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

# Context and variables

> Use runtime context and template variables to pass known values into prompts, tools, and follow-up actions.

Use runtime context and template variables to pass known values into prompts, tools, and follow-up actions.

## Prerequisites

* A workflow with a saved draft.
* A clear list of values the workflow needs before and during a call.

## Configure runtime scope

1. Open a workflow and choose **Settings**.
2. Add the variable names that the workflow may use under **Template Variables**.
3. Reference a variable in a node prompt or tool field with double curly braces, such as `{{first_name}}`.
4. Test with representative initial context and confirm that extracted values appear after the relevant node.

## Runtime scope

Initial context is available at call start. Pre-call data can add to that context, while extraction can add values under gathered context during the conversation. Nested values can be addressed with paths such as `{{initial_context.account.tier}}`.

## Constraints and failure states

The workflow must receive a value before a template can produce useful output. Keep variable names consistent between the source, workflow settings, and node fields; use a default when a field supports one.

## Protect your data

Treat context as customer data. Send only the fields needed for the call and avoid putting secrets into prompts or transcript-visible values.

## Related

* [Template variables](/voice-agent/template-variables)
* [Pre-call data fetch](/voice-agent/pre-call-data-fetch)
* [Agent node](/voice-agent/agent)


## Related topics

- [Template variables](/voice-agent/template-variables.md)
- [Pre-call data fetch](/voice-agent/pre-call-data-fetch.md)
- [Knowledge base](/voice-agent/knowledge-base.md)
- [Agent node](/voice-agent/agent.md)
- [Tracing configuration](/configurations/tracing.md)