The OpenAI Agents SDK, from the inside out.

The video is generated as a deterministic HTML composition in HyperFrames. It mirrors this guide’s architecture language and uses nine measured narration chapters as the timing authority.

The Responses API is the model-facing substrate. The SDK’s default model adapter speaks that API, while Runner provides the client-side control loop and the rest of the package supplies reusable application and production primitives.

Every entry point—async, synchronous, or streamed—feeds the same core state machine. Final output ends a run; tool calls and handoffs create another turn.

The SDK remains approachable because most developers begin with Agent, a tool, and Runner. Additional surfaces appear as the workflow takes on production responsibilities.

A manager calls specialists as tools and keeps authority. A handoff changes the active agent and conversation owner. The difference affects policy, context, latency and evaluation—not just code organization.

Memory, safety and approvals are separate concerns. The architecture is strongest when the team chooses each intentionally rather than treating “agent state” as one undifferentiated blob.

Tracing is a debugging interface and a product feedback loop. Usage turns architectural choices—more agents, more tools, longer histories—into measurable cost and latency.

Strong PM answers connect developer friction, design principles, metrics and tensions. Avoid a feature-tour answer; explain why the runtime boundary exists and what good product outcomes look like.