November 10, 2022

About This Article

As of November 10, 2022, all observers should use the standard CRDS OPS server ( for obtaining the best JWST calibration reference files.

The alternate PUB server ( will be decommissioned. This server was set up in anticipation of rapid reference file updates during commissioning and Cycle 1. However, following the smooth transition to science operations — and to avoid confusion — it has been decided that the PUB server is no longer needed. To make this transition as smooth as possible, this change will take place in stages.

On November 10, all observers should begin to transition to using only the CRDS OPS server, and the PUB server will be frozen. See the software documentation for instructions about how to configure CRDS.

In early December, access to the PUB server will no longer be available externally. On March 1, the PUB server will be fully decommissioned and STScI will retain an internal archive of the maps and calibration reference files. Observers who wish to use historical files from the PUB server in the future may file a JWST Help Desk ticket to access the information.

Part of the decommissioning process will include establishing guidance for how best to maintain reproducibility for new papers and for already-published papers that used the PUB server. This information will be included in a future JDox page: How to Cite Your Data Reduction and Reference Files.


This site is protected by reCAPTCHA and the Google

Webb Space Telescope insignia


For technical assistance, please contact the JWST Help Desk.


The NASA James Webb Space Telescope, developed in partnership with ESA and CSA, is operated by AURA’s Space Telescope Science Institute.