Capability Routing and the X-Router Pattern

Modern AI systems are not single-model. They are heterogeneous: different models, different tools, different surfaces. Treating one model as the default for everything wastes capability on cheap tasks and starves expensive tasks of the right reasoning surface. ### Routing by Capability An X-Router classifies incoming work by required capability — reasoning depth, tool access, latency budget, governance class — and dispatches it to the matching surface. The router is a policy object, not a load balancer. ### Routing as Governance Because routing decisions are explicit, they are auditable. Reviewers can ask why a particular task was sent to a particular surface, and the answer is a policy, not a heuristic buried in code. Capability routing becomes part of the governance story, not an afterthought to it.