An Authored Recursive Contract Graph as the Control Plane for Coding Agents

Coding agents can produce software faster than a person can keep the result structured. Each new session tends to reconstruct architecture from source, and that reconstruction is not stable: the agent may couple the wrong units, edit across a boundary, or dissolve a module while making a local change. This note claims that the right control plane for that work is an *authored recursive contract graph*. Software is a hierarchy of encapsulation pockets. Each pocket exposes a contract: the public face the outside may use, the responsibility it owns, and the next smaller pocket to read. The graph is both the navigation structure and the encapsulation boundary, so an agent can walk the system without treating the whole repository as open interior. The claim is complementary to recovered code graphs, which show what the source currently is, and to contract-driven greenfield generation, which synthesizes a contract for one creation run. The intended setting is ongoing work on a living repository. A system called Contract Graph implements the model as schema-backed YAML nodes, task routes, and machine checks that the authored graph is closed. Correspondence between that graph and every implementation dependency is not yet proved.