$ curl --fail-with-body -s -H 'Accept: application/json' 'https://atproto.brid.gy/xrpc/com.atproto.repo.listRecords?repo=did:plc:lffon5yhpjy26636i2xjl6as&collection=app.bsky.feed.post' | jq
{
"error": "InvalidRequest",
"message": "in com.atproto.repo.strongRef, string cid with value `''`: is invalid for format cid"
}