The Start block

Start block

The Start block is automatically added to every new flow. It represents the starting point of your flow and will trigger blocks connected to its output port. You can add inputs that receive data from scenarios and Flow Module blocks, then send that data to your flow. The Start block can also receive webhook data from published flows.

Webhooks in Postman Flows will be deprecated and replaced with a new capability in Spring of 2025. Webhooks in Flows will remain available with Free, Basic, and Professional plans until Spring of 2025. Webhooks in Flows aren't available with Enterprise plans.

Inputs

The Start block has no input ports. However, you can add inputs that will receive data from a scenario or a Flow Module block. The Start block sends the inputs' values as a JSON object with key-value pairs. To learn more about Start block inputs, see Receive data with inputs.

Output

The Start block has output ports that trigger connected blocks. It can also send data defined by inputs you've added, or webhook data received from a published flow.

Setup

The Start block appears automatically on every new flow's canvas. A new Start block is connected to three buttons you can select to do the following:

The Start block can be set up to perform different tasks, described below.

Trigger blocks simultaneously

Connect the Start block's output port to any blocks you want to trigger simultaneously at the beginning of a flow's run. However, most blocks will trigger automatically when you run the flow or when they receive data from another block.

Receive data with inputs

You can add inputs to the Start block to receive data from a scenario or a Flow Module block. Each input inserts a named data block into the Start block with a corresponding output port. When you run the flow, the Start block sends each input's data.

When a Flow Module block references a flow with inputs in its Start block, these inputs appear as named input ports in the Flow Module block. You can pass data from other blocks to these ports, and the Flow Module block will send the data to the corresponding inputs in the referenced flow's Start block. To learn more, read about the Flow Module block.

You can also assign values to Start block inputs using scenarios. To learn more, see Assign input values with scenarios.

To add an input to the Start block, do the following:

  1. In the Start block, select Add input Add input. A String block is inserted into the Start block.

  2. (Optional) Select the dropdown list to choose a different data block.

    Select data type

  3. Enter a name for the input.

Allow input of any type

By default, the Start block will send input data provided by scenarios. You can also enable the Start block to accept any inputs. This will deactivate scenarios and cause the Start block to send only received webhook data, or no data. To stop using scenarios and placeholder data, do the following:

  1. Select the Start block, then select Additional settings Additional Settings.

  2. Select the switch next to Allow input of any type.

Last modified: 2025/01/22

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