Umbra JSON-RPC endpoint

This is an API, not a web page. Send an authenticated POST (HTTP Basic auth).

curl -u dev:a79e2dd2756e96f5 \
  --data-binary '{"method":"getblockchaininfo","params":[]}' \
  -H 'content-type:text/plain' https://rpc.getumbra.org/

Allowed: block/tx/address reads, mempool, sendrawtransaction, and Umbra methods (protx, getmixdir, getshardnodes, quorum, masternode). Blocked: wallet/admin methods (stop, setban, generate*).