diff --git a/hbd/server/oauth.py b/hbd/server/oauth.py
index 60f7d2d..026b921 100644
--- a/hbd/server/oauth.py
+++ b/hbd/server/oauth.py
@@ -1,17 +1,30 @@
-"""Gitea OAuth2 support.
+"""OAuth2 provider support.
 
 Config shape (in ~/.hb.yaml):
 
     oauth:
-      gitea:
-        url: https://git.example.com
+      my-gitea:                          # route slug → /login/oauth/my-gitea
+        type: gitea                      # "gitea" | "github" | "nextcloud"
+                                         # omit type to default to "gitea"
+        url: https://git.example.com     # required for gitea and nextcloud
+        client_id: <client-id>
+        client_secret: <client-secret>
+        label: "Work Gitea"              # optional display name on login button
+        logo: https://example.com/logo.png  # optional logo URL
+
+      github:
+        type: github
         client_id: <client-id>
         client_secret: <client-secret>
 
-Register a Gitea OAuth2 application at:
-  Gitea → Settings → Applications → OAuth2
-Set the redirect URI to:
-  https://<hbd-host>/login/oauth/gitea/callback
+      nextcloud:
+        type: nextcloud
+        url: https://cloud.example.com
+        client_id: <client-id>
+        client_secret: <client-secret>
+
+Register the OAuth app with each provider and set the redirect URI to:
+  https://<hbd-host>/login/oauth/<name>/callback
 """
 
 import logging
@@ -155,44 +168,32 @@ def get_providers(config: dict) -> list[ResolvedProvider]:
     return result
 
 
-def _gitea_cfg(config: dict) -> dict:
-    """Return the gitea sub-dict or {} if absent/incomplete."""
-    return config.get("oauth", {}).get("gitea", {})
-
-
 def is_enabled(config: dict) -> bool:
-    """Return True when all three required Gitea OAuth keys are present."""
-    g = _gitea_cfg(config)
-    return bool(g.get("url") and g.get("client_id") and g.get("client_secret"))
+    """Return True when at least one OAuth provider is fully configured."""
+    return bool(get_providers(config))
 
 
-def authorization_url(config: dict, state: str, redirect_uri: str) -> str:
-    """Return the Gitea OAuth2 authorization URL to redirect the browser to."""
-    g = _gitea_cfg(config)
-    if not (g.get("url") and g.get("client_id") and g.get("client_secret")):
-        raise OAuthError("Gitea OAuth2 is not configured")
-    params = urllib.parse.urlencode({
-        "client_id": g["client_id"],
+def build_auth_url(provider: ResolvedProvider, state: str, redirect_uri: str) -> str:
+    """Return the provider's OAuth2 authorization URL to redirect the browser to."""
+    params: dict = {
+        "client_id": provider.client_id,
         "redirect_uri": redirect_uri,
         "response_type": "code",
-        "scope": "user:email",
         "state": state,
-    })
-    return f"{g['url'].rstrip('/')}/login/oauth/authorize?{params}"
+    }
+    if provider.scope:
+        params["scope"] = provider.scope
+    return f"{provider.authorize_url}?{urllib.parse.urlencode(params)}"
 
 
-async def exchange_code(config: dict, code: str, redirect_uri: str) -> str:
-    """Exchange an authorization *code* for a Gitea access token.
+async def exchange_code(provider: ResolvedProvider, code: str, redirect_uri: str) -> str:
+    """Exchange an authorization *code* for an access token.
 
     Returns the access token string.  Raises OAuthError on any failure.
     """
-    g = _gitea_cfg(config)
-    if not (g.get("url") and g.get("client_id") and g.get("client_secret")):
-        raise OAuthError("Gitea OAuth2 is not configured")
-    url = f"{g['url'].rstrip('/')}/login/oauth/access_token"
     payload = {
-        "client_id": g["client_id"],
-        "client_secret": g["client_secret"],
+        "client_id": provider.client_id,
+        "client_secret": provider.client_secret,
         "code": code,
         "grant_type": "authorization_code",
         "redirect_uri": redirect_uri,
@@ -200,7 +201,11 @@ async def exchange_code(config: dict, code: str, redirect_uri: str) -> str:
     timeout = aiohttp.ClientTimeout(total=10)
     try:
         async with aiohttp.ClientSession(timeout=timeout) as session:
-            async with session.post(url, json=payload, headers={"Accept": "application/json"}) as resp:
+            async with session.post(
+                provider.token_url,
+                json=payload,
+                headers={"Accept": "application/json"},
+            ) as resp:
                 if resp.status != 200:
                     text = await resp.text()
                     raise OAuthError(f"Token exchange failed ({resp.status}): {text}")
@@ -213,28 +218,35 @@ async def exchange_code(config: dict, code: str, redirect_uri: str) -> str:
     return token
 
 
-async def fetch_user(config: dict, token: str) -> dict:
-    """Fetch the authenticated user's profile from Gitea.
+async def fetch_user(provider: ResolvedProvider, token: str) -> dict:
+    """Fetch the authenticated user's profile from the provider.
 
