model-switching

name	model-switching
description	Centralized model switching in sprachspiel. All model changes MUST go through switch_model() to prevent inconsistent state between think, tools, and capabilities.
license	MIT
compatibility	opencode
metadata	{"audience":"developers","workflow":"model-config"}

What I do

I enforce the SINGLE POINT OF FAILURE rule for model switching in sprachspiel. All model changes MUST go through the centralized switch_model() function.

When to use me

Use this skill when implementing model switching functionality, modifying the /model command, or any code that changes the active LLM model.

The Rule

CRITICAL: All model switching MUST go through src/chat/model_switch.rs.

The switch_model() function is the ONLY place that handles:

• Model validation
• Config resolution
• Capability detection
• Think/tools state adjustment
• Warning generation

Correct Usage

// ✅ CORRECT - Use the centralized function
match super::model_switch::switch_model(
    name,
    &ollama,
    &capabilities,
    session.think,
    session.tools,
).await {
    Ok(result) => {
        session.set_model(result.model_name.clone());
        session.think = result.think_active;
        session.tools = result.tools_active;
        // ... update other state
    }
    Err(e) => eprintln!("{}", e),
}

What NEVER to Do

// ❌ WRONG - Never duplicate this logic
if !user_models::is_model_valid(name) { ... }
let config = user_models::resolve_model_config(name);
let caps = ModelCapabilities::detect(...).await;
// ... etc

Why this matters:

• Prevents inconsistent state between session.think, session.tools, and tools_active
• Ensures capabilities are always detected and warnings are consistent
• Single place to fix bugs related to model switching

Related Code Paths

File	What it does
src/chat/model_switch.rs	Central switch_model() function
src/chat/custom_coordinator.rs	Model passed to coordinator
src/capabilities.rs	ModelCapabilities::detect_or_default()
src/user_models.rs	Model validation and config resolution
src/chat/session.rs	ChatSession::set_model()

Common Patterns to Use Instead of Duplicating

1. Model configuration building — Use ModelConfig::build_model_options()
2. Capability detection — Use ModelCapabilities::detect_or_default()
3. Thinking display — Use display_thinking()
4. Model resolution — Use resolve_model_config()
5. Think mode validation — Use resolve_think_mode()
6. Model switching — Use model_switch::switch_model() (this skill)