trezor/blockbook ? reverse-engineered prompt

Build me a backend service for a crypto wallet that can index blockchain addresses and balances, search addresses quickly, and act like a simple blockchain explorer.

It should expose an API, websocket updates, and also work with a Bitcore Insight style REST interface so wallet apps can talk to it easily. Support Bitcoin and Ethereum style chains, and make it easy to add more coins later. Store the indexed data in a local database, and make sure it can handle a full sync of a chain without falling over.

I’d like it to be runnable on Linux, with clear setup and build instructions, and include the basic admin and developer docs needed to get a local node syncing. If anything about the current blockchain data or API behavior is unclear, look up the current docs online and match the expected behavior as closely as possible.