feat: Namecoin NIP-05 identity resolution

[mstrofnone]

Namecoin NIP-05 Identity Resolution

This PR adds decentralised NIP-05-style identity verification using Namecoin blockchain names, enabling Nostr identity lookups without relying on centralised HTTP servers.

What is Namecoin?

Namecoin is the first fork of Bitcoin (2011) — a decentralised naming blockchain. Names in the d/ (domain) and id/ (identity) namespaces can store arbitrary JSON values, including Nostr public keys. This enables trustless, censorship-resistant identity verification.

Architecture

Browser  →  HTTP Proxy  →  ElectrumX  →  Namecoin Blockchain
(fetch)     (Node.js)      (TCP/TLS)     (SPV verification)

Browsers cannot open raw TCP/TLS connections to ElectrumX servers, so an HTTP proxy bridges the gap. Three proxy options are included:

• Vite plugin (vite-plugin-namecoin.mjs) — zero-config dev middleware at /__namecoin
• Standalone proxy (electrumx-proxy.mjs) — production HTTP server
• ElectrumX client (electrumx-client.mjs) — reusable Node.js TCP client

The ElectrumX protocol flow:

1. Build canonical name-index script (OP_NAME_UPDATE + name)
2. Compute scripthash (SHA-256, byte-reversed)
3. blockchain.scripthash.get_history → get latest transaction
4. blockchain.transaction.get → parse NAME_UPDATE script for JSON value
5. Check expiry (names expire after 36,000 blocks without renewal)

Supported Identifier Formats

Format	Resolves to
alice@example.bit	d/example → names.alice
_@example.bit / example.bit	d/example → root identity
d/example	Direct domain namespace lookup
id/alice	Direct identity namespace lookup

Namecoin Value Formats

Domain namespace (d/) — NIP-05-compatible:

{ "nostr": { "names": { "alice": "<hex-pubkey>" }, "relays": { "<hex-pubkey>": ["wss://..."] } } }

Identity namespace (id/):

{ "nostr": { "pubkey": "<hex-pubkey>", "relays": ["wss://..."] } }

Both also support the simple form: { "nostr": "<hex-pubkey>" }

Integration

The resolver hooks into the existing getNip05For() function in nip05.ts. When an identifier is detected as Namecoin (.bit suffix, d/, or id/ prefix), it routes to the decentralised resolver instead of the standard HTTPS fetch path. The return type is the same ProfilePointer, so all downstream code works unchanged.

Includes an LRU cache (500 entries, 1hr TTL) to minimise ElectrumX round-trips.

Tests

21 unit tests covering identifier detection, parsing, and value extraction for all supported formats.

Related Work

• Amethyst — Android Nostr client with Namecoin NIP-05 support
• Coracle PR #662 — Namecoin NIP-05 for Coracle web client
• NIP-05 spec
• Namecoin domain names