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Build a Fractal task

Fractal tasks are the core processing units of to build your workflows. Each Fractal task loads the data from one (or many) OME-Zarr(s) and applies processing to them. Fractal tasks are Linux command line executables. For the purpose of this demo, we will look at the Python implementation. You can think of a Fractal task as a Python function that knows how to process an OME-Zarr image and save the results back into that OME-Zarr image. With a bit of syntax sugar, this becomes a Fractal task you can then run from the web interface. To understand the types of tasks, their API & how they provide information to Fractal server, check out the V2 Tasks page.

This page is all about building your own Fractal task. It comes down to 5 steps:

  1. Create a repository for your tasks using the fractal-tasks-template.

  2. Develop your Python function to process an OME-Zarr as desired & follow the Fractal API for task input & function outputs.

  3. Update the task-list to generate a Fractal manifest in your package.

  4. Package your task (locally or via pypi).

  5. Install your task on a given Fractal server.

This video walks you through all those steps for how to implement a custom Fractal task that does image-labeling based on a user-defined threshold.


If you prefer to follow a written guide, follow the instructions in the README of fractal-tasks-template.