In this section you design an Amazon Bedrock flow. Before designing a flow, we recommend that you read How Amazon Bedrock Flows works to familiarize yourself with concepts and terms in Amazon Bedrock Flows and to learn about the types of nodes that are available to you. For example flows that you can try, see Try example flows.
To build your flow
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Create a new flow by following the instructions at Create your first flow in Amazon Bedrock.
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In the flow builder section, the center pane (canvas) displays the flow. Delete the prompt node, if you don't need it.
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To add and configure nodes:
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In the Flow builder pane, select Nodes.
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Drag a node you want to use for the first step of your flow and drop it in the center pane.
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The circles on the nodes are connection points. To connect your flow input node to the second node, drag a line from the circle on the Flow input node to the circle in the Input section of the node you just added.
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Select the node you just added.
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In the Configure section of the Flow builder pane, provide the configurations for the selected node and define names, data types, and expressions for the inputs and outputs of the node.
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In the Flow builder pane, select Nodes.
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Repeat steps to add and configure nodes the remaining nodes in your flow.
Note
If you use a service role that Amazon Bedrock automatically created for you, the role will update with the proper permissions as you add nodes. If you use a custom service role however, you must add the proper permissions to the policy attached to your service role by referring to Create a service role for Amazon Bedrock Flows in Amazon Bedrock.
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Connect the Output of the last node in your flow with the Input of the Flow output node. You can have multiple Flow output nodes. To add additional flow output nodes, drag the Flow output node and drop it next to the node where you want the flow to stop. Make sure to draw connections between the two nodes.
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You can either continue to the next procedure to Test a flow in Amazon Bedrock or come back later. To continue to the next step, choose Save. To come back later, choose Save and exit.
Delete a node or a connection
During the process of building your flow, you might need to delete a node or remove node connections.
To delete a node
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Select a node you want to delete.
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In the Flow builder pane, choose the delete icon (
).Note
If you use a service role that Amazon Bedrock automatically created for you, the role will update with the proper permissions as you add nodes. If you delete nodes, however, the relevant permissions won't be deleted. We recommend that you delete the permissions that you no longer need by following the steps at Modifying a role.
To remove a connection
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In the Flow builder page, hover over the connection you want to remove until you see the expand icon and then drag the connection away from the node.
The following requirements apply to building a flow:
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Your flow must have only one flow input node and at least one flow output node.
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You can't include inputs for a flow input node.
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You can't include outputs for a flow output node.
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Every output in a node must be connected to an input in a downstream node (in the API, this is done through a FlowConnection with a FlowDataConnectionConfiguration).
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Every condition (including the default one) in a condition node must be connected to a downstream node (in the API, this is done through a FlowConnection with a FlowConditionalConnectionConfiguration).
The following pointers apply to building a flow:
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Begin by setting the data type for the output of the flow input node. This data type should match what you expect to send as the input when you invoke the flow.
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When you define the inputs for a flow using expressions, check that the result matches the data type that you choose for the input.
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If you include an iterator node, include a collector node downstream after you've sent the output through the nodes that you need. The collector node will return the outputs in an array.
