Creating a Send SMS Action on a Workflow Task

A Send SMS action lets you send templated text messages to members as part of an automated workflow. You can send a one-off message, or optionally start a full AI-powered SMS conversation using a workflow.

How it fits together: "Send SMS" is an Action type in Gravity Rail. Attach it to a workflow task as an entry action — when a member enters the task, the SMS fires automatically. Pair it with a Scheduled Event to send messages to a targeted group on a schedule.

Prerequisites

• A workflow with at least one task (see Workflows)
• A phone number configured in your workspace (see Phone & Voice) — this is the number the SMS is sent from
• Your workspace must have Twilio configured for SMS delivery

Steps

1. Open your workflow

Navigate to Workflows and open the workflow you will use. If you don't have one yet, create a new workflow and add at least one task.

2. Navigate to the Actions page

Go to Actions in your workspace.

3. Create a new action

Click New Action.

4. Configure the trigger

Set the trigger to Task Entered and select the task from your workflow. The SMS fires when a member enters this task.

5. Select "Send SMS" as the action type

In the action type dropdown, select Send SMS. The SMS configuration form will appear.

6. Select the phone number

Choose the phone number that will send the SMS from the Phone Number dropdown. This determines the "from" number that the member sees. If no phone numbers are listed, you need to configure one first in your workspace's phone settings.

7. Enter the message template

In the Message field, enter your SMS text. You can use template variables for personalization:

Hi {{member.first_name}}, this is a reminder about your appointment tomorrow. Reply to this message if you need to reschedule.

The template editor supports the same variables as email templates. See Template Variables for the full list.

8. Optionally start a conversation

Check Start a conversation after sending if you want the SMS to begin an AI-powered conversation:

1. Select a Workflow — this workflow will handle the member's replies
2. Optionally enter an Initial Message — a message sent as the user's first message to kick off the workflow

When this option is enabled, a new SMS chat is created for the member with the selected workflow. The member's replies are handled by the AI agent.

When this option is disabled, the SMS is sent as a one-off message with no conversation attached.

9. Save the action

Click Save. The action is now linked to your workflow task and will fire whenever a member enters that task.

Template Variables

You can personalize the message with template variables using {{variable}} syntax:

For the full list of available variables, see Template Variables.

SMS Tips

• Keep it short — SMS messages are limited to 160 characters per segment. Longer messages are split into multiple segments, which may increase cost.
• Include opt-out language — Depending on your use case and region, you may need to include instructions for opting out (e.g., "Reply STOP to unsubscribe").
• Use conversation mode for two-way interactions — If you expect the member to reply, enable "Start a conversation" so replies are handled by your workflow.
• Test first — Create a test member with your own phone number and run the action to verify the message looks correct before sending to real members.