# Run Amazon Bedrock Flows code samples
<a name="flows-code-ex"></a>

The following code samples assume that you've fulfilled the following prerequisites:

1. Set up a role to have permissions to Amazon Bedrock actions. If you haven't, refer to [Quickstart](getting-started.md).

1. Set up your credentials to use the AWS API. If you haven't, refer to [Get started with the API](getting-started-api.md).

1. Create a service role to carry out flow-related actions on your behalf. If you haven't, refer to [Create a service role for Amazon Bedrock Flows in Amazon Bedrock](flows-permissions.md).

To create a flow, send a [CreateFlow](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_CreateFlow.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt). For example code, see [Run Amazon Bedrock Flows code samples](#flows-code-ex)

The following fields are required:


****  

| Field | Basic description | 
| --- | --- | 
| name | A name for the flow. | 
| executionRoleArn | The ARN of the [service role with permissions to create and manage flows](flows-permissions.md). | 

The following fields are optional:


****  

| Field | Use case | 
| --- | --- | 
| definition | Contains the nodes and connections that make up the flow. | 
| description | To describe the flow. | 
| tags | To associate tags with the flow. For more information, see [Tagging Amazon Bedrock resources](tagging.md). | 
| customerEncryptionKeyArn | To encrypt the resource with a KMS key. For more information, see [Encryption of Amazon Bedrock Flows resources](encryption-flows.md). | 
| clientToken | To ensure the API request completes only once. For more information, see [Ensuring idempotency](https://docs.aws.amazon.com/ec2/latest/devguide/ec2-api-idempotency.html). | 

While the `definition` field is optional, it is required for the flow to be functional. You can choose to create a flow without the definition first and instead update the flow later.

For each node in your `nodes` list, you specify the type of node in the `type` field and provide the corresponding configuration of the node in the `config` field. For details about the API structure of different types of nodes, see [Node types for your flow](flows-nodes.md).

To try out some code samples for Amazon Bedrock Flows, choose the tab for your preferred method, and then follow the steps:

------
#### [ Python ]

1. Create a flow using a [CreateFlow](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_CreateFlow.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt) with the following nodes:
   + An input node.
   + A prompt node with a prompt defined inline that creates a music playlist using two variables (`genre` and `number`).
   + An output node that returns the model completion.

   Run the following code snippet to load the AWS SDK for Python (Boto3), create an Amazon Bedrock Agents client, and create a flow with the nodes (replace the `executionRoleArn` field with the ARN of your the service role that you created for flow):

   ```
   # Import Python SDK and create client
   import boto3
   
   client = boto3.client(service_name='bedrock-agent')
   
   # Replace with the service role that you created. For more information, see https://docs.aws.amazon.com/bedrock/latest/userguide/flows-permissions.html
   FLOWS_SERVICE_ROLE = "arn:aws:iam::123456789012:role/MyFlowsRole"
   
   # Define each node
   
   # The input node validates that the content of the InvokeFlow request is a JSON object.
   input_node = {
       "type": "Input",
       "name": "FlowInput",
       "outputs": [
           {
               "name": "document",
               "type": "Object"
           }
       ]
   }
   
   # This prompt node defines an inline prompt that creates a music playlist using two variables.
   # 1. {{genre}} - The genre of music to create a playlist for
   # 2. {{number}} - The number of songs to include in the playlist
   # It validates that the input is a JSON object that minimally contains the fields "genre" and "number", which it will map to the prompt variables.
   # The output must be named "modelCompletion" and be of the type "String".
   prompt_node = {
       "type": "Prompt",
       "name": "MakePlaylist",
       "configuration": {
           "prompt": {
               "sourceConfiguration": {
                   "inline": {
                       "modelId": "amazon.nova-lite-v1:0",
                       "templateType": "TEXT",
                       "inferenceConfiguration": {
                           "text": {
                               "temperature": 0.8
                           }
                       },
                       "templateConfiguration": { 
                           "text": {
                               "text": "Make me a {{genre}} playlist consisting of the following number of songs: {{number}}."
                           }
                       }
                   }
               }
           }
       },
       "inputs": [
           {
               "name": "genre",
               "type": "String",
               "expression": "$.data.genre"
           },
           {
               "name": "number",
               "type": "Number",
               "expression": "$.data.number"
           }
       ],
       "outputs": [
           {
               "name": "modelCompletion",
               "type": "String"
           }
       ]
   }
   
   # The output node validates that the output from the last node is a string and returns it as is. The name must be "document".
   output_node = {
       "type": "Output",
       "name": "FlowOutput",
       "inputs": [
           {
               "name": "document",
               "type": "String",
               "expression": "$.data"
           }
       ]
   }
   
   # Create connections between the nodes
   connections = []
   
   #   First, create connections between the output of the flow input node and each input of the prompt node
   for input in prompt_node["inputs"]:
       connections.append(
           {
               "name": "_".join([input_node["name"], prompt_node["name"], input["name"]]),
               "source": input_node["name"],
               "target": prompt_node["name"],
               "type": "Data",
               "configuration": {
                   "data": {
                       "sourceOutput": input_node["outputs"][0]["name"],
                       "targetInput": input["name"]
                   }
               }
           }
       )
   
   # Then, create a connection between the output of the prompt node and the input of the flow output node
   connections.append(
       {
           "name": "_".join([prompt_node["name"], output_node["name"]]),
           "source": prompt_node["name"],
           "target": output_node["name"],
           "type": "Data",
           "configuration": {
               "data": {
                   "sourceOutput": prompt_node["outputs"][0]["name"],
                   "targetInput": output_node["inputs"][0]["name"]
               }
           }
       }
   )
   
   # Create the flow from the nodes and connections
   response = client.create_flow(
       name="FlowCreatePlaylist",
       description="A flow that creates a playlist given a genre and number of songs to include in the playlist.",
       executionRoleArn=FLOWS_SERVICE_ROLE,
       definition={
           "nodes": [input_node, prompt_node, output_node],
           "connections": connections
       }
   )
   
   flow_id = response.get("id")
   ```

