A Python function

What is supported

Any Python 3.11 or 3.12 code. A function is what Onecortex calls when the object is not a framework it recognises, so it is also how you deploy an agent on a framework not listed here, such as AutoGen or Pydantic AI: wrap its run call.

A complete agent

agent.yml

apiVersion: v1
runtime: python3.12
entrypoint: agent.py:agent
dependencies: requirements.txt

requirements.txt

# No dependencies. List any you add here.

agent.py

def agent(prompt: str) -> str:
    return f"You said: {prompt}"

Call any model you like from inside the function, with its key added as a secret on the agent’s Config tab. See Configuration and secrets.

A complete A Python function example

echo: The quickstart’s agent: one tool call of its own, then a reply, with no dependencies.

The prompt and the reply

The function receives the prompt. What it may be:

Shape	Reply
`def agent(prompt)` returning a string	The string, once
A generator, `yield` strings	Each string as it is yielded
`async def`, returning a string	The string, once
An async generator	Each string as it is yielded
A callable class instance, or an object with `invoke(prompt)`	As above, by what it returns

Declare a second positional parameter to receive the session ID: def agent(prompt, session_id). Declare a parameter named request to receive the whole request: {"prompt", "sessionId", "params", "surface", "messages"}.

Events it reports

Events	From
`text`	Each string you return or yield
Any event	Yield a dict with a `type`, and it is sent as that event, checked first
`done` or `error`	The end of the run: always exactly one

See Streaming and events.

The caller’s fields

In request["params"], for a function that declares request:

def agent(prompt: str, request: dict) -> str:
    model = request["params"].get("model", "gpt-5")
    return call_my_model(model, prompt)

Report tool calls and steps

Yield event dicts alongside your text, and they reach every caller as real events:

import json


def agent(prompt: str):
    yield {"type": "tool_call_start", "id": "call_1", "name": "word_count"}
    yield {"type": "tool_call_args", "id": "call_1", "delta": json.dumps({"text": prompt})}
    yield {"type": "tool_call_end", "id": "call_1"}
    yield {"type": "tool_result", "id": "call_1", "output": str(len(prompt.split()))}
    yield f"You said: {prompt}"

Each dict needs the fields of its event type. v is filled in for you, and Onecortex adds the closing done. A dict that is not a valid event ends the run with Your agent yielded an event Onecortex cannot read: and the field that is wrong.

Known limits

A dict with a type key is always read as an event. Yield a string, or JSON text, to send data that has a type field.

Troubleshooting

You see	Do this
`Your agent yielded an event Onecortex cannot read: <problem>.`	Fix the field it names. Every event’s fields are on Streaming and events.

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What is supported

A complete agent

A complete A Python function example

The prompt and the reply

Events it reports

The caller’s fields

Report tool calls and steps

Known limits

Troubleshooting

​What is supported

​A complete agent

A complete A Python function example

​The prompt and the reply

​Events it reports

​The caller’s fields

​Report tool calls and steps

​Known limits

​Troubleshooting

What is supported

A complete agent

The prompt and the reply

Events it reports

The caller’s fields

Report tool calls and steps

Known limits

Troubleshooting