diff --git a/packages/ui/src/lib/gitHost.test.ts b/packages/ui/src/lib/gitHost.test.ts
new file mode 100644
index 00000000..9320b160
--- /dev/null
+++ b/packages/ui/src/lib/gitHost.test.ts
@@ -0,0 +1,73 @@
+import { describe, expect, test } from 'bun:test';
+import { parseGitHost } from './gitHost';
+
+describe('parseGitHost', () => {
+  test('scp-like form with user', () => {
+    expect(parseGitHost('git@codeberg.org:owner/repo.git')).toBe('codeberg.org');
+    expect(parseGitHost('git@git.example.com:group/repo.git')).toBe('git.example.com');
+  });
+
+  test('scp-like form without user (bare host:path)', () => {
+    expect(parseGitHost('codeberg.org:owner/repo.git')).toBe('codeberg.org');
+    expect(parseGitHost('git.example.com:group/repo.git')).toBe('git.example.com');
+  });
+
+  test('ssh URL with port', () => {
+    expect(parseGitHost('ssh://git@codeberg.org:2222/owner/repo.git')).toBe('codeberg.org');
+  });
+
+  test('git+ssh and git schemes', () => {
+    expect(parseGitHost('git+ssh://git@host/owner/repo.git')).toBe('host');
+    expect(parseGitHost('git://host/owner/repo.git')).toBe('host');
+  });
+
+  test('https with user and port', () => {
+    expect(parseGitHost('https://user@host:8443/owner/repo.git')).toBe('host');
+  });
+
+  test('IPv6 URL form returns the bare address', () => {
+    expect(parseGitHost('ssh://git@[2001:db8::1]/owner/repo.git')).toBe('2001:db8::1');
+    expect(parseGitHost('ssh://git@[2001:DB8::1]:2222/owner/repo.git')).toBe('2001:db8::1');
+  });
+
+  test('bracketed IPv6 input', () => {
+    expect(parseGitHost('[2001:db8::1]')).toBe('2001:db8::1');
+    expect(parseGitHost('[2001:db8::1]:owner/repo.git')).toBe('2001:db8::1');
+  });
+
+  test('unbracketed IPv6 input', () => {
+    expect(parseGitHost('2001:db8::1')).toBe('2001:db8::1');
+  });
+
+  test('plain hostname and hostname-with-user without a colon', () => {
+    expect(parseGitHost('git.example.com')).toBe('git.example.com');
+    expect(parseGitHost('git@host')).toBe('host');
+  });
+
+  test('hostname with trailing dot is stripped once', () => {
+    expect(parseGitHost('git.example.com.')).toBe('git.example.com');
+    expect(parseGitHost('ssh://git.example.com./owner/repo.git')).toBe('git.example.com');
+  });
+
+  test('input is trimmed', () => {
+    expect(parseGitHost('  codeberg.org:owner/repo.git  ')).toBe('codeberg.org');
+    expect(parseGitHost(' ssh://git@codeberg.org/owner/repo.git ')).toBe('codeberg.org');
+  });
+
+  test('empty, whitespace, and null input', () => {
+    expect(parseGitHost('')).toBeNull();
+    expect(parseGitHost('   ')).toBeNull();
+    expect(parseGitHost(' \t ')).toBeNull();
+    expect(parseGitHost(null as unknown as string)).toBeNull();
+  });
+
+  test('garbage input', () => {
+    expect(parseGitHost('not a url')).toBeNull();
+    expect(parseGitHost('ssh://not a url')).toBeNull();
+  });
+
+  test('Windows-path-like input is not a host', () => {
+    expect(parseGitHost('C:\\foo')).toBeNull();
+    expect(parseGitHost('C:\\foo\\bar.git')).toBeNull();
+  });
+});
diff --git a/packages/ui/src/lib/gitHost.ts b/packages/ui/src/lib/gitHost.ts
new file mode 100644
index 00000000..2e370b0a
--- /dev/null
+++ b/packages/ui/src/lib/gitHost.ts
@@ -0,0 +1,62 @@
+/**
+ * Parse a git remote or custom-domain string and return its bare hostname.
+ *
+ * Understands URL forms with any scheme (`https://`, `ssh://`, `git+ssh://`,
+ * `git://`, ...), scp-like forms with or without a `user@` prefix
+ * (`git@host:owner/repo.git`, `host:owner/repo.git`), and IPv6 addresses
+ * (bracketed or unbracketed). The result is normalized: lowercase, no
+ * surrounding IPv6 brackets, no scheme, port, or path, and at most one
+ * trailing dot stripped. Returns `null` for empty, whitespace, or unparseable
+ * input.
+ */
+export const parseGitHost = (raw: string): string | null => {
+  const value = (raw ?? '').trim();
+  if (!value) {
+    return null;
+  }
+
+  // scp-like form: [user@]host:path — never applies once a scheme is present.
+  if (!value.includes('://')) {
+    const authority = value.slice(value.lastIndexOf('@') + 1);
+    // Bracketed IPv6, e.g. `[2001:db8::1]` or `[2001:db8::1]:owner/repo.git`.
+    if (authority.startsWith('[')) {
+      const close = authority.indexOf(']');
+      if (close > 0 && authority.slice(1, close).includes(':')) {
+        return normalizeHost(authority.slice(1, close));
+      }
+      // Malformed brackets fall through to URL parsing, which rejects them.
+    } else {
+      const colon = authority.indexOf(':');
+      if (colon > 0) {
+        const candidate = authority.slice(0, colon);
+        // A single-segment pre-colon value without a dot is not a host — the
+        // guard rejects Windows paths like `C:\foo`, which then fall through
+        // to URL parsing and fail on the non-numeric port. Hosts with a
+        // numeric port (`localhost:3000`) still resolve via the URL branch.
+        if (!candidate.includes('/') && candidate.includes('.')) {
+          return normalizeHost(candidate);
+        }
+      }
+      // Unbracketed IPv6 (e.g. `2001:db8::1`): parse it as a bracketed host
+      // so the address survives instead of tripping over the scp colon split.
+      if (authority.includes(':') && !authority.includes('/') && authority.length > 2) {
+        try {
+          return normalizeHost(new URL(`ssh://[${authority}]`).hostname);
+        } catch {
+          // Not an IPv6 address; fall through to generic URL parsing.
+        }
+      }
+    }
+    // No colon or a non-host pre-colon segment: fall through to URL parsing.
+  }
+
+  try {
+    const parsed = new URL(value.includes('://') ? value : `ssh://${value}`);
+    return normalizeHost(parsed.hostname);
+  } catch {
+    return null;
+  }
+};
+
+const normalizeHost = (host: string): string =>
+  host.replace(/^\[|\]$/g, '').toLowerCase().replace(/\.$/, '');
diff --git a/packages/ui/src/lib/gitProvider.test.ts b/packages/ui/src/lib/gitProvider.test.ts
index 43882f27..aa0b9a62 100644
--- a/packages/ui/src/lib/gitProvider.test.ts
+++ b/packages/ui/src/lib/gitProvider.test.ts
@@ -58,6 +58,31 @@ describe('detectGitProvider', () => {
     expect(detectGitProvider(['git@codeberg.org:owner/repo.git'], hosts)).toBe('gitea');
   });
 
