Define and run Agents through atomic APIs with full control over the runtime — no need to build your own agent loop or sandbox.
Build Mode provides fully managed Agent definition and execution as an atomic layer. Use the API to define an Agent, start a Session, and dynamically mount the resources it needs — sandbox environments, Skills, files — then receive results in real time via event streaming. You do not need to build your own agent loop or tool-execution sandbox.
Each call decides which resources to mount, giving you fine-grained control over the Agent's runtime behavior. Build Mode is designed for teams that want full ownership of the product logic on top of the Agent runtime. This layer contains the resource families: Common Conventions, Agents, Sessions, Deployments, and Dreams.