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It relies on http. WebSocket is not typically deployed for Steem these days and I don't think it ever will be for Hive. Although, if you really want to, you could deploy lineman to provide WebSocket for apps that need it.

Meeseeker could indeed reduce RPC load, but the main goal is to benefit app developers who may run many services.

It's might even be possible to index the entire blockchain. A more reasonable solution, in that regard, would be if an exchange captured every op, but then only marked transfers they cared about, so they would never expire. Then, they could easily look up a transfer by trx_id.