Add NIP-05 identifiers: store, publish, GUI modal, CLI helpers

- Store an optional nip05 on each profile; publish it in kind 0 metadata
- set-nip05 CLI (+ validation, lower-casing, clear) and nip05-file helper
  that prints the .well-known/nostr.json document for a domain
- Profiles screen: NIP-05 button, handle shown on cards, Nip05Modal with
  client-side validation and Remove action
- Fix Modal stealing focus from autoFocus inputs one frame after open

frontend/electron/main.ts

@@ -186,6 +186,7 @@ const RENDERER_METHODS: ReadonlySet<string> = new Set([
   'publish_profile_metadata',
   'set_profile_picture',
   'rename_profile',
+  'set_nip05',
   'delete_profile',
   'undo_delete',
   'publish_note',

frontend/src/components/Modal.tsx

@@ -19,7 +19,11 @@ export function Modal({ open, title, onClose, children }: ModalProps) {
     const container = containerRef.current;
 
     const frame = requestAnimationFrame(() => {
-      container?.focus();
+      // Keep keyboard focus where the user (or autoFocus) put it; only pull
+      // focus to the dialog itself as a fallback for content without inputs.
+      if (!container?.contains(document.activeElement)) {
+        container?.focus();
+      }
     });
 
     const onKeyDown = (event: KeyboardEvent) => {

frontend/src/lib/api.ts

@@ -63,6 +63,11 @@ export const api = {
       'rename_profile',
       { npub, label },
     ),
+  setNip05: (npub: string, nip05: string | null) =>
+    call<{ profile: ProfileSummary; report: MetadataPublishReport; state: AppState }>('set_nip05', {
+      npub,
+      nip05,
+    }),
   publishNote: (content: string) => call<PublishReport>('publish_note', { content }),
   feedGet: (limit?: number, contactsOnly = false) =>
     call<FeedItem[]>('feed_get', {

frontend/src/lib/types.ts

@@ -36,6 +36,8 @@ export interface ProfileSummary {
   is_active: boolean;
   /** Public URL of the profile picture, when one has been set. */
   picture?: string | null;
+  /** NIP-05 identifier (e.g. `boo@l484.com`), when one has been set. */
+  nip05?: string | null;
 }
 
 export interface RelayConfig {

frontend/src/screens/ProfilesScreen.tsx

@@ -25,6 +25,7 @@ export function ProfilesScreen({ onCreateProfile }: ProfilesScreenProps) {
   const [revealTarget, setRevealTarget] = useState<{ label: string; npub: string } | null>(null);
   const [pictureTarget, setPictureTarget] = useState<PictureTarget | null>(null);
   const [renameTarget, setRenameTarget] = useState<{ npub: string; label: string } | null>(null);
+  const [nip05Target, setNip05Target] = useState<Nip05Target | null>(null);
 
   const profiles = state?.profiles ?? [];
   const shorten = state?.settings.shorten_npub ?? true;
@@ -151,6 +152,11 @@ export function ProfilesScreen({ onCreateProfile }: ProfilesScreenProps) {
                 />
                 <div className="profile-card-meta">
                   <h3>{profile.label}</h3>
+                  {profile.nip05 && (
+                    <span className="nip05-handle" title={profile.nip05}>
+                      {profile.nip05}
+                    </span>
+                  )}
                   <code className="mono" title={profile.npub}>
                     {shortenNpub(profile.npub, shorten)}
                   </code>
@@ -177,6 +183,19 @@ export function ProfilesScreen({ onCreateProfile }: ProfilesScreenProps) {
                 >
                   <Icon name="edit" size={14} /> Edit name
                 </Button>
+                <Button
+                  variant="ghost"
+                  size="sm"
+                  onClick={() =>
+                    setNip05Target({
+                      npub: profile.npub,
+                      label: profile.label,
+                      nip05: profile.nip05 ?? '',
+                    })
+                  }
+                >
+                  <Icon name="edit" size={14} /> NIP-05
+                </Button>
                 <Button
                   variant="ghost"
                   size="sm"
@@ -260,6 +279,19 @@ export function ProfilesScreen({ onCreateProfile }: ProfilesScreenProps) {
             onSavingChange={setPublishing}
           />
         )}
+
+        {nip05Target && (
+          <Nip05Modal
+            target={nip05Target}
+            onClose={() => setNip05Target(null)}
+            onSaved={(message) => {
+              setNotice(message);
+              setNip05Target(null);
+            }}
+            onError={setError}
+            onSavingChange={setPublishing}
+          />
+        )}
       </div>
     </div>
   );
@@ -271,6 +303,119 @@ interface PictureTarget {
   url: string;
 }
 
