This package processes uncalibrated data for both imagers and spectrographs onboard the James Webb Space Telescope (JWST), an orbiting infrared observatory stationed at Earth-Sun L₂. It performs a series of calibration steps that result in standard data products usable for science. More information on running this pipeline, including explanations of specific stages and how to obtain reference files, can be found here.

We recommend using an isolated Python environment to install jwst.

You can create multiple environments to allow for switching between different versions of the jwst package (e.g. a released version versus the current development version).

In all cases, installing to an environment is a 3-step process:

• Create a new environment
• Activate that environment (change shell variables in the current session to point to the isolated Python installation)
• Install the desired version of the jwst package into that environment

virtualenv jwst_env/
source jwst_env/bin/activate
pip install jwst==1.20.1

pip install 'gwcs<0.22'

pip install git+https://github.com/spacetelescope/jwst

There may be occasions where an exact copy of an operational DMS build is desired (e.g. for validation testing or debugging issues in operations). We package releases for DMS builds as environment snapshots that specify the exact versions of all packages to be installed.

Note that these environment files are delivered as Conda YAMLs. To install one, you will need to have conda, mamba, or micromamba installed on your computer.

The Software vs DMS build version map, shown below, displays the jwst version for each DMS build. For example, use jwst==1.17.1 for DMS build 11.2. Also note that Linux and macOS systems require different snapshot files:

conda env create --file https://ssb.stsci.edu/stasis/releases/jwst/JWSTDP-1.18.1/delivery/latest-py312-macos-arm64.yml
conda activate JWSTDP-1.18.1-1-py312-macos-arm64

conda create -n jwstdp-1.16.0 --file https://ssb.stsci.edu/releases/jwstdp/1.16.0/conda_python_macos-stable-deps.txt
conda activate jwstdp-1.16.0
pip install -r https://ssb.stsci.edu/releases/jwstdp/1.16.0/reqs_macos-stable-deps.txt

The Calibration References Data System (CRDS) serves and manages reference files for several telescope calibration pipelines, including jwst.

The JWST CRDS server is available at https://jwst-crds.stsci.edu

Set CRDS_SERVER_URL and CRDS_PATH to run the calibration pipeline with access to reference files from CRDS:

export CRDS_SERVER_URL=https://jwst-crds.stsci.edu
export CRDS_PATH=$HOME/data/crds_cache/

The pipeline will automatically download individual reference files and cache them in the CRDS_PATH directory. Expect to use upwards of 200 gigabytes of disk space for reference files.

To use a specific CRDS context other than that automatically associated with a given pipeline version, you may also explicitly set the CRDS_CONTEXT environment variable:

export CRDS_CONTEXT=jwst_1179.pmap

Package documentation is available at https://jwst-pipeline.readthedocs.io

For more user-focused documentation, see the JDox pages at https://jwst-docs.stsci.edu/jwst-science-calibration-pipeline

We welcome contributions and feedback on the project. Please follow CONTRIBUTING.md to submit an issue or a pull request.

We strive to provide a welcoming community to all of our users by abiding with CODE_OF_CONDUCT.md

If you have questions or concerns regarding the software, please open an issue at https://github.com/spacetelescope/jwst/issues or contact the JWST Help Desk.

The table below provides information on each release of the jwst package and its relationship to software builds used in the STScI JWST DMS operations environment. The Released column gives the date on which the jwst tag was released on PyPI, and the Ops Install column gives the date on which the build incorporating that release was installed in DMS operations. Note that the CRDS_CONTEXT listed is a minimum context that can be used with that release. A release should work with any contexts between the specified context and the context specified for the next release.

See TESTING.md