Decisions

Overview

Signals tell the Router what it detected. Decisions turn those detections into a route policy:

• which route matched
• which models are candidates
• whether reasoning is enabled
• which plugins run after the route is chosen

Key Advantages

• Keeps route policy readable even when multiple signals must cooperate.
• Makes boolean logic explicit and reviewable.
• Separates route matching from deployment bindings, algorithms, and plugins.

What Problem Does It Solve?

Without a decision layer, signal outputs do not tell the router how to react. Teams end up scattering route logic across ad hoc if-statements, model defaults, and plugin wiring.

Decisions solve that by turning named signals into clear route policies with stable priorities and candidate models.

When to Use

Use a decision when:

• a route should activate from one or more signals
• the same model policy should be reused across several signal combinations
• route priority matters
• plugins or algorithms should attach to a matched route instead of the whole router

Configuration

In v0.3, decisions live under routing.decisions:

routing:
  decisions:
    - name: business_route
      description: Route business requests to the business model.
      priority: 110
      rules:
        operator: AND
        conditions:
          - type: domain
            name: business
      modelRefs:
        - model: qwen2.5:3b
          use_reasoning: false

Decision matching stays separate from:

• providers.models[], which carries deployment bindings
• decision.algorithm, which chooses among multiple candidate models
• decision.plugins, which post-processes a matched route

Choose the smallest shape that expresses the policy clearly:

Decision shape	Best for	Guide
Single condition	One decisive signal	Single Condition
AND	Several conditions that must all match	AND Decisions
OR	One route shared by several alternative conditions	OR Decisions
NOT	An explicit exclusion or safety guard	NOT Decisions
Composite	Nested combinations of AND, OR, and NOT	Composite Decisions
Retention directives	Cache or session side effects after a decision matches	Retention Directives

Add Algorithm when modelRefs contains more than one candidate, and add Plugin when the route needs post-selection behavior.

Operational Boundaries

• Every leaf must reference a signal or projection output declared in the same recipe.
• Higher priority wins when more than one decision matches. Keep an explicit unconditional fallback or configure providers.defaults.default_model.
• Decision names and route diagnostics can become operational metadata; avoid secrets or personal identifiers in names and descriptions.
• Boolean logic is policy, not authentication. Use trusted identity through the authz service and signal for access-sensitive routes.