Ciaran
04/09/2026, 8:43 AMAI Evy
04/09/2026, 8:43 AMAI Evy
04/09/2026, 8:43 AMAI Evy
04/09/2026, 8:43 AMAI Evy
04/09/2026, 8:43 AMAI Evy
04/09/2026, 8:43 AMCiaran
04/09/2026, 8:47 AMAI Evy
04/09/2026, 8:47 AMAI Evy
04/09/2026, 8:47 AMAI Evy
04/09/2026, 8:47 AMAI Evy
04/09/2026, 8:47 AMCiaran
04/09/2026, 9:09 AMAI Evy
04/09/2026, 9:09 AMAI Evy
04/09/2026, 9:09 AMAI Evy
04/09/2026, 9:09 AMAI Evy
04/09/2026, 9:10 AMCiaran
04/09/2026, 9:54 AMAI Evy
04/09/2026, 9:54 AMAI Evy
04/09/2026, 9:54 AM{{variable_name}} exists - Returns true if the variable is defined and has a value
- {{variable_name}} does not exists - Returns true if the variable is undefined
For your authentication scenario:
Set up your Global Node's transition condition with an equation like:
{{authenticated_user}} exists
This ensures the Global Node is only accessible after authentication is complete and the variable is set.
Why single agent is better:
Using one agent with conditional Global Nodes is more efficient than two agents because:
- Maintains conversation context throughout
- Simpler architecture to manage
- No need for agent handoff logic
- Variables persist across the entire conversation flow
The equation-based conditions provide the control you need without the complexity of multiple agents.AI Evy
04/09/2026, 9:54 AMAI Evy
04/09/2026, 9:54 AMCiaran
04/09/2026, 9:57 AMAI Evy
04/09/2026, 9:57 AMAI Evy
04/09/2026, 9:58 AM{{user_id}} variable exists. [(1) ]()
How to set it up:
When you enable a Global Node, you must define the condition to transition into it. For your delivery Global Node, you need to add **two conditions**:
1. **Prompt condition**: "The user asks how we deliver"
2. **Equation condition**: {{user_id}} exists
Implementation details:
The equation condition {{user_id}} exists returns true if the variable is defined and has a value (even an empty string is considered having a value) .
All equation conditions are evaluated first, and then the prompt conditions are evaluated. This means Retell will first check if {{user_id}} exists, and only if it does will it evaluate whether the user is asking about delivery.
To add this in the dashboard:
Click on your Global Node, then click the "+" button to add a transition condition. Choose "equation" and add {{user_id}} exists. You can change "ANY" to "ALL" to force all equations to be true instead of just one.
This approach keeps everything in a single agent while ensuring the delivery information is only accessible after authentication sets the {{user_id}} variable.AI Evy
04/09/2026, 9:58 AMAI Evy
04/09/2026, 9:58 AMCiaran
04/09/2026, 9:59 AMAI Evy
04/09/2026, 9:59 AMAI Evy
04/09/2026, 9:59 AMAI Evy
04/09/2026, 9:59 AMAI Evy
04/09/2026, 9:59 AMCiaran
04/09/2026, 10:02 AMAI Evy
04/09/2026, 10:02 AMAI Evy
04/09/2026, 10:02 AMAI Evy
04/09/2026, 10:02 AMAI Evy
04/09/2026, 10:02 AMCiaran
04/09/2026, 10:04 AMAI Evy
04/09/2026, 10:04 AMAI Evy
04/09/2026, 10:04 AMAI Evy
04/09/2026, 10:04 AMAI Evy
04/09/2026, 10:04 AMCiaran
04/09/2026, 11:00 AMAI Evy
04/09/2026, 11:00 AMAI Evy
04/09/2026, 11:00 AMAI Evy
04/09/2026, 11:00 AMAI Evy
04/09/2026, 11:00 AMCiaran
04/09/2026, 4:01 PMAI Evy
04/09/2026, 4:01 PMAI Evy
04/09/2026, 4:01 PMAI Evy
04/09/2026, 4:01 PMAI Evy
04/09/2026, 4:01 PMCiaran
04/09/2026, 4:06 PMAI Evy
04/09/2026, 4:06 PMAI Evy
04/09/2026, 4:07 PM{{customer_phone}})
To fix your issue:
Check your SMS node or Send SMS tool configuration and verify the SMS destination setting. If you're using a dynamic variable like {{customer_phone}}, ensure that: [(3) ]()
- The variable is being set correctly earlier in your flow
- The variable contains the correct phone number format
- The variable actually exists (you can use {{variable_name}} exists to check)
Important note about chat testing:
When testing via chat instead of an actual phone call, the system variables like {{user_number}} may not behave the same way as they would in a live phone call. The {{user_number}} variable represents the user's phone number (from_number for inbound, to_number for outbound) .
To troubleshoot:
1. Check which destination is configured in your SMS node/tool
2. If using a dynamic variable, verify it's populated with the correct number
3. Test with an actual phone call rather than chat to ensure proper variable population
Dynamic variables work in SMS configurations for both the content and destination. [(1) ]() [(2) ]()AI Evy
04/09/2026, 4:07 PMAI Evy
04/09/2026, 4:07 PMCiaran
04/09/2026, 4:08 PMAI Evy
04/09/2026, 4:08 PMAI Evy
04/09/2026, 4:08 PMAI Evy
04/09/2026, 4:08 PMAI Evy
04/09/2026, 4:08 PMCiaran
04/09/2026, 4:58 PMAI Evy
04/09/2026, 4:58 PMAI Evy
04/09/2026, 4:59 PM{{user_number}}) .
Check out these potentially useful sources:
- [SMS Node]()
- [Documentation]()AI Evy
04/09/2026, 4:59 PMAI Evy
04/09/2026, 4:59 PM