Dynamic Variables & Prompt Validation

Dynamic variables inject user-specific context into the agent’s initial message and system prompt at runtime. Prompt validation checks that Jinja templates are syntactically correct before you save or test an agent.

Path

Manage Agent → Customize tab → Dynamic Variables

What Dynamic Variables Do

Dynamic Variables allow your AI agent to personalize its Initial Message and **System Prompt **using runtime data fetched from an external API. They replace placeholder text like:

{{user_name}}
{{plan_type}}
{{ticket_status}}

…with real values like:

Rahul
premium
pending

All before the request is sent to the LLM.

Why Use Dynamic Variables?

Personalizes the agent’s tone, message, and instructions
Ensures responses are relevant to the current user context
Allows the same agent to adapt dynamically for different users and use cases
Integrates with your backend systems for context-aware conversations

Where They’re Used

Dynamic Variables can be embedded in:

Initial Message – The very first thing the agent says
System Prompt – The underlying instruction set that guides the LLM

Placeholder Syntax

Always wrap variable names in double curly brackets
Use lowercase with underscores for clarity

Examples:

{{user_name}}
{{account_balance}}
{{ticket_status}}

How It Works

Agent Invoked User starts a chat or API-triggered interaction.
Variables Detected The system scans templates for {{variable_name}} placeholders.
API Call Made If variables exist, the agent calls your configured Dynamic Message API.
Values Returned API responds with a JSON object, e.g.:

{
	"user_name": "Rahul",
	"plan_type": "premium",
	"ticket_status": "pending"
}

Template Compiled

Placeholders are replaced with actual values.

LLM Receives Context

The prompt sent to the LLM is fully contextualized.

Example

System Prompt Template:

You are a support agent assisting {{user_name}}, a {{plan_type}} customer.
Their last ticket was marked {{ticket_status}}.

API Response:

{
	"user_name": "Rahul",
	"plan_type": "premium",
	"ticket_status": "pending"
}

Final Prompt Sent to LLM:

You are a support agent assisting Rahul, a premium customer.
Their last ticket was marked pending.

Best Practices

Area	Recommendation
Variable Naming	Use clear, lowercase, underscore-separated names
API Reliability	Ensure low-latency, high-uptime APIs
Defaults	Define fallback values for missing variables
Message Integrity	Keep variables simple — avoid complex objects
Testing	Test with real data before going live

Your system prompt is treated as a Jinja2 template. That supports conditionals and loops, but requires validation before you save or test an agent.

What validation checks

Syntax correctness for variables, if blocks, and for loops
Undeclared variables referenced in the prompt
Proper block closures (every opening tag has a matching closing tag)

Invalid syntax behavior

If syntax errors are found:

Save and Test are disabled
A clear error message is shown

Common errors:

Missing braces: {{ user_name }
Unclosed block: {% if condition %} ... (missing {% endif %})

Validation rules

Condition	Save / Test	Message
Valid syntax	Yes	–
Syntax error	No	”Invalid Jinja syntax.”
Missing variables at runtime	Yes (save works)	“Call triggered failed.”

Agent behavior

Existing agents keep working until the system prompt is edited and saved again.
New and updated agents must follow Jinja formatting rules.

Valid example

Hello {{ customer_name }}, your booking is on {{ booking_date }}.

Invalid example

Hello {{ customer_name }

Unclosed curly braces disable Save and Test until corrected.

Tip

If variables appear in the system prompt, declare them in pre-call variables or return them from the Dynamic Message API. Otherwise calls may fail at runtime.

Summary

Field	Value
Feature	Runtime variable injection
Syntax	`variable_name` with double curly braces
Input source	External API (JSON)
Supports	Initial message, system prompt, ending message
Resolved at	Runtime, before the LLM call
Failure handling	Graceful fallback

Gnani APIs

APIs

Use Cases

Dynamic Variables & Prompt Validation

Path

What Dynamic Variables Do

Why Use Dynamic Variables?

Where They’re Used

Placeholder Syntax

How It Works

Example

Best Practices

What validation checks

Invalid syntax behavior

Validation rules

Agent behavior

Valid example

Invalid example

Tip

Summary

​Path

​What Dynamic Variables Do

​Why Use Dynamic Variables?

​Where They’re Used

​Placeholder Syntax

​How It Works

​Example

​Best Practices

​Related feature: Prompt validation

​What validation checks

​Invalid syntax behavior

​Validation rules

​Agent behavior

​Valid example

​Invalid example

​Tip

​Summary

Path

What Dynamic Variables Do

Why Use Dynamic Variables?

Where They’re Used

Placeholder Syntax

How It Works

Example

Best Practices

Related feature: Prompt validation

What validation checks

Invalid syntax behavior

Validation rules

Agent behavior

Valid example

Invalid example

Tip

Summary