Preview Template

Preview how a template will render with sample variable values. Use this to test and validate your templates before starting a campaign.

Request Body

Field	Type	Required	Description
`template`	string	Yes	Template string to preview
`variables`	object	No	Sample variable values

Template Syntax

Templates use Jinja2-style syntax:

Syntax	Description
`{{variable}}`	Insert variable value
`{{variable\|filter}}`	Apply filter to variable
`{{variable\|default('fallback')}}`	Use fallback if missing

Available Filters

Filter	Description	Example
`phone_format`	Format phone number	`(555) 123-4567`
`title_case`	Capitalize words	`John Smith`
`upper`	UPPERCASE	`JOHN SMITH`
`lower`	lowercase	`john smith`
`default(value)`	Fallback value	Use if variable missing

System Variables

These are always available:

Variable	Default Value
`assistant_name`	`"your assistant"`
`company`	`"our company"`
`name`	`"there"`

Example Request

Request Body

{
  "template": "Hi {{name|title_case}}, this is {{assistant_name}} from {{company}}. I'm calling about your appointment on {{appointment_date}}.",
  "variables": {
    "name": "john smith",
    "assistant_name": "Sarah",
    "company": "Acme Healthcare",
    "appointment_date": "February 15th"
  }
}

Response

{
  "success": true,
  "rendered_template": "Hi John Smith, this is Sarah from Acme Healthcare. I'm calling about your appointment on February 15th."
}

Example with Missing Variables

Request with missing appointment_date:

Request Body

{
  "template": "Hi {{name|default('there')}}, your appointment is on {{appointment_date|default('your scheduled date')}}.",
  "variables": {
    "name": "John"
  }
}

Response

{
  "success": true,
  "rendered_template": "Hi John, your appointment is on your scheduled date."
}

Example Code

cURL

curl -X POST "https://api.burki.dev/api/v1/campaigns/template-preview" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "template": "Hi {{name}}, this is {{assistant_name}} calling.",
    "variables": {
      "name": "John",
      "assistant_name": "Sarah"
    }
  }'

Python

import requests

response = requests.post(
    "https://api.burki.dev/api/v1/campaigns/template-preview",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={
        "template": "Hi {{name|title_case}}, this is {{assistant_name}}.",
        "variables": {
            "name": "john smith",
            "assistant_name": "Sarah"
        }
    }
)

result = response.json()
if result["success"]:
    print(f"Preview: {result['rendered_template']}")
else:
    print("Template error occurred")

JavaScript

const response = await fetch("https://api.burki.dev/api/v1/campaigns/template-preview", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    template: "Hi {{name|title_case}}, this is {{assistant_name}}.",
    variables: {
      name: "john smith",
      assistant_name: "Sarah"
    }
  })
});

const result = await response.json();
if (result.success) {
  console.log(`Preview: ${result.rendered_template}`);
}

Template Examples

Welcome message:

Hi {{name|title_case}}, this is {{assistant_name}} from {{company}}. 
How are you today?

Appointment reminder:

I'm calling to remind you about your {{appointment_type|default('appointment')}} 
scheduled for {{appointment_date}} at {{appointment_time|default('your scheduled time')}}.

SMS message:

Hi {{name}}, reminder: You have an appointment at {{company}} on {{date}}. 
Reply CONFIRM to confirm or call us to reschedule.

Error Handling

If template has syntax errors:

Response (Error)

{
  "success": false,
  "rendered_template": "[Template Error: unexpected '}'...] Original template here..."
}

Best Practices

Always test templates before starting campaigns
Use default filters for optional variables
Keep templates concise - especially for SMS
Use title_case for names to handle different input formats
Test with empty variables to ensure fallbacks work

Authorizations

Authorization

string

header

required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Body

application/json

Request model for template preview.

template

string

required

Template string to preview

variables

Variables · object

required

Variables for template rendering

Response

Successful Response

API Documentation

Assistants

Assistant Phone Numbers

Assistant Documents (RAG)

Voice Cloning

Calls

Messaging

SIP Trunks

Billing

Phone Number Management

Call Data

Organization

Webhooks & System

Campaigns

WebSockets

Tools & Custom Actions

Conversation Flows

Learning & Memory

Request Body

Template Syntax

Available Filters

System Variables

Example Request

Response

Example with Missing Variables

Example Code

Template Examples

Error Handling

Best Practices

Authorizations

Body

Response

​Request Body

​Template Syntax

​Available Filters

​System Variables

​Example Request

​Response

​Example with Missing Variables

​Example Code

​Template Examples

​Error Handling

​Best Practices

Authorizations

Body

Response

Request Body

Template Syntax

Available Filters

System Variables

Example Request

Response

Example with Missing Variables

Example Code

Template Examples

Error Handling

Best Practices