Variants

Variants are specialized model configurations that inherit from Base Providers. They allow you to create reusable configurations with custom system prompts (e.g., for different personalities), temperature settings, and other parameters tailored for specific tasks.

What Are Variants?

Instead of specifying provider settings in each prompt, variants let you:

• Define once, use everywhere: Create specialized configs like rust-coder, quick-responder, or formal-writer
• Override settings: Change temperature, cache_ttl, ..etc
• Simplify prompts: Reference by name instead of full provider/model paths
• Maintain consistency: Ensure the same settings across related prompts

Creating Variants

Variants are defined in your config.toml as subsections of providers:

[providers.{provider}.{variant-name}]

Basic Variant

[providers.anthropic.quick]
system = "Be extremely brief and direct."
temperature = 0.3
max_tokens = 500

Usage in prompts:

---
model: quick  # Instead of anthropic/claude-sonnet-4
---
{{STDIN}}

You can create as many variants per base provider as you need.

Variant Configuration Options

All provider settings can be overridden in variants:

[providers.anthropic.my-variant]
system = "Custom system prompt"
temperature = 0.7
max_tokens = 2000
cache_ttl = 60

Using Variants in Prompts

Reference variants by name in your prompt frontmatter:

---
model: rust-coder
---
Generate a Rust function that {{STDIN}}

This is equivalent to but much simpler than:

---
model: anthropic/claude-sonnet-4
temperature: 0.2
max_tokens: 3000
system: |
  Rust coding assistant.
  Follow Rust idioms and best practices...
---
Generate a Rust function that {{STDIN}}