This article will walk you through the process of building a Custom Flow. We assume that you already know the basic structure of a Flow. Please go through our articles about Triggers, Actions, and Queries for a better understanding.
To help your end-users set up integrations with different apps, you can create Guided Flows.
However, if your end-users want to create custom integrations, that is, with some specific apps for which you haven't created a Guided Flow, they can do that using Custom Flows.
You can use this article to educate your end-users on how to create Custom Flows on your Integration Marketplace.
Custom Flow Creation
You need at least two activities to create a Custom Flow. As an example, we will explain how to create a Custom Flow using the following two activities.
- Trigger: A Trigger is an event that starts from a trigger application and sends data to other apps. Each Flow must have exactly one Trigger, which must be the first step.
- Action: An Action is a step executed on the action application as a result of a trigger. An Action cannot be the first step of an integration.
A Flow will always have one Trigger, but it could have one or more Actions. In this guide, we will add one Trigger step and one Action step to our Custom Flow.
For the Trigger step, we will be using the Mailchimp app. And for the Action step, we will be using the Sendinblue app. In this example, we will create a Custom Flow on Sendinblue's Integration Marketplace. You can follow the similar process and create Custom Flows on any Marketplace.

Step 1: Go to the Integration Marketplace and click on '+ Create Flow' button under the Custom Flow heading.

You will be redirected to the Custom Flow Builder (shown above).
Adding a Trigger to the Custom Flow
The first step of a Custom Flow is to add a Trigger.

Step 2: Select the App Connector of the Trigger application. We'll select the Mailchimp app for the Trigger step.

Step 3: Next, select the event on the trigger application that will initiate the integration Flow.
We have selected the Subscriber Added operation. This means that whenever a subscriber is added in our Mailchimp account, the Mailchimp app will initiate a trigger for Integry.

Step 4: Connect your account. You can select an account from the list or add a new account by clicking the 'Add My Account' button (shown above).
You will be prompted to authorize the app to access the trigger app's account. In this case, we will authorize Sendinblue to access our Mailchimp account.
Configuring the Fields for the Trigger Step
Step 5: Next, you have to configure the field(s) for the Trigger step.

As seen in the above image, we have configured the List field For Mailchimp. This is a list of subscribers in the Mailchimp account we've connected to this Flow. Every time a new subscriber is created in our account, it gets added to this list.
Testing the Trigger Step
Next, you have to test the Trigger step to ensure that the Trigger and its fields are added correctly.

Step 6: Click on the 'Test' button.

Step 7: In the next step, carry out the operation on the Trigger App. This will initiate the Trigger and Integry will receive a notification for it. For example, we are being prompted to create a contact in Mailchimp (shown above).

Step 8: After carrying out the operation on the trigger application, you can come back to the Custom Flow Builder and view the test results. To view the details of the trigger received, click on the Trigger section to expand the test results.

Verify the data received via the trigger and click on 'Done' to continue.
Adding the Action
The next step is to add an Action against the Trigger step. In this example, we will add the Sendinblue app to the Action step. This means that the Action will be performed on Sendinblue whenever the Trigger is received.

Step 9: Search and select an App Connector for the Action step.

Step 10: Next, select the action to be performed.
This action will be performed on the Action app once the Trigger is received. For our example, we will select the Action Create Contact, as we want to create a contact on the Sendinblue app whenever a contact is created in Mailchimp.

Step 11: Next, you have to connect your account for the Action step.
Add and connect the account where the Action event will be carried out once the Trigger is received. Connecting an account will enable Integry to access the account and perform the Action.
Configuring the Fields for the Action Step

Step 12: Configure the fields for the Action step.
Testing the Action Step
The next step is to test the Action step.

Click on the 'Test' button.

If the Action is performed successfully on the action app, a success message is shown to you. You can click on this section to see the details of the performed action. Click on 'Done' once you're done testing the Action step.

By clicking on the '+ Add Step' button, you can add as many steps to your Custom Flow as you like.

Once you're done creating your Custom Flow, enable the Active toggle to publish your Custom Flow on the Marketplace.
Note: You must add at least one step that belongs to the Marketplace before publishing your Flow.
Viewing Your Custom Flow

Click on 'Back to Marketplace' to view your Flow.

Click on 'My Flows.'

Here, you can view all the Flows you've set up in your account.
Congratulations!
You're all done creating your Custom Flow.