Ooooh, it works!! This is a client talking to an authorization server built with the `@atproto/oauth-provider` package standalone.
I've implemented just enough to make this proof of concept work.
https://puffball.us-east.host.bsky.network/xrpc/com.atproto.sync.getBlob?did=did:plc:5w4eqcxzw5jv5qfnmzxcakfy&cid=bafkreibhwdjt4l6wb6sm2ejvdvqvv2b3baz73avpz57fstmwy352dgcngm