Sign Planetary Computer STAC items, caching the token per collection.

Microsoft Planetary Computer assets need a SAS token appended to each asset href before they can be read. Unlike rstac::items_sign(), which requests a token on every call and can storm the MPC signing endpoint into 429s when signing many items, stac_sign_mpc() caches the collection-level token in memory AND on disk (under tools::R_user_dir()) and reuses it until it expires (msft:expiry) – one request per collection instead of one per item. Use it in place of rstac::items_sign() after stac_query().

Usage

stac_sign_mpc(items, subscription_key = Sys.getenv("MPC_TOKEN", unset = NA))

Arguments

items

An rstac doc_items from stac_query().

subscription_key

Optional MPC subscription key (defaults to the MPC_TOKEN environment variable). Not required for public data.

Value

items with every asset href signed.

See also

Other stac helpers: lazy_stac_stack(), stac_drop_duplicates(), stac_filter_assets(), stac_filter_cloud(), stac_filter_coverage(), stac_filter_orbit(), stac_gti_index(), stac_merge(), stac_query(), stac_rename_assets(), stac_sources(), stac_time_slices()