Fulcrum C++ Electrum-protocol server. Faster than electrs for query throughput, at higher RAM cost. Repo: . Setup Bitcoin Core with . Then Fulcrum: Indexes 1-2 days; 10-15 GB additional disk. When to choose Fulcrum - High-traffic public Electrum server. - Power users with multiple wallets connecting. - BTCPay backend with many invoices. When to choose electrs - Personal use, low traffic. - Resource-constrained devices. - Simpler config preferred. Compatibility Same as electrs — Sparrow, Electrum, BTCPay, etc. Common bugs - High RAM usage (8+ GB) → tune , . - TLS cert mismatch on SSL endpoint…