> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tigyai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Template Variables

> You can use Template Variables in your prompts for your Agent nodes, or when constructing the payload for the Webhook Node

### Template Rendering

You reference template variables with `{{double_brace}}` syntax. The data comes from [`initial_context`](/core-concepts/context-and-variables#initial_context), including values returned by a [Pre-Call Data Fetch](/voice-agent/pre-call-data-fetch), and from [`gathered_context`](/core-concepts/context-and-variables#gathered_context) in Webhook payloads.

**The syntax depends on where you use it:**

| Where                 | `initial_context`                      | `gathered_context`                |
| --------------------- | -------------------------------------- | --------------------------------- |
| Agent node prompts    | `{{field_name}}` (referenced directly) | Not available                     |
| Webhook Node payloads | `{{initial_context.field_name}}`       | `{{gathered_context.field_name}}` |

#### Agent node prompts

In an Agent node prompt, reference each `initial_context` field **directly by name**. Nested values are supported with dot notation.

Example: if the initial context is

```json theme={null}
{
    "initial_context": {
        "user": {
            "name": "John"
        }
    }
}
```

write your prompt to access the user's name as below:

Prompt: `You are Alice, who is talking to {{user.name}}.`

<Note>
  Variables extracted during the call (`gathered_context`) are **not** available in Agent prompts — a prompt can only reference `initial_context` fields. To act on extracted data, send it to a [Webhook Node](/voice-agent/webhook).
</Note>

#### Webhook Node payloads

When constructing a [Webhook Node](/voice-agent/webhook) payload, the context objects are nested under their names, so reference them with the `initial_context.` and `gathered_context.` prefixes:

Payload value: `{{initial_context.user.name}}` or `{{gathered_context.call_disposition}}`

### Using Template Variables for Testing

Template variables defined in your workflow **Settings > Context Variables** are included in test calls (both web and phone) made from the workflow editor. This is useful for simulating data that would normally come from telephony.

<img src="https://mintcdn.com/callguard/w-VUnJAq_m6hhmzP/images/template-variables.png?fit=max&auto=format&n=w-VUnJAq_m6hhmzP&q=85&s=5c1c77c71be2eac15287d3fb140fa673" alt="Template Variables panel in workflow Settings, showing a customer_name variable and fields to add new key/value pairs" style={{border: "1px solid #d1d5db", borderRadius: "8px", maxWidth: "100%"}} width="2254" height="1262" data-path="images/template-variables.png" />

For example, you can set `caller_number` and `called_number` as context variables to test [Pre-Call Data Fetch](/voice-agent/pre-call-data-fetch#testing-with-test-calls) without needing a real inbound call.

Browser voice tests use the same context model as inbound calls.

<Note>
  These context variables are only used during test calls from the workflow editor. On production inbound calls, the actual telephony data is used and these values are ignored.
</Note>

### Nodes

Tig.ai Voice Agents are composed of various nodes. These nodes provide instructions to the voice agent, configure inbound conversations, and send results to your systems with a [webhook](/voice-agent/webhook). In the next steps, we will document the nodes you can use to build the voice agent.