add did:nostr resolution endpoint (.well-known/did/nostr/:pubkey.json) via conformant builder + tests

Author: melvincarvalho

src/diddoc.js

@@ -0,0 +1,65 @@
+// Build a spec-conformant did:nostr DID document from indexed events.
+//
+// Implements the current spec (https://nostrcg.github.io/did-nostr/):
+//   - @context: cid/v1 + nostr/context   (cf. nostrcg/did-nostr#90/#91)
+//   - type: DIDNostr
+//   - Multikey VM with publicKeyMultibase = f + e701 + 02 + <x-only hex>
+//   - enhanced: profile (kind 0), follows (kind 3), service/Relay (kind 10002)
+//
+// Per RFC JavaScriptSolidServer/JavaScriptSolidServer#572 this is intended to
+// converge with jss's shared `buildDidDocument` once that is extracted as a
+// reusable module; until then beacon builds the conformant doc directly so it
+// is correct now (and avoids the divergent-generator bugs of nostr-labs/nostr-beacon#3).
+
+const HEX64 = /^[0-9a-f]{64}$/;
+
+export function buildDidDocument(pubkey, { profile, follows, relays } = {}) {
+  const hex = String(pubkey || '').toLowerCase();
+  if (!HEX64.test(hex)) return null;
+  const did = `did:nostr:${hex}`;
+
+  const doc = {
+    '@context': ['https://www.w3.org/ns/cid/v1', 'https://w3id.org/nostr/context'],
+    id: did,
+    type: 'DIDNostr',
+    verificationMethod: [{
+      id: `${did}#key1`,
+      type: 'Multikey',
+      controller: did,
+      publicKeyMultibase: `fe70102${hex}`,
+    }],
+    authentication: ['#key1'],
+    assertionMethod: ['#key1'],
+  };
+
+  // kind 0 -> profile (+ alsoKnownAs)
+  if (profile?.content) {
+    try {
+      const c = JSON.parse(profile.content);
+      const p = {};
+      for (const k of ['name', 'about', 'picture', 'website', 'nip05', 'lud16']) if (c[k]) p[k] = c[k];
+      if (c.display_name && !p.name) p.name = c.display_name;
+      if (profile.created_at) p.timestamp = profile.created_at;
+      if (Object.keys(p).length) doc.profile = p;
+      if (Array.isArray(c.alsoKnownAs) && c.alsoKnownAs.length) doc.alsoKnownAs = c.alsoKnownAs;
+    } catch { /* malformed kind-0 content */ }
+  }
+
+  // kind 3 -> follows (did:nostr of each p-tag)
+  if (Array.isArray(follows?.tags)) {
+    const f = follows.tags
+      .filter((t) => t[0] === 'p' && HEX64.test(String(t[1]).toLowerCase()))
+      .map((t) => `did:nostr:${String(t[1]).toLowerCase()}`);
+    if (f.length) doc.follows = f;
+  }
+
+  // kind 10002 -> service (Relay)
+  if (Array.isArray(relays?.tags)) {
+    const svc = relays.tags
+      .filter((t) => t[0] === 'r' && t[1])
+      .map((t, i) => ({ id: `${did}#relay${i + 1}`, type: 'Relay', serviceEndpoint: t[1] }));
+    if (svc.length) doc.service = svc;
+  }
+
+  return doc;
+}

src/server.js

@@ -1,6 +1,7 @@
 // Thin read API over the indexed social graph.
 import express from 'express';
 import { getProfile, getFollows, getRelays, recentProfiles, connect } from './db.js';
+import { buildDidDocument } from './diddoc.js';
 import 'dotenv/config';
 
 export async function startServer(port = process.env.PORT || 3000) {
@@ -20,6 +21,29 @@ export async function startServer(port = process.env.PORT || 3000) {
     try { res.json(await getRelays(req.params.pubkey)); } catch (e) { next(e); }
   });
 
+  // did:nostr resolution — build the conformant DID document from the index
+  const resolve = async (pubkey) => {
+    const [profile, follows, relays] = await Promise.all([
+      getProfile(pubkey), getFollows(pubkey), getRelays(pubkey),
+    ]);
+    return buildDidDocument(pubkey, { profile, follows, relays });
+  };
+  app.get('/.well-known/did/nostr/:pubkey.json', async (req, res, next) => {
+    try {
+      const doc = await resolve(req.params.pubkey);
+      if (!doc) return res.status(400).json({ error: 'invalid did:nostr pubkey (expect 64-hex)' });
+      res.setHeader('Content-Type', 'application/did+json');
+      res.json(doc);
+    } catch (e) { next(e); }
+  });
+  app.get('/api/did/:pubkey', async (req, res, next) => {
+    try {
+      const doc = await resolve(req.params.pubkey);
+      if (!doc) return res.status(400).json({ error: 'invalid did:nostr pubkey (expect 64-hex)' });
+      res.json(doc);
+    } catch (e) { next(e); }
+  });
+
   app.use((err, _req, res, _next) => res.status(500).json({ error: err.message }));
   app.listen(port, () => console.log(`[beacon] read API on :${port}`));
   return app;

test/diddoc.test.js

@@ -0,0 +1,38 @@
+// Unit tests for the conformant did:nostr DID-document builder (no Mongo needed).
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { buildDidDocument } from '../src/diddoc.js';
+
+const PK = '124c0fa99407182ece5a24fad9b7f6674902fc422843d3128d38a0afbee0fdd2';
+
+test('minimal doc is spec-shaped (cid/v1, Multikey, publicKeyMultibase)', () => {
+  const d = buildDidDocument(PK);
+  assert.deepEqual(d['@context'], ['https://www.w3.org/ns/cid/v1', 'https://w3id.org/nostr/context']);
+  assert.equal(d.id, `did:nostr:${PK}`);
+  assert.equal(d.type, 'DIDNostr');
+  assert.equal(d.verificationMethod[0].type, 'Multikey');
+  assert.equal(d.verificationMethod[0].publicKeyMultibase, `fe70102${PK}`);
+  assert.equal(d.verificationMethod[0].id, `did:nostr:${PK}#key1`);
+  assert.deepEqual(d.authentication, ['#key1']);
+  assert.deepEqual(d.assertionMethod, ['#key1']);
+});
+
+test('enhanced: profile (kind 0), follows (kind 3), service (kind 10002)', () => {
+  const follow = 'a'.repeat(64);
+  const d = buildDidDocument(PK, {
+    profile: { content: JSON.stringify({ name: 'Alice', nip05: 'alice@example.com' }), created_at: 100 },
+    follows: { tags: [['p', follow], ['e', 'ignored']] },
+    relays: { tags: [['r', 'wss://relay.example/']] },
+  });
+  assert.equal(d.profile.name, 'Alice');
+  assert.equal(d.profile.nip05, 'alice@example.com');
+  assert.equal(d.profile.timestamp, 100);
+  assert.deepEqual(d.follows, [`did:nostr:${follow}`]);
+  assert.equal(d.service[0].type, 'Relay');
+  assert.equal(d.service[0].serviceEndpoint, 'wss://relay.example/');
+});
+
+test('rejects a non-hex (e.g. npub) identifier', () => {
+  assert.equal(buildDidDocument('npub1xxx'), null);
+  assert.equal(buildDidDocument(''), null);
+});