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

promptl

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