Python SDK
Courier SDK
Our programmatic agent building SDK. Configure OpenAI compatible agents or contact us to license our engine for running local agents in your distributed Mac app.
Write once. Run either place.
You should not rewrite an agent because the model moved from a token API to a Mac on your desk. Courier SDK is the same Model, Agent, and Operator — two runtimes.
from courier_os import Model, Agent, Operator
Same Python. Two runtimes.
API mode
Point at Courier Cloud, OpenAI, or any OpenAI-compatible base URL. No binary, no license — an API key.
pip install courier-os
Local mode
Load an MLX model on Apple Silicon you own. Same agent code. Unlimited usage, air-gapped.
Contact for License
What ships in the package
Python agents you can actually ship: tools, a tool loop, a session that can grow mid-run, and a one-shot relay.
Model, Agent, Operator
Agent is one model turn — you handle tool_calls. Operator runs the loop until the model finishes.
@tools.tool
Typed tools you own. Decorate a function; the SDK ships the OpenAI tool schema.
Session + mid-loop register
Pass a Session and tools=session.tools, then event.register_tool from an intercept. New tools hit the next Operator iteration.
relay()
One-shot HTTP path: model, messages, tools, api_key, base_url. Same surface as Agent without the object graph.
Multimodal
OpenAI-shaped image and audio content parts on both paths. Local omni models extract media before inference.
courier-os[local]
Optional courier-os-binary on Apple Silicon. Same Model, Agent, and Operator — air-gapped MLX.
# pip install courier-os # or contact for local inference license # Apple Silicon from courier_os import Model, Agent, Operator, tools @tools.tool def get_weather(city: str) -> dict: return {"city": city, "temp_f": 72} model = Model("gpt-4o", api_key="…", base_url="https://api.openai.com/v1") # model = Model("mlx-community/…", mode="local") agent = Agent(model, tools=[get_weather]) out = Operator(agent).run([{"role": "user", "content": "Weather in Denver?"}]) print(out.content)
Full README, dual-mode table, Session intercepts, and multimodal examples on PyPI.