Hello World

The smallest complete Flux program — one task, one workflow.

The smallest complete Flux program: a single @task called from a single @workflow. Start here to see the shape every Flux program shares — tasks do the work, the workflow orchestrates them, and ExecutionContext carries the input. Reach for this pattern when you want a runnable baseline before adding retries, parallelism, or persistence.

Run it

python examples/hello_world.py

from __future__ import annotations

from flux import ExecutionContext
from flux.task import task
from flux.workflow import workflow


@task
async def say_hello(name: str):
    return f"Hello, {name}"


@workflow
async def hello_world(ctx: ExecutionContext[str]):
    if not ctx.input:
        raise TypeError("Input not provided")
    return await say_hello(ctx.input)


if __name__ == "__main__":  # pragma: no cover
    ctx = hello_world.run("Joe")
    print(ctx.to_json())