OpenAI Agents SDK
Writing the loop yourself gets old quickly: call the model, parse the tool request, run the function, append the result, call again, and somewhere in there decide when to stop. The OpenAI Agents SDK is OpenAI's own answer to that chore — a small Python (and TypeScript) library that runs the loop for you.
What it gives you
The design is deliberately thin — a handful of primitives rather than a framework to learn:
- Agents: a model, instructions, and a list of tools. Plain functions become tools from a decorator, their schema read off the type hints.
- Handoffs: one agent passes control to another — a triage agent routing to a billing specialist — which is how multi-agent work is expressed here, instead of a message bus.
- Guardrails: validation that runs alongside the agent and can halt it early on an unsafe or out-of-scope input.
- Sessions and tracing: conversation history carried across turns, and every run viewable step by step in the OpenAI dashboard.
Why it matters
It is the production successor to the experimental Swarm project, and it collapses the run-time plumbing — retries, step limits, structured output, trace spans — behind a single Runner.run() call. The trade-off is the familiar one: a lean, readable agent at the price of a loop you no longer own. Where the step cap lives, how a handoff rewrites the context the next agent sees, and what a guardrail does to an in-flight run are all worth knowing before a deployed agent surprises you.
The OpenAI Agents SDK is OpenAI's lightweight framework for building agents in Python or TypeScript. It runs the model-and-tool loop for you and exposes four primitives: agents (model plus instructions plus tools), handoffs between agents, guardrails that can stop a run, and sessions with built-in tracing. It replaced the experimental Swarm project as the supported option, so a tool-using agent ships without hand-written retries, step limits or state handling.
Getting AI software to carry out a job on its own takes a lot of repetitive wiring: ask the model what to do, do it, tell the model what happened, ask again, and know when to stop. The OpenAI Agents SDK is a ready-made kit that handles all of that wiring.
A developer writes down the assistant's job and hands it a few abilities — look up an order, send an email — and the kit takes care of the back-and-forth. It can also pass a task on to a more specialised helper, refuse requests that fall outside what it should touch, and keep a record of every step, so you can go back afterwards and see what the software did and why.