API Reference

This API reference is automatically generated from Prefect's source code and unit-tested to ensure it's up to date.

Hello, world! 👋

We've rebuilt data engineering for the data science era.

Prefect is a new workflow management system, designed for modern infrastructure and powered by the open-source Prefect Core workflow engine. Users organize Tasks into Flows, and Prefect takes care of the rest.

Read the docs; get the code; ask us anything!

from prefect import task, Flow

def say_hello():
    print("Hello, world!")

with Flow("My First Flow") as flow:

flow.run() # "Hello, world!"


Prefect's documentation -- including concepts, tutorials, and a full API reference -- is always available at docs.prefect.io.


Read about Prefect's community or dive in to the development guides for information about contributions, documentation, code style, and testing.

Prefect is committed to ensuring a positive environment. All interactions are governed by our Code of Conduct.


From the Latin praefectus, meaning "one who is in charge", a prefect is an official who oversees a domain and makes sure that the rules are followed. Similarly, Prefect is responsible for making sure that workflows execute properly.

It also happens to be the name of a roving researcher for that wholly remarkable book, The Hitchhiker's Guide to the Galaxy.



Prefect requires Python 3.5+.

Install latest release

Using pip:

pip install prefect

or conda:

conda install -c conda-forge prefect

Install bleeding edge

git clone https://github.com/PrefectHQ/prefect.git
pip install ./prefect


Prefect is licensed under the Apache Software License version 2.0.

This documentation was auto-generated from commit n/a
by Prefect 0.5.3+275.g38ab4505 on May 28, 2019 at 20:38 UTC