Smart Routing
How to Enable
Smart routing is an API key-level feature, disabled by default. To use it, set the model parameter to one of the trigger values:
terminal
bash
# Any of these activate smart routing model: "auto" model: "smart" model: "anthropic/auto" model: "claude-auto"
When smart routing is not enabled (i.e., you specify a concrete model like anthropic/claude-sonnet-4-6), the request is routed exactly as specified. Smart routing never overrides explicit model selection.
Three Tiers
The scorer maps every request to one of three tiers:
| Tier | Model | Input Cost | Best For |
|---|---|---|---|
| Light | anthropic/claude-haiku-4-5 | $1.00/M tokens | Translation, summarization, classification, simple Q&A |
| Medium | anthropic/claude-sonnet-4-6 | $3.00/M tokens | Code review, technical writing, multi-step reasoning |
| Heavy | anthropic/claude-opus-4-6 | $15.00/M tokens | Complex architecture, deep analysis, agentic workflows |
The tier boundaries are based on a composite score from -1.0 to 1.0:
- Score < 0.0 -- Light tier
- Score 0.0 to 0.35 -- Medium tier
- Score > 0.35 -- Heavy tier
Next Steps
- Cost Optimization — manual strategies that complement smart routing
- Choose a Model — compare models when you prefer explicit selection
- Provider Routing — how the selected model is routed to a provider