PRAGMA index_xinfo(table) DOES return that data:

(Pdb) [c[0] for c in fresh_db.execute("PRAGMA > index_xinfo('idx_dogs_age_name')").description]
['seqno', 'cid', 'name', 'desc', 'coll', 'key']
(Pdb) fresh_db.execute("PRAGMA index_xinfo('idx_dogs_age_name')").fetchall()
[(0, 2, 'age', 1, 'BINARY', 1), (1, 0, 'name', 0, 'BINARY', 1), (2, -1, None, 0, 'BINARY', 0)]

See https://sqlite.org/pragma.html#pragma_index_xinfo

Example output: https://covid-19.datasettes.com/covid?sql=select+*+from+pragma_index_xinfo%28%27idx_ny_times_us_counties_date%27%29
Originally posted by @simonw in #260 (comment)