into an Amazon S3 bucket and populate the `main-stack.yaml` and `main-stack.json` files with the S3 bucket name as the default value for the bucket name parameter.
```
bash deploy.sh
```
**Note**
The usage of the script is `bash deploy.sh `, where ** and ** are optional arguments. If you don't provide them, the following default values will be used:
** – The default AWS Region specified in your AWS credentials setup.
** – The bucket will be named *mortgage-flow-deployment--*, where ** is your AWS account ID and ** matches the value you provide or the default AWS Region specified in your AWS credentials setup.
1. Confirm the prompts. After the deployment is complete, you should have a complete `main-stack.yaml` and `main-stack.json` template for the next step.
**Note**
If the script fails, you can manually prepare the resources by doing the following:
Upload the *contents* (don't include the folder itself) of the unzipped `cloudformation-mortgage-flow-setup` folder to an S3 bucket in US East (N. Virginia) in the Amazon S3 console at [https://console.aws.amazon.com/s3/](https://console.aws.amazon.com/s3/).
Find the `templates/json/main-stack-tmp.yaml` or `templates/json/main-stack-tmp.json` file and do the following:
Change the `Default` value of the `Q01pS3BucketName` parameter from *MortgageFlowBucket* to your S3 bucket name.
Remove `-tmp` from the file name, such that it becomes `templates/json/main-stack.yaml` or `templates/json/main-stack.json`.
### Create the stack by using the CloudFormation console
Next, use the template you've saved to provision a CloudFormation stack.
1. Open the CloudFormation console at [https://console.aws.amazon.com/cloudformation](https://console.aws.amazon.com/cloudformation/). Make sure that you're in the **US East (N. Virginia)** Region by checking your Region in the upper-right corner. If you're not, switch Regions.
1. On the **Stacks** page, from the **Create stack** menu, choose **With new resources (standard)**.
1. Specify the template:
1. Under **Prerequisite**, choose **Choose an existing template**.
1. Under **Specify template**, choose **Upload a template file**.
1. Choose **Choose file**, navigate to the `main-stack.yaml` or the `main-stack.json` template, and select it.
1. Choose **Next**.
1. Specify the stack details:
1. In the **Stack name** field, enter a name for the stack.
1. In the **Parameters** field, leave the default values.
**Note**
The `Q01pS3BucketName` value should match the name of the S3 bucket to which you uploaded the resources for this template. The remaining arguments are related to the configurations of the knowledge base--if you modify any of them, make sure that the configurations are compatible with each other. For more information, see [Prerequisites for using a vector store you created for a knowledge base](knowledge-base-setup.md).
1. Choose **Next**.
1. Configure the stack options:
1. Under **Stack failure options**, choose **Delete all newly created resources**.
**Note**
Choosing this option prevents you from possibly being billed for resources whose deletion policy specifies they be retained even if the stack creation fails. For more information, see [`DeletionPolicy` attribute](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-deletionpolicy.html) in the *CloudFormation User Guide*.
1. Under **Capabilities**, check the box to acknowledge that CloudFormation might create IAM resources in your account.
1. Choose **Next**.
1. Review the stack details and choose **Submit**. CloudFormation creates the stack. The creation will take several minutes. After the stack creation is complete, you can use the **Resources** tab on the stack detail page to view the resources that where provisioned in your account.
1. After the stack creation completes, do the following to sync the data source for the knowledge base so that the knowledge base can be queried:
1. Sign in to the AWS Management Console with an IAM identity that has permissions to use the Amazon Bedrock console. Then, open the Amazon Bedrock console at [https://console.aws.amazon.com/bedrock](https://console.aws.amazon.com/bedrock).
1. From the left navigation pane, choose **Knowledge Bases** and then select the knowledge base that was created, named `AWSDocsTutorial-MortgageKB`.
1. In the **Data source** section, select the checkbox next to the data source that was created, named `AWSDocsTutorial-MortgageKB-DS`.
1. Choose **Sync**. After syncing completes, you can test the flow.
## Test the mortgage processing flow
Once the mortgage processing flow has been created, you can use the Amazon Bedrock console to examine, test, and modify the flow. You can also examine, test, and modify the individual resources in the flow.
**To test the flow**
1. Sign in to the AWS Management Console with an IAM identity that has permissions to use the Amazon Bedrock console. Then, open the Amazon Bedrock console at [https://console.aws.amazon.com/bedrock](https://console.aws.amazon.com/bedrock).
1. From the left navigation pane, choose **Flows**. Make sure that you're in the **US East (N. Virginia)** Region by checking your Region in the upper-right corner. If you're not, switch Regions.
1. In the **Flows** section, select the flow that was created from the CloudFormation template. It should be `AWSDocsTutorial-MortgageFlow`.
1. Choose **Edit in flow builder**. You can drag individual nodes in the flow to modify the visual representation of the flow.
1. In the **Test flow** pane, enter the following in the text field and then select **Run**.
```
{
"income": 80000,
"totalDebt": 5000,
"loanTerm": 30,
"loanAmount": 600000,
"creditScore": 750,
"mlsId": "MLS-5678"
}
```
Because the loan amount is greater than the calculated maximum affordable loan, the **incomeDebt** prompt is triggered and the flow generates a rejection letter. You can choose **Show trace** to see the nodes that were run in the flow.
1. Again, in the **Test flow** pane, enter the following in the text field and then select **Run**.
```
{
"income": 120000,
"totalDebt": 5000,
"loanTerm": 30,
"loanAmount": 200000,
"creditScore": 650,
"mlsId": "MLS-3456"
}
```
Because the loan amount is less than the calculated maximum affordable loan, the **processApplication** prompt is triggered and sent to the **mortgageProcessingAgent**, which looks up the attached knowledge base and generates a response that assesses, based on the input values, whether the customer qualifies for a loan.
1. (Optional) Try running the flow by using different values for the fields in the JSON object. The `mlsId` values correspond to properties listed on the Multiple Listing Service. You can find valid `mlsId` values by doing the following:
1. Sign in to the AWS Management Console and open the DynamoDB console at [https://console.aws.amazon.com/dynamodb/](https://console.aws.amazon.com/dynamodb/).
1. In the left navigation pane, select **Tables**.
1. Select the table that says **AWSDocsTutorial-PropertyListing**.
1. Choose **Explore table items**.
1. You can use any of the values in the **mls\$1id** column in the flow input.
You can also navigate to the **Agents**, **Knowledge Bases**, **Guardrails**, and **Prompt management** pages in the AWS Management Console to examine each Amazon Bedrock resource used in the flow, independently. To learn more about the flow and understand the components in more detail, see [Details about the mortgage processing flow](getting-started-mortgage-flow-details.md).
## Clean up: deleting resources
After you explore the resources and have a better understanding of the capabilities of different Amazon Bedrock resources, we'll delete the stack and the resources it contains.
**Important**
You'll be billed for the Amazon resources that you create until you delete them.
1. Open the [https://console.aws.amazon.com/cloudformation](https://console.aws.amazon.com/cloudformation/).
1. From the left navigation pain, choose **Stacks**.
1. Choose the stack that you created from the template. Then choose **Delete**, then confirm **Delete**.
CloudFormation initiates deletion of the main stack, all its nested stacks, and all resources included in the stacks.