lnurl-server

A lightweight LNURL-pay / Lightning Address server that creates invoices via a NIP-47 (NWC / Nostr Wallet Connect) wallet service.

What it does

Serves /.well-known/lnurlp/<username> and /.well-known/lnurlp/<username>/callback. When a wallet requests a payment, the callback asks the NWC wallet service for a make_invoice and returns the bolt11 invoice to the payer.

Configuration (env)

• NWC_URI (required) - the nostr+walletconnect:// connection string for the

wallet service.

• LNURL_USERNAME (default me)
• LNURL_DOMAIN (default mleku.dev)
• PORT (default 8096)

Why this version

The original implementation opened a fresh WebSocket connection to the relay for every single invoice request (nostr.RelayConnect per callback), which churned TCP/TLS/WebSocket connections and leaked them into CLOSE-WAIT / FIN-WAIT-2 on the relay under load. This version:

• Keeps a single persistent relay connection, reused across requests, with

automatic reconnect if it drops.

• Serializes request/response exchanges with a mutex so concurrent callbacks

cannot cross-talk on the shared connection.

• Subscribes on the request event id (#e) so only the response to the

current request matches.

• Bounds every exchange with a timeout so a hung wallet never strands a

subscription or goroutine.

• Uses explicit HTTP server timeouts and graceful shutdown.

Build

go build -o lnurl-server .