> ## Documentation Index
> Fetch the complete documentation index at: https://docs.itellico.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Variable Sources
> Understand where variables come from, when they're available, and where you can use them
Variables let you personalize your agent's greeting, prompt, and notifications with real data. This page explains where variables come from, when they become available, and where you can use them.
If you want the full lifecycle view, including how live tool inputs differ from post-call values, read [Conversation Data Flow](/build/conversation/runtime-data-flow).
## The Four Sources
| Source | When it's available | Example variables |
| ---------------------- | ----------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------- |
| **Contact data** | Before the call starts (if the caller matches a contact) | `{{contact.first_name}}`, `{{contact.email}}`, `{{contact.phone_number}}` |
| **Pre-call context** | Before the call starts (fetched from your API via [Dynamic Context](/build/advanced/dynamic-context)) | `{{account_tier}}`, `{{open_tickets}}`, `{{last_order_status}}` |
| **Built-in system** | Always available | `{{current_datetime}}`, `{{timezone}}`, `{{direction}}`, `{{agent_uuid}}` |
| **Post-call insights** | After the call ends (AI extracts from transcript) | `{{dyn_appointment_date}}`, `{{dyn_issue_summary}}`, `{{dyn_caller_sentiment}}` |
## Contact Variables
Available automatically when the caller's phone number matches a contact in your system.
```
Hi {{contact.first_name | default("there")}}, thanks for calling.
```
Use `| default("fallback")` so the greeting still works when no contact is matched.
**Available fields:** `contact.first_name`, `contact.last_name`, `contact.full_name`, `contact.email`, `contact.phone_number`
## Pre-Call Context (Dynamic Context)
Expert Mode
The platform fetches this from your API before the conversation starts. Configure the endpoint in **Call Flow → Before Call**.
Your API receives the caller's number and agent ID, and returns JSON. Every field in the response becomes a variable.
```
{% if account_tier == "enterprise" %}
This is a priority customer. Provide white-glove support.
{% else %}
Standard support flow.
{% endif %}
```
[Set up Dynamic Context →](/build/advanced/dynamic-context)
## Built-In System Variables
Always available in every conversation:
| Variable | What it contains |
| ---------------------- | ------------------------------------------------------- |
| `{{current_datetime}}` | Current date and time |
| `{{timezone}}` | Agent's configured timezone |
| `{{direction}}` | `inbound` or `outbound` |
| `{{medium}}` | Conversation channel, such as `voice`, `web`, or `test` |
| `{{agent_uuid}}` | The agent's unique ID |
| `{{agent_number}}` | The phone number the agent is using |
| `{{contact_number}}` | The caller's phone number |
## Post-Call Insight Variables
Available in [Notifications](/build/analytics/post-call-automation) after the call ends. AI extracts these from the transcript.
Type `{{dyn_` followed by a descriptive name:
```
{{dyn_appointment_date}} → AI finds the date mentioned
{{dyn_issue_summary}} → AI summarizes the problem
{{dyn_next_steps}} → AI identifies agreed action items
```
These only work in notification email templates, not in the agent's prompt (the call is already over).
## Where You Can Use Variables
| Location | Contact | Pre-call | System | Post-call |
| ----------------------- | -------------------- | -------- | ------------------------ | --------- |
| **Greeting message** | Yes | Yes | Yes | No |
| **Prompt** | Yes | Yes | Yes | No |
| **Notification emails** | Customer fields only | No | Conversation fields only | Yes |
Notification emails use a separate post-call context. They do not receive live-call variables like `{{contact.first_name}}`, Dynamic Context fields, `{{current_datetime}}`, or `{{timezone}}` directly. Use notification variables such as `{{customer_name}}`, `{{customer_email}}`, `{{customer_number}}`, `{{conversation_date}}`, `{{conversation_direction}}`, `{{conversation_summary}}`, and `{{dyn_*}}`.
## Syntax
Variables use Jinja syntax: `{{ variable_name }}`
**Filters:**
* `{{ contact.first_name | default("there") }}` — fallback value
* `{{ current_datetime | datetime("%H:%M") }}` — format dates
**Conditionals:**
```
{% if direction == "outbound" %}
You are making an outbound call to {{contact.first_name}}.
{% else %}
A customer is calling in.
{% endif %}
```
## Debugging Variables
If a variable isn't working:
1. Check the source — is the contact matched? Is Dynamic Context returning data?
2. Check spelling — variable names are case-sensitive
3. Check the fallback — use `| default("...")` for variables that might be empty
4. Test with different scenarios — inbound vs outbound, known vs unknown caller
## Next Steps
See how values move through the conversation lifecycle
Reference the full Jinja syntax and advanced patterns
Set up pre-call data fetching
Use post-call variables in email templates
Personalize greetings with variables