<Token var=<ContextVar name=‘current_thread’      │
│           default=None at 0x10c9bb010> at 0x12249dd00> was created in a different Context

with marvin.Thread() as thread:

current_thread

marvin.extract

async def

await marvin.extract_async(...)

from marvin import extract_async

    async def parse_invoice(text: str):
        # Give the inner call its own Marvin thread name to avoid relying on a ContextVar
        return await extract_async(
            data=text,
            target=InvoiceModel,
            thread="tool:parse-invoice"
        )

current_thread

from marvin import extract

    def parse_invoice(text: str):
        return extract(
            data=text,
            target=InvoiceModel,
            thread="tool:parse-invoice"  # any stable string ID works
        )

pip install -U marvin

"""
Reproduce context error when calling marvin.extract within a tool that is called by an agent.
Error: "Token var=<ContextVar name='current_thread' default=None> was created in a different Context"
"""

from pydantic import BaseModel

import marvin


class ExtractedInfo(BaseModel):
    name: str
    age: int | None = None


def extract_info_from_text(text: str) -> str:
    """Extract structured information from text using marvin.extract."""
    # This should trigger the context error when called by an agent
    extracted = marvin.extract(
        data=text,
        target=ExtractedInfo,
        instructions="Extract name and age from the text",
    )
    return f"Extracted: {extracted}"


def main():
    # Create an agent with the extract tool
    agent = marvin.Agent(
        name="ExtractorAgent",
        tools=[extract_info_from_text],
        instructions="You are a helpful assistant that extracts information from text.",
    )

    # Try to use the agent to call the tool
    result = agent.run("Please extract info from this text: 'John is 25 years old'")
    print(f"Result: {result}")


if __name__ == "__main__":
    main()

marvin.Team