+interface Nip05Target {
+  npub: string;
+  label: string;
+  nip05: string;
+}
+
+/** Client-side mirror of the backend's NIP-05 validation, for fast feedback. */
+function nip05Problem(value: string): string | null {
+  const trimmed = value.trim().toLowerCase();
+  if (!trimmed) {
+    return null; // Empty clears the identifier.
+  }
+  const at = trimmed.indexOf('@');
+  if (at <= 0 || at === trimmed.length - 1) {
+    return 'Use the form name@domain.com.';
+  }
+  const [local, domain] = [trimmed.slice(0, at), trimmed.slice(at + 1)];
+  if (local !== '_' && !/^[a-z0-9_-]+$/.test(local)) {
+    return 'The part before @ may only use letters, numbers, dashes and underscores.';
+  }
+  if (!/^[a-z0-9.-]+\.[a-z]{2,}$/.test(domain)) {
+    return 'The part after @ must be a domain like example.com.';
+  }
+  return null;
+}
+
+function Nip05Modal({
+  target,
+  onClose,
+  onSaved,
+  onError,
+  onSavingChange,
+}: {
+  target: Nip05Target;
+  onClose: () => void;
+  onSaved: (message: string) => void;
+  onError: (message: string | null) => void;
+  onSavingChange: (npub: string | null) => void;
+}) {
+  const { setNip05 } = useApp();
+  const [nip05, setNip05Value] = useState(target.nip05);
+  const [saving, setSaving] = useState(false);
+
+  const trimmed = nip05.trim();
+  const changed = trimmed !== target.nip05;
+  const problem = nip05Problem(trimmed);
+  const canSave = changed && !problem;
+
+  const save = async (next: string | null) => {
+    onError(null);
+    setSaving(true);
+    onSavingChange(target.npub);
+    try {
+      const report = await setNip05(target.npub, next);
+      onSaved(
+        report.failed.length === 0
+          ? next
+            ? `NIP-05 "${next}" published to ${report.succeeded.length} relay(s). Remember it must also be served from your domain (see docs/NIP-05.md).`
+            : 'NIP-05 removed and the change published.'
+          : `NIP-05 saved for "${target.label}", but ${report.failed.length} relay(s) did not accept it. Use "Publish name" to retry.`,
+      );
+    } catch (err) {
+      onError(err instanceof Error ? err.message : String(err));
+    } finally {
+      setSaving(false);
+      onSavingChange(null);
+    }
+  };
+
+  return (
+    <Modal open title={`NIP-05 address — ${target.label}`} onClose={onClose}>
+      <div className="picture-modal">
+        <div className="field">
+          <label htmlFor="profile-nip05">NIP-05 address</label>
+          <input
+            id="profile-nip05"
+            type="text"
+            value={nip05}
+            onChange={(event) => setNip05Value(event.target.value)}
+            placeholder="name@domain.com"
+            autoComplete="off"
+            autoFocus
+          />
+          {problem && trimmed && <ErrorText>{problem}</ErrorText>}
+        </div>
+        <p className="muted">
+          A NIP-05 address (like an email handle) makes clients show a proper username instead of a
+          raw key. It is published to your relays and must also be served from your domain as
+          <code> /.well-known/nostr.json</code> — see <code>docs/NIP-05.md</code>.
+        </p>
+        <div className="modal-actions">
+          {target.nip05 && (
+            <Button variant="danger" onClick={() => void save(null)} disabled={saving}>
+              Remove
+            </Button>
+          )}
+          <Button variant="ghost" onClick={onClose} disabled={saving}>
+            Cancel
+          </Button>
+          <Button
+            variant="primary"
+            onClick={() => void save(trimmed ? trimmed.toLowerCase() : null)}
+            loading={saving}
+            disabled={!canSave}
+          >
+            Save &amp; publish
+          </Button>
+        </div>
+      </div>
+    </Modal>
+  );
+}
+
 function RenameModal({
   target,
   onClose,

frontend/src/state/AppProvider.tsx

@@ -42,6 +42,7 @@ interface AppContextValue {
   publishProfileMetadata: (npub: string) => Promise<MetadataPublishReport>;
   setProfilePicture: (npub: string, url: string | null) => Promise<MetadataPublishReport>;
   renameProfile: (npub: string, label: string) => Promise<MetadataPublishReport>;
+  setNip05: (npub: string, nip05: string | null) => Promise<MetadataPublishReport>;
   publishNote: (content: string) => Promise<PublishReport>;
   recordPublishFailure: (message: string, details?: string | null) => void;
   clearLastPublish: () => void;
@@ -144,6 +145,15 @@ export function AppProvider({ children }: { children: ReactNode }) {
     [],
   );
 
+  const setNip05 = useCallback(
+    async (npub: string, nip05: string | null): Promise<MetadataPublishReport> => {
+      const result = await api.setNip05(npub, nip05);
+      setState(result.state);
+      return result.report;
+    },
+    [],
+  );
+
   const publishNote = useCallback(async (content: string): Promise<PublishReport> => {
     const report = await api.publishNote(content);
     setLastPublish({ report, error: null, details: null, at: Date.now() });
@@ -261,6 +271,7 @@ export function AppProvider({ children }: { children: ReactNode }) {
       publishProfileMetadata,
       setProfilePicture,
       renameProfile,
+      setNip05,
       copyText,
     }),
     [
@@ -274,6 +285,7 @@ export function AppProvider({ children }: { children: ReactNode }) {
       publishProfileMetadata,
       setProfilePicture,
       renameProfile,
+      setNip05,
       publishNote,
       deleteProfile,
       undoDelete,

frontend/src/test/ProfilesScreen.test.tsx

@@ -86,6 +86,69 @@ describe('ProfilesScreen', () => {
     expect(await screen.findByRole('status')).toHaveTextContent(/Renamed to "Bobby"/);
   });
 
