Command line recipes

For complete option details, see the command reference.

Viewing MAST metadata columns

List metadata for all available MAST observation columns:

mastodown get-meta

Querying products

Query JWST products and save the resulting table to CSV:

mastodown query --programs 01200 02473 --calib-level 1 --product-type SCIENCE --extension fits -o products.csv

Filter options accept one or more space-separated values. Use --keep-ta to retain target-acquisition observations and --verbose to print observation details. Use --filters for MAST instrument filters, --date-range START_DATE END_DATE for inclusive YYYY-MM-DD observation dates, and --max-entries to limit returned observations.

Downloading products

Query products and download them after confirmation:

mastodown download --programs 01200 02473 --download-dir data --dry-run

The download command prompts after showing the query result; press Enter to continue, enter n to cancel, or pass -y / --yes to skip the prompt. Use --query-output products.csv to save the query result, and --no-proposal-subdir to save files directly in the download directory. Use --target-subdir to place each product under its target name, after the optional proposal directory.

Accessing proprietary data without an environment variable

As described in the installation docs, the simplest way to access proprietary data is by storing your MAST API token in an environment variable.

Alternatively, you can pass --auth to securely enter a token through Astroquery’s prompt:

mastodown query --programs 01200 --auth

The environment token takes precedence over --auth. Do not pass tokens directly on the command line.