+  test('classifies a bare scp remote (no user) through configured gitea hosts', () => {
+    const hosts: GitProviderHosts = { ...EMPTY_HOSTS, gitea: ['codeberg.org'] };
+    expect(detectGitProvider(['codeberg.org:owner/repo.git'], hosts)).toBe('gitea');
+  });
+
+  test('classifies an ssh URL with a non-default port through configured gitea hosts', () => {
+    const hosts: GitProviderHosts = { ...EMPTY_HOSTS, gitea: ['codeberg.org'] };
+    expect(detectGitProvider(['ssh://git@codeberg.org:2222/owner/repo.git'], hosts)).toBe('gitea');
+  });
+
+  test('matches a custom domain entered as an scp remote against an ssh URL remote', () => {
+    const hosts: GitProviderHosts = { ...EMPTY_HOSTS, gitea: ['git@ssh.example.com:org/repo.git'] };
+    expect(detectGitProvider(['ssh://git@ssh.example.com/org/repo.git'], hosts)).toBe('gitea');
+  });
+
+  test('matches a custom domain entered bare against an scp remote', () => {
+    const hosts: GitProviderHosts = { ...EMPTY_HOSTS, gitea: ['codeberg.org:owner/repo.git'] };
+    expect(detectGitProvider(['git@codeberg.org:owner/repo.git'], hosts)).toBe('gitea');
+  });
+
+  test('classifies an IPv6 remote through a configured gitea host', () => {
+    const hosts: GitProviderHosts = { ...EMPTY_HOSTS, gitea: ['2001:db8::1'] };
+    expect(detectGitProvider(['ssh://git@[2001:db8::1]/owner/repo.git'], hosts)).toBe('gitea');
+  });
+
   test('does not classify codeberg.org as gitea without a configured host', () => {
     expect(detectGitProvider(['git@codeberg.org:owner/repo.git'], EMPTY_HOSTS)).toBe('other');
   });
diff --git a/packages/ui/src/lib/gitProvider.ts b/packages/ui/src/lib/gitProvider.ts
index eada3336..5d0777fc 100644
--- a/packages/ui/src/lib/gitProvider.ts
+++ b/packages/ui/src/lib/gitProvider.ts
@@ -1,4 +1,5 @@
 import { useEffect, useMemo, useState } from 'react';
+import { parseGitHost } from '@/lib/gitHost';
 import { getRemotes } from '@/lib/gitApi';
 import { useGitLabAuthStore } from '@/stores/useGitLabAuthStore';
 import { useGiteaAuthStore } from '@/stores/useGiteaAuthStore';
@@ -18,28 +19,6 @@ export type GitProviderHosts = {
   gitea: string[];
 };
 