+  it('sets a NIP-05 address from the NIP-05 modal and publishes it', async () => {
+    const backend = createFakeBackend();
+    installFakeBackend(backend);
+    const user = userEvent.setup();
+    renderWithApp(<ProfilesScreen onCreateProfile={vi.fn()} />);
+
+    await screen.findByText('Bob');
+    await user.click(screen.getAllByRole('button', { name: 'NIP-05' })[1]);
+
+    const input = screen.getByLabelText('NIP-05 address');
+    expect(input).toHaveValue('');
+    await user.type(input, 'Bob@Example.com');
+    await user.click(screen.getByRole('button', { name: 'Save & publish' }));
+
+    await waitFor(() => {
+      expect(backend.state.profiles.find((p) => p.npub === BOB)?.nip05).toBe('bob@example.com');
+    });
+    expect(await screen.findByRole('status')).toHaveTextContent(/NIP-05 "bob@example.com"/);
+    expect(await screen.findByText('bob@example.com')).toBeInTheDocument();
+  });
+
+  it('rejects a malformed NIP-05 address without calling the backend', async () => {
+    const backend = createFakeBackend();
+    installFakeBackend(backend);
+    const user = userEvent.setup();
+    renderWithApp(<ProfilesScreen onCreateProfile={vi.fn()} />);
+
+    await screen.findByText('Bob');
+    await user.click(screen.getAllByRole('button', { name: 'NIP-05' })[1]);
+
+    const input = screen.getByLabelText('NIP-05 address');
+    await user.type(input, 'not-an-address');
+    expect(screen.getByRole('button', { name: 'Save & publish' })).toBeDisabled();
+
+    await user.clear(input);
+    await user.type(input, 'boo@nodot');
+    expect(screen.getByRole('button', { name: 'Save & publish' })).toBeDisabled();
+    expect(backend.requests.filter((r) => r.method === 'set_nip05')).toHaveLength(0);
+  });
+
+  it('removes an existing NIP-05 address', async () => {
+    const backend = createFakeBackend();
+    installFakeBackend(backend);
+    backend.setState({
+      ...backend.state,
+      profiles: backend.state.profiles.map((p) =>
+        p.npub === BOB ? { ...p, nip05: 'bob@example.com' } : p,
+      ),
+      active_profile: backend.state.active_profile,
+    });
+    const user = userEvent.setup();
+    renderWithApp(<ProfilesScreen onCreateProfile={vi.fn()} />);
+
+    await screen.findByText('bob@example.com');
+    await user.click(screen.getAllByRole('button', { name: 'NIP-05' })[1]);
+    await user.click(screen.getByRole('button', { name: 'Remove' }));
+
+    await waitFor(() => {
+      expect(backend.state.profiles.find((p) => p.npub === BOB)?.nip05).toBeNull();
+    });
+    expect(await screen.findByRole('status')).toHaveTextContent(/NIP-05 removed/i);
+  });
+
   it('disables Select for the active profile and copies public keys', async () => {
     const backend = createFakeBackend();
     installFakeBackend(backend);

frontend/src/test/fakeBackend.ts

@@ -182,6 +182,39 @@ export function createFakeBackend(initial?: AppState): FakeBackend {
         return { profile: updated, report: makePublishReport(), state: next };
       }
 
+      case 'set_nip05': {
+        const npub = String(params.npub);
+        const raw = params.nip05;
+        const nip05 = typeof raw === 'string' ? raw.trim().toLowerCase() : null;
+        if (nip05) {
+          const at = nip05.indexOf('@');
+          const [local, domain] = [nip05.slice(0, at), nip05.slice(at + 1)];
+          if (at <= 0 || at === nip05.length - 1 || nip05.includes('@', at + 1)) {
+            throw new Error('A NIP-05 address must look like name@domain.com.');
+          }
+          if (local !== '_' && !/^[a-z0-9_-]+$/.test(local)) {
+            throw new Error(
+              'The part before @ may only use letters, numbers, dashes and underscores.',
+            );
+          }
+          if (!domain.includes('.') || domain.split('.').some((part) => !part)) {
+            throw new Error('The part after @ must be a domain like example.com.');
+          }
+        }
+        const existing = state.profiles.find((p) => p.npub === npub);
+        if (!existing) {
+          throw new Error('That profile is not stored on this computer.');
+        }
+        const updated: ProfileSummary = { ...existing, nip05: nip05 || null };
+        const next: AppState = {
+          ...state,
+          profiles: state.profiles.map((p) => (p.npub === npub ? updated : p)),
+          active_profile: state.active_profile?.npub === npub ? updated : state.active_profile,
+        };
+        backend.setState(next);
+        return { profile: updated, report: makePublishReport(), state: next };
+      }
+
       case 'publish_note': {
         if (publishFailure) {
           const failure = publishFailure;