Voice AI Custom Variables in Prompts for Sparkforge

By Sparkforge Support Team ·Last reviewed May 3, 2026

Sparkforge Voice AI prompts now accept custom variables such as {{contact.name}}. Add them under Agent Goals > Advanced Goals so the agent references real contact data on every call.

Sparkforge Voice AI prompts accept custom variables that pull from the contact record. The agent can address callers by name and reference their phone or other stored fields, so conversations sound personal instead of generic.

Add Custom Variables to a Prompt

Open Voice AI settings inside Sparkforge and select the agent you want to update.
Open Agent Goals.
Open Advanced Goals.
Pick variables from the available tag list, or insert them manually using the format {{contact.name}}.
Save the prompt and run a test call to verify the variables populate correctly.
Deploy the agent.

Available Variables

Use system-defined variables tied to contact fields, including:

{{contact.name}} — caller's full name
{{contact.phone}} — phone number on file
Other predefined contact fields for stored customer data

Best Practices

Keep prompts natural. Use variables only where they add value. Overloading prompts with variables makes the agent sound robotic.
Test before deploying. Run a test call to confirm each variable resolves to the expected data.
Keep contact data current. The variable pulls whatever is stored on the contact record, so stale data results in stale conversations.

Frequently Asked Questions

Which custom variables work in Voice AI prompts?

System-defined contact variables such as {{contact.name}} and {{contact.phone}}, plus other predefined contact fields. Browse the tag list under Advanced Goals.

Does this work on every Voice AI agent?

Yes. Custom variable support applies to all Voice AI agents configured with Advanced Goals.

Can I create my own custom variables?

Currently you can use system-defined variables tied to contact fields. Additional variable types may be supported in future updates.

How do I confirm the variables are resolving correctly?

Place a test call to the agent after saving the prompt. The agent should reference the contact data — if it does not, double-check the variable syntax and contact record.