+ (done for most git blob retrievals, Xapian needs work)
+
+* HTTP(S) search API (likely JMAP, but GraphQL could be an option)
+ It should support git-specific prefixes (dfpre:, dfpost:, dfn:, etc)
+ as extensions. If JMAP, it should have HTTP(S) analogues to
+ various IMAP extensions.
+
+* search across multiple inboxes, or admin-definable groups of inboxes
+
+ This will require a new detached Xapian index that can be used in
+ parallel with existing per-inbox indices. Using ->add_database
+ with hundreds of shards is unusable in current Xapian as of
+ August 2020 (acknowledged by Xapian upstream).
+
+* scalability to tens/hundreds of thousands of inboxes
+
+ - pagination for WwwListing