1. List the flows in your account, including the one you just created, by running the following code snippet to make a [ListFlows](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_ListFlows.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

   ```
   client.list_flows()
   ```

1. Get information about the flow that you just created by running the following code snippet to make a [GetFlow](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_GetFlow.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

   ```
   client.get_flow(flowIdentifier=flow_id)
   ```

1. Prepare your flow so that the latest changes from the working draft are applied and so that it's ready to version. Run the following code snippet to make a [PrepareFlow](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_PrepareFlow.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

   ```
   client.prepare_flow(flowIdentifier=flow_id)
   ```

1. Version the working draft of your flow to create a static snapshot of your flow and then retrieve information about it with the following actions:

   1. Create a version by running the following code snippet to make a [CreateFlowVersion](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_CreateFlowVersion.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      response = client.create_flow_version(flowIdentifier=flow_id)
                                      
      flow_version = response.get("version")
      ```

   1. List all versions of your flow by running the following code snippet to make a [ListFlowVersions](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_ListFlowVersions.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      client.list_flow_versions(flowIdentifier=flow_id)
      ```

   1. Get information about the version by running the following code snippet to make a [GetFlowVersion](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_GetFlowVersion.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      client.get_flow_version(flowIdentifier=flow_id, flowVersion=flow_version)
      ```

1. Create an alias to point to the version of your flow that you created and then retrieve information about it with the following actions:

   1. Create an alias and point it to the version you just created by running the following code snippet to make a [CreateFlowAlias](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_CreateFlowAlias.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      response = client.create_flow_alias(
          flowIdentifier=flow_id,
          name="latest",
          description="Alias pointing to the latest version of the flow.",
          routingConfiguration=[
              {
                  "flowVersion": flow_version
              }
          ]
      )
      
      flow_alias_id = response.get("id")
      ```

   1. List all aliases of your flow by running the following code snippet to make a [ListFlowAliass](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_ListFlowAliass.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      client.list_flow_aliases(flowIdentifier=flow_id)
      ```

   1. Get information about the alias that you just created by running the following code snippet to make a [GetFlowAlias](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_GetFlowAlias.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      client.get_flow_alias(flowIdentifier=flow_id, aliasIdentifier=flow_alias_id)
      ```

1. Run the following code snippet to create an Amazon Bedrock Agents Runtime client and invoke a flow. The request fills in the variables in the prompt in your flow and returns the response from the model to make a [InvokeFlow](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent-runtime_InvokeFlow.html) request with an [Agents for Amazon Bedrock runtime endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-rt):

   ```
   client_runtime = boto3.client('bedrock-agent-runtime')
   
   response = client_runtime.invoke_flow(
       flowIdentifier=flow_id,
       flowAliasIdentifier=flow_alias_id,
       inputs=[
           {
               "content": {
                   "document": {
                       "genre": "pop",
                       "number": 3
                   }
               },
               "nodeName": "FlowInput",
               "nodeOutputName": "document"
           }
       ]
   )
   
   result = {}
   
   for event in response.get("responseStream"):
       result.update(event)
   
   if result['flowCompletionEvent']['completionReason'] == 'SUCCESS':
       print("Flow invocation was successful! The output of the flow is as follows:\n")
       print(result['flowOutputEvent']['content']['document'])
   
   else:
       print("The flow invocation completed because of the following reason:", result['flowCompletionEvent']['completionReason'])
   ```

   The response should return a playlist of pop music with three songs.

1. Delete the alias, version, and flow that you created with the following actions:

   1. Delete the alias by running the following code snippet to make a [DeleteFlowAlias](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_DeleteFlowAlias.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      client.delete_flow_alias(flowIdentifier=flow_id, aliasIdentifier=flow_alias_id)
      ```

   1. Delete the version by running the following code snippet to make a [DeleteFlowVersion](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_DeleteFlowVersion.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      client.delete_flow_version(flowIdentifier=flow_id, flowVersion=flow_version)
      ```

   1. Delete the flow by running the following code snippet to make a [DeleteFlow](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_agent_DeleteFlow.html) request with an [Agents for Amazon Bedrock build-time endpoint](https://docs.aws.amazon.com/general/latest/gr/bedrock.html#bra-bt):

      ```
      client.delete_flow(flowIdentifier=flow_id)
      ```

------