Implicit Installation

CRDS is installed implicitly with the conda installation of HST or JWST calibration software.

To check for CRDS try:

$ crds list --version
7.0.5, master, c95d1cc

If CRDS is not already installed, it can be installed using in a variety of mechanisms including AstroConda contrib, PyPi, and GitHub source code.

Installation via AstroConda

One way to install CRDS directly is as an AstroConda contributed package:

  1. Install Continuum’s Anaconda or Miniconda

Installing Anaconda gives you a generic environment for numerical programming. See:

for Anaconda installation instructions.

  1. Set up AstroConda astronomy specific packages

AstroConda is a collaborative effort producing astronomy related packages and making them available for installation via Conda.

Nominally, setting up AstroConda is something like:

$ conda config --add channels
$ conda create -n astroconda stsci
$ source activate astroconda

Pip Installation

It’s also possible to install and update CRDS using PyPi system like this:

$ pip install crds

Installing CRDS via Conda is preferred.

Installing from Source

CRDS source code can be cloned from the GitHub source code repository as follows:

$ git clone CRDS
$ cd CRDS

$ # optionally,  switch to release tag
$ git fetch origin
$ git checkout <release tag,  e.g. 6.0.1>

Run the ./install script in the root source code directory to install from source code:

$ cd CRDS
$ ./install
final status 000000


CRDS was developed in and for an STSCI Python environment suitable for pipeline processing. Standard STScI calibration environments should already include it. Nevertheless, for installing CRDS independently, these dependencies are applicable:

REQUIRED: CRDS requires these dependencies to be installed in your Python environment:
  • numpy
  • astropy

OPTIONAL: Additional 3rd party supporting packages are needed for more advanced CRDS functions:

Optional Supporting Packages
Package Supports Task
jwst to run crds certify for JWST
firelock for lock file based CRDS cache locking for multiprocessing (preferred)
lockfile for lock file based CRDS cache locking for multiprocessing (deprecated)
fitsverify for running fitsverify under certify
lxml for command line submission interface
requests for command line submission interface
Parsley-1.3 for certifying CRDS rules files
pyaml for certifying and using yaml references
asdf for certifying and using ASDF references
docutils for building documentation
sphinx for building documentation
stsci.sphinxext for building documentation
nose for running CRDS unit tests