Japanese version: IModelVectorRouter (インターフェース仕様)

IModelVectorRouter (Interface Specification)

1. Responsibility Boundary

IModelVectorRouter is the routing boundary interface that selects an optimal model/provider based on required capability vectors and execution constraints.

• Role:

Perform multi-dimensional capability matching, apply rule/constraint-based filtering, and produce deterministic final routing decisions.

• Non-role:

Actual inference execution belongs to the selected implementation. Capability registration and lifecycle management belong to ICapabilityRegistry.

2. Contract Signature

namespace AIKernel.Abstractions.Routing;\n\nusing AIKernel.Abstractions.Models;\n\npublic interface IModelVectorRouter\n{\n    Task<ModelRoutingDecision> RouteAsync(\n        ModelCapacityVector requiredCapacity,\n        RuleEvaluationContext ruleEvaluationContext,\n        IExecutionConstraints executionConstraints,\n        CancellationToken cancellationToken = default);\n\n    ModelType SelectOptimalModel(ModelCapacityVector requirement, IEnumerable<ModelType> candidates);\n\n    IEnumerable<(ModelType Model, float Score)> RankModels(\n        ModelCapacityVector requirement,\n        IEnumerable<ModelType> candidates);\n\n    bool VerifyDeterministicRouting(ModelRoutingDecision decision1, ModelRoutingDecision decision2);\n}

3. Related Use Cases

• UC-03 Model vector routing:

Core path for selecting execution units from requirement vectors.

• UC-22 Dynamic capacity control and model routing:

Optimizes routing under changing budget, load, and capability conditions.

• UC-30 Token/vector estimation:

Evaluates executability against estimated task vectors.

4. Governance & Determinism

• Deterministic routing:

Identical capability requirements, rule context, and execution constraints must yield identical ModelRoutingDecision outputs.

• Fail-Closed:

If no candidate satisfies mandatory capabilities, the implementation must terminate as deny/failure rather than silently degrading to a weaker route.

5. Exception Contract

This interface does not hard-code specific exception types. Implementations should explicitly handle:

• No viable route:

No candidates exist, or all candidates are excluded by constraints.

• Constraint violations:

IExecutionConstraints (budget, region, latency, etc.) makes execution impossible.

6. Implementation Notes

• Multi-axis evaluation:

Evaluate multiple ModelCapacityVector axes in an explainable way instead of collapsing everything into a single opaque metric.

• Auditability:

Keep routing rationale (scores, exclusion reasons, tie-break basis) traceable in ModelRoutingDecision.

Changelog

• v0.0.0 / v0.0.0.0: Initial draft
• v0.0.1 (2026-05-06): Version upgrade aligned with documentation guidelines