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pymmcore-plus aims to extend pymmcore (python bindings for the C++ micro-manager core) with a number of features designed to facilitate working with Micro-manager in pure python/C environments.

  • pymmcore-plus itself is a superset of pymmcore (python bindings for Micro-manager's C++ CMMCore). pymmcore_plus.CMMCorePlus (the main object in this library) aims to be a drop-in replacement for pymmcore.CMMCore, while adding a number of additional features including:

    • A multi-dimensional acquisition engine implemented in pure python. (The existing acquisition engines in Micro-manager are written in Java and Clojure).
    • More flexible event connections and callback handling.
    • Extended convenience APIs for working with core (which would be hard or impossible to implement in the pymmcore SWIG wrapper).
    • More pythonic APIs for various pymmcore objects (e.g. pymmcore_plus.Device, pymmcore_plus.Configuration) and constants.
  • pymmcore-widgets is a Qt-based widget library built on pymmcore-plus that provides GUI elements for most of the device and acquisition functionality of pymmcore. It allows users to build their own custom GUIs for Micro-manager.

  • napari-micromanager is a plugin for the napari image viewer that composes pymmcore-plus and pymmcore-widgets to provide a full GUI for Micro-manager that is integrated with the napari viewer.

How is pymmcore-plus different than Pycro-Manager?

A common question about pymmcore-plus and related libraries is how it differs from Pycro-Manager, another python library written by Henry Pinkard for working with Micro-manager.

The two projects are not mutually exclusive! They aim to support different use cases

The primary difference is that Pycro-Manager controls Micro-manager via a ZMQ-based connection to a remote Java process in which the Micro-manager GUI is running (or a headless Java process if the GUI is not running). The Java process in turn communicates with the C++ core driving the hardware.

pymmcore-plus aims to remove the need for a Java process by communicating directly with the C++ core (via the pymmcore library), and re-implementing any necessary event-based or GUI-based functionality in pure python or C.

A major advantage of Pycro-Manager is that you get the entire Java-based micro-manager ecosystem, including the GUI and plugins. A potential disadvantage (depending on your needs), is that it requires a Java runtime environment and cross-process communication.

If you are looking to control a microscope via python without any need for Java or interprocess communication, pymmcore(-plus) may help. Note however, that you will be sacrificing the MMStudio GUI! See pymmcore-widgets and napari-micromanager for ongoing efforts to re-implement GUI components in python.

micro-manager ecosystem components



Install with pip or conda:

pip install pymmcore-plus

# OR, to include the `mmcore` command line tool
pip install "pymmcore-plus[cli]"

# OR
conda install -c conda-forge pymmcore-plus

You will also need the micro-manager device adapters on your system. To get them quickly, assuming you have installed with pymmcore-plus[cli], you can run:

mmcore install

See install for more details.


The main object is pymmcore_plus.CMMCorePlus, which is an enhanced subclass of pymmcore.CMMCore:

from pymmcore_plus import CMMCorePlus

# instantiate as you would pymmcore.CMMCore
mmc = CMMCorePlus()
# OR: use the global singleton
# mmc = CMMCorePlus.instance()

# without arguments, this will load the demo config

See the CMMCorePlus API documentation for details on the additional features of CMMCorePlus.


Creating/accessing a CMMCorePlus object using CMMCorePlus.instance() is a convenient way to access the same core instance from multiple places in your code. All widgets in pymmcore-widgets also use CMMCorePlus.instance() by default, so any widgets you use will automatically connect to the same core instance without any additional configuration.

Attempts are made to make it thread-safe. But please open an issue if you find any problems.

While you can easily use pymmcore-plus from a script or IPython/Jupyter you can also use it in combination with the napari based gui napari-micromanager. See using with napari-micromanager for an example of how to use them together.


We welcome contributions to pymmcore-plus and related libraries. Please see contributing for more information.