KNN

Overview

knn is a selection algorithm for nearest-neighbor model selection.

It aligns to config/algorithm/selection/knn.yaml.

Key Advantages

• Makes example-based routing explicit in config.
• Keeps the route-level policy compact.
• Works well when similar prompts should choose similar models.

What Problem Does It Solve?

Some routing policies are easier to express as “pick the model that worked for similar prompts.” knn exposes that nearest-neighbor selector directly in the decision.

When to Use

• you have historical prompt-to-model examples
• similar prompts should usually map to the same candidate model
• the route should use retrieval-style selection instead of fixed ranking

Configuration

Use this fragment inside routing.decisions[].algorithm:

algorithm:
  type: knn