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

# Prompt Templates

> Customize agent prompts with system, prompt, and response templates

Templates let you customize how agents construct their prompts - system instructions, user prompts, and response formats.

```mermaid theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
graph LR
    subgraph "Template Flow"
        System[📋 System Template] --> Prompt[💬 Prompt Template]
        Prompt --> LLM[🧠 LLM]
        LLM --> Response[📝 Response Template]
    end
    
    classDef template fill:#6366F1,stroke:#7C90A0,color:#fff
    classDef llm fill:#10B981,stroke:#7C90A0,color:#fff
    
    class System,Prompt,Response template
    class LLM llm
```

## Quick Start

<Steps>
  <Step title="Basic Templates">
    ```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
    from praisonaiagents import Agent, TemplateConfig

    agent = Agent(
        name="Custom Agent",
        instructions="You are a helpful assistant",  # System Prompt: defines agent identity
        templates=TemplateConfig(
            system="You are {role}. {instructions}",  # System Prompt template
            prompt="User request: {input}",  # User Prompt template
        )
    )
    ```
  </Step>

  <Step title="Response Format">
    ```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
    agent = Agent(
        name="Structured Agent",
        instructions="You provide structured answers",
        templates=TemplateConfig(
            response="""Format your response as:
    ## Summary
    [Brief summary]

    ## Details
    [Detailed explanation]

    ## Next Steps
    [Recommendations]"""
        )
    )
    ```
  </Step>
</Steps>

***

## Template Types

```mermaid theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
graph TB
    subgraph "Template Types"
        System[🔧 System<br/>Agent identity & rules]
        Prompt[💬 Prompt<br/>User input formatting]
        Response[📝 Response<br/>Output structure]
    end
    
    System -->|"Who am I?"| Agent[🤖 Agent]
    Prompt -->|"What to do?"| Agent
    Response -->|"How to answer?"| Agent
    
    classDef template fill:#189AB4,stroke:#7C90A0,color:#fff
    classDef agent fill:#10B981,stroke:#7C90A0,color:#fff
    
    class System,Prompt,Response template
    class Agent agent
```

| Template   | Purpose                        | When Applied          |
| ---------- | ------------------------------ | --------------------- |
| `system`   | Agent identity, rules, context | Start of conversation |
| `prompt`   | Format user input              | Each request          |
| `response` | Structure output format        | Each response         |

***

## Configuration Options

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
from praisonaiagents import TemplateConfig

config = TemplateConfig(
    system="You are {role}...",      # System Prompt: agent identity (WHO you are)
    prompt="Query: {input}",          # User Prompt: task input (WHAT to do)
    response="Format: ...",           # Response format (HOW to answer)
    use_system_prompt=True,           # Include system prompt
)
```

| Option              | Type   | Default | Description                  |
| ------------------- | ------ | ------- | ---------------------------- |
| `system`            | `str`  | `None`  | System prompt template       |
| `prompt`            | `str`  | `None`  | User prompt template         |
| `response`          | `str`  | `None`  | Response format template     |
| `use_system_prompt` | `bool` | `True`  | Whether to use system prompt |

***

## Template Variables

Templates support variable substitution:

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
agent = Agent(
    name="Support Agent",
    role="Customer Support Specialist",
    instructions="Help customers with their issues",
    templates=TemplateConfig(
        system="""You are {role}.
Your goal: {goal}
Background: {backstory}

{instructions}"""
    )
)
```

### Available Variables

| Variable         | Source             |
| ---------------- | ------------------ |
| `{name}`         | Agent name         |
| `{role}`         | Agent role         |
| `{goal}`         | Agent goal         |
| `{backstory}`    | Agent backstory    |
| `{instructions}` | Agent instructions |
| `{input}`        | User input         |

***

## Common Patterns

### Structured Output

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
agent = Agent(
    instructions="You analyze data",
    templates=TemplateConfig(
        response="""Provide your analysis in this format:

**Finding**: [Main finding]
**Evidence**: [Supporting data]
**Confidence**: [High/Medium/Low]
**Recommendation**: [Action to take]"""
    )
)
```

### Role-Based System

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
agent = Agent(
    name="Expert",
    role="Senior Software Engineer",
    backstory="10 years of experience in Python",
    templates=TemplateConfig(
        system="""# Role
You are {role} with the following background:
{backstory}

# Guidelines
{instructions}

# Constraints
- Always explain your reasoning
- Provide code examples when relevant
- Cite best practices"""
    )
)
```

### Chain-of-Thought

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
agent = Agent(
    instructions="You solve problems step by step",
    templates=TemplateConfig(
        response="""Think through this step by step:

1. **Understanding**: What is being asked?
2. **Analysis**: What are the key factors?
3. **Solution**: What is the answer?
4. **Verification**: Is this correct?

Final Answer: [Your answer]"""
    )
)
```

***

## Disabling System Prompt

For some use cases, you may want to skip the system prompt:

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
agent = Agent(
    instructions="...",
    templates=TemplateConfig(
        use_system_prompt=False  # No system prompt
    )
)
```

***

## Template Inheritance

Templates combine with agent properties:

```mermaid theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
graph TB
    Agent[Agent Properties] --> Merge[Merge]
    Template[Template Config] --> Merge
    Merge --> Final[Final Prompt]
    
    classDef source fill:#6366F1,stroke:#7C90A0,color:#fff
    classDef merge fill:#F59E0B,stroke:#7C90A0,color:#fff
    classDef final fill:#10B981,stroke:#7C90A0,color:#fff
    
    class Agent,Template source
    class Merge merge
    class Final final
```

```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
# Agent properties
agent = Agent(
    name="Helper",
    role="Assistant",
    instructions="Be helpful and concise",
    templates=TemplateConfig(
        system="{role}: {instructions}"
    )
)

# Results in: "Assistant: Be helpful and concise"
```

***

## Best Practices

<AccordionGroup>
  <Accordion title="Keep templates focused">
    Each template should have a clear purpose. Don't overload the system template.
  </Accordion>

  <Accordion title="Use response templates for consistency">
    Define response formats to get predictable, structured outputs.
  </Accordion>

  <Accordion title="Test template combinations">
    Variables are substituted at runtime - test with different agent configurations.
  </Accordion>

  <Accordion title="Document custom templates">
    If using custom templates, document what variables are expected.
  </Accordion>
</AccordionGroup>

***

## Related

<CardGroup cols={2}>
  <Card title="Output" icon="display" href="/concepts/output">
    Display configuration
  </Card>

  <Card title="Structured Output" icon="code" href="/features/structured">
    Pydantic output models
  </Card>
</CardGroup>