-const parseGitRemoteHost = (value: string): string | null => {
-  const url = value.trim();
-  if (!url) {
-    return null;
-  }
-  // scp-like form: git@host:owner/repo.git
-  const at = url.indexOf('@');
-  if (at >= 0) {
-    const rest = url.slice(at + 1);
-    const colon = rest.indexOf(':');
-    if (colon > 0 && !rest.slice(0, colon).includes('/')) {
-      return rest.slice(0, colon).toLowerCase();
-    }
-  }
-  try {
-    const parsed = new URL(url.includes('://') ? url : `ssh://${url}`);
-    return parsed.hostname.toLowerCase();
-  } catch {
-    return null;
-  }
-};
-
 const normalizeHostList = (hosts: string[] | undefined): string[] => {
   const seen = new Set<string>();
   const result: string[] = [];
@@ -64,7 +43,7 @@ const normalizeHostList = (hosts: string[] | undefined): string[] => {
 export const detectGitProvider = (fetchUrls: string[], hosts: GitProviderHosts): GitProvider | null => {
   const remoteHosts = new Set<string>();
   for (const url of fetchUrls) {
-    const host = parseGitRemoteHost(url);
+    const host = parseGitHost(url);
     if (host) {
       remoteHosts.add(host);
     }
diff --git a/packages/ui/src/stores/useGitProviderDomainsStore.test.ts b/packages/ui/src/stores/useGitProviderDomainsStore.test.ts
new file mode 100644
index 00000000..45a666d3
--- /dev/null
+++ b/packages/ui/src/stores/useGitProviderDomainsStore.test.ts
@@ -0,0 +1,39 @@
+import { describe, expect, test } from 'bun:test';
+import { useGitProviderDomainsStore } from './useGitProviderDomainsStore';
+
+const resetDomains = () => {
+  useGitProviderDomainsStore.setState({
+    domains: { github: [], gitlab: [], gitea: [] },
+  });
+};
+
+describe('useGitProviderDomainsStore', () => {
+  test('normalizes and dedupes custom domains into bare hostnames', () => {
+    resetDomains();
+    useGitProviderDomainsStore.getState().setDomains('gitea', [
+      'git@codeberg.org:owner/repo.git',
+      'ssh://git@gitea.example.com:2222/o/r.git',
+      'https://g.example.com/x',
+      '  git.example.org  ',
+    ]);
+    expect(useGitProviderDomainsStore.getState().domains.gitea).toEqual([
+      'codeberg.org',
+      'gitea.example.com',
+      'g.example.com',
+      'git.example.org',
+    ]);
+  });
+
+  test('drops unparseable and duplicate entries', () => {
+    resetDomains();
+    useGitProviderDomainsStore.getState().setDomains('gitlab', [
+      'git@gitlab.example.com:group/repo.git',
+      'git@gitlab.example.com:group/repo.git',
+      '',
+      '   ',
+      'not a url',
+      'C:\\foo',
+    ]);
+    expect(useGitProviderDomainsStore.getState().domains.gitlab).toEqual(['gitlab.example.com']);
+  });
+});
diff --git a/packages/ui/src/stores/useGitProviderDomainsStore.ts b/packages/ui/src/stores/useGitProviderDomainsStore.ts
index 849bbe2e..325a461f 100644
--- a/packages/ui/src/stores/useGitProviderDomainsStore.ts
+++ b/packages/ui/src/stores/useGitProviderDomainsStore.ts
@@ -1,5 +1,6 @@
 import { create } from 'zustand';
 import { persist } from 'zustand/middleware';
+import { parseGitHost } from '@/lib/gitHost';
 import { createDeferredSafeJSONStorage } from './utils/safeStorage';
 
 export type GitProviderName = 'github' | 'gitlab' | 'gitea';
@@ -20,30 +21,11 @@ const EMPTY_DOMAINS: GitProviderDomains = { github: [], gitlab: [], gitea: [] };
 
 /**
  * Normalize a raw user-supplied domain into a bare hostname. Accepts plain
- * hostnames, URLs (scheme/port/path stripped), and scp-like git remotes
- * (`git@host:owner/repo.git`). Returns null for empty or unparseable input.
+ * hostnames, URLs (scheme/port/path stripped), and scp-like git remotes with
+ * or without a user prefix (`git@host:owner/repo.git`, `host:owner/repo.git`).
+ * Returns null for empty or unparseable input.
  */
-export const normalizeProviderDomain = (raw: string): string | null => {
-  const value = (raw ?? '').trim();
-  if (!value) {
-    return null;
-  }
-  // scp-like form: git@host:owner/repo.git
-  const at = value.indexOf('@');
-  if (at >= 0) {
-    const rest = value.slice(at + 1);
-    const colon = rest.indexOf(':');
-    if (colon > 0 && !rest.slice(0, colon).includes('/')) {
-      return rest.slice(0, colon).toLowerCase().replace(/\.$/, '');
-    }
-  }
-  try {
-    const parsed = new URL(value.includes('://') ? value : `ssh://${value}`);
-    return parsed.hostname.toLowerCase().replace(/\.$/, '');
-  } catch {
-    return null;
-  }
-};
+export const normalizeProviderDomain = (raw: string): string | null => parseGitHost(raw);
 
 const normalizeDomainList = (entries: unknown): string[] => {
   if (!Array.isArray(entries)) {