PromptL Syntax Guide

Comprehensive guide for writing PromptL prompts in the Latitude platform. PromptL is a versatile, human-readable language that simplifies defining and managing dynamic prompts for LLMs.

When to Apply

Reference these guidelines when:

• Writing new PromptL prompts for Latitude
• Configuring LLM models and parameters
• Using variables, conditionals, or loops in prompts
• Creating multi-step chains or agentic workflows
• Defining tools for function calling
• Referencing other prompts (snippets)
• Working with structured JSON output schemas

Syntax Categories

Category	Purpose	Key Syntax
Configuration	Define model, provider, and parameters	--- YAML block
Messages	Structure conversations	<system>, <user>, <assistant>, <tool>
Variables	Dynamic content	{{ variable }}
Conditionals	Dynamic flow control	{{ if }}, {{ else }}, {{ endif }}
Loops	Iterate over lists	{{ for item in list }}, {{ endfor }}
Chains	Multi-step prompts	<step>
Tools	Function calling	tools: in config
Agents	Autonomous workflows	type: agent
Snippets	Reusable prompts	<prompt path="..." />
Content	Multi-modal content	<content-image>, <content-file>

Quick Reference

Configuration Block

---
provider: OpenAI
model: gpt-4o
temperature: 0.7
top_p: 0.9
maxSteps: 20
---

Message Tags

• <system> - System instructions
• <user> - User messages
• <assistant> - Assistant responses
• <tool> - Tool interaction results
• <message role="..."> - Generic message tag

Variables

{{ variable_name }}
{{ variable || "default" }}
{{ set myVar = "value" }}

Conditionals

{{ if condition }}
  content
{{ else }}
  alternative
{{ endif }}

Loops

{{ for item, index in items }}
  {{ index }}: {{ item }}
{{ else }}
  No items
{{ endfor }}

Chains (Multi-step)

<step as="result">
  First step content
</step>

<step>
  Use {{ result }} from previous step
</step>

Tools Configuration

tools:
  - tool_name:
      description: What the tool does
      parameters:
        type: object
        properties:
          param_name:
            type: string
            description: Parameter description
        required:
          - param_name

Agents

---
type: agent
provider: OpenAI
model: gpt-4o
tools:
  - latitude/search
agents:
  - agents/sub-agent-path
maxSteps: 40
---

Structured Output

schema:
  type: object
  properties:
    field_name:
      type: string
      description: Field description
  required:
    - field_name

Prompt References (Snippets)

<prompt path="relative/path/to/prompt" />
<prompt path="shared/policies" variable={{ value }} />

Content Types

<content-text>Plain text</content-text>
<content-image>{{ image_url }}</content-image>
<content-file mime="application/pdf">{{ file_data }}</content-file>

How to Use

Read the AGENTS.md file for the complete detailed guide with all syntax explanations, examples, and best practices.

Each section contains:

• Detailed explanation of the feature
• Correct usage examples
• Common mistakes to avoid
• Best practices and tips