     Returns a dict with keys: login, full_name, avatar_url.
     Raises OAuthError on any failure.
     """
-    g = _gitea_cfg(config)
-    if not (g.get("url") and g.get("client_id") and g.get("client_secret")):
-        raise OAuthError("Gitea OAuth2 is not configured")
-    url = f"{g['url'].rstrip('/')}/api/v1/user"
     timeout = aiohttp.ClientTimeout(total=10)
     try:
         async with aiohttp.ClientSession(timeout=timeout) as session:
-            async with session.get(url, headers={"Authorization": f"token {token}"}) as resp:
+            async with session.get(
+                provider.profile_url,
+                headers={
+                    "Authorization": f"Bearer {token}",
+                    "Accept": "application/json",
+                },
+            ) as resp:
                 if resp.status != 200:
                     text = await resp.text()
                     raise OAuthError(f"User fetch failed ({resp.status}): {text}")
                 data = await resp.json()
     except aiohttp.ClientError as exc:
         raise OAuthError(f"User fetch network error: {exc}") from exc
+
+    for key in provider.profile_data_path:
+        data = data.get(key, {})
+
+    avatar_field = provider.field_map.get("avatar")
     return {
-        "login": data.get("login", ""),
-        "full_name": data.get("full_name", ""),
-        "avatar_url": data.get("avatar_url", ""),
+        "login":      data.get(provider.field_map["username"], ""),
+        "full_name":  data.get(provider.field_map["full_name"], ""),
+        "avatar_url": data.get(avatar_field, "") if avatar_field else "",
     }
diff --git a/tests/test_oauth.py b/tests/test_oauth.py
index c9d0ee1..df479c7 100644
--- a/tests/test_oauth.py
+++ b/tests/test_oauth.py
@@ -37,17 +37,6 @@ def reset_users_dict():
     users_mod.users = original
 
 
-def test_is_enabled_when_all_keys_present():
-    assert oauth.is_enabled(CFG_ON) is True
-
-
-def test_is_enabled_false_when_no_oauth_key():
-    assert oauth.is_enabled(CFG_OFF) is False
-
-
-def test_is_enabled_false_when_partial_config():
-    assert oauth.is_enabled(CFG_PARTIAL) is False
-
 
 def test_make_state_returns_unique_tokens():
     s1 = oauth.make_state()
@@ -135,132 +124,6 @@ def test_provision_oauth_user_survives_config_reload():
     assert "oauthonly" in users_mod.users
 
 
-def test_authorization_url_shape():
-    state = "teststate"
-    redirect_uri = "https://hbd.example.com/login/oauth/gitea/callback"
-    url = oauth.authorization_url(CFG_ON, state, redirect_uri)
-    parsed = urlparse(url)
-    qs = parse_qs(parsed.query)
-    assert parsed.scheme == "https"
-    assert parsed.netloc == "git.example.com"
-    assert parsed.path == "/login/oauth/authorize"
-    assert qs["client_id"] == ["cid"]
-    assert qs["state"] == ["teststate"]
-    assert qs["redirect_uri"] == [redirect_uri]
-    assert qs["scope"] == ["user:email"]
-    assert qs["response_type"] == ["code"]
-
-
-@pytest.mark.asyncio
-async def test_exchange_code_returns_token():
-    redirect_uri = "https://hbd.example.com/login/oauth/gitea/callback"
-    mock_response = AsyncMock()
-    mock_response.status = 200
-    mock_response.json = AsyncMock(return_value={"access_token": "tok123"})
-
-    mock_session = MagicMock()
-    mock_session.post = MagicMock(return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_response),
-        __aexit__=AsyncMock(return_value=False),
-    ))
-
-    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_session),
-        __aexit__=AsyncMock(return_value=False),
-    )):
-        token = await oauth.exchange_code(CFG_ON, "mycode", redirect_uri)
-    assert token == "tok123"
-
-
-@pytest.mark.asyncio
-async def test_exchange_code_raises_on_error_status():
-    redirect_uri = "https://hbd.example.com/login/oauth/gitea/callback"
-    mock_response = AsyncMock()
-    mock_response.status = 401
-    mock_response.text = AsyncMock(return_value="unauthorized")
-
-    mock_session = MagicMock()
-    mock_session.post = MagicMock(return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_response),
-        __aexit__=AsyncMock(return_value=False),
-    ))
-
-    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_session),
-        __aexit__=AsyncMock(return_value=False),
-    )):
-        with pytest.raises(oauth.OAuthError):
-            await oauth.exchange_code(CFG_ON, "badcode", redirect_uri)
-
-
-@pytest.mark.asyncio
-async def test_fetch_user_returns_profile():
-    mock_response = AsyncMock()
-    mock_response.status = 200
-    mock_response.json = AsyncMock(return_value={
-        "login": "alice",
-        "full_name": "Alice Smith",
-        "avatar_url": "https://git.example.com/avatars/alice.png",
-    })
-
-    mock_session = MagicMock()
-    mock_session.get = MagicMock(return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_response),
-        __aexit__=AsyncMock(return_value=False),
-    ))
-
-    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_session),
-        __aexit__=AsyncMock(return_value=False),
-    )):
-        profile = await oauth.fetch_user(CFG_ON, "tok123")
-    assert profile == {
-        "login": "alice",
-        "full_name": "Alice Smith",
-        "avatar_url": "https://git.example.com/avatars/alice.png",
-    }
-
-
-@pytest.mark.asyncio
-async def test_exchange_code_raises_when_no_access_token():
-    redirect_uri = "https://hbd.example.com/login/oauth/gitea/callback"
-    mock_response = AsyncMock()
-    mock_response.status = 200
-    mock_response.json = AsyncMock(return_value={"error": "bad_request"})
-
-    mock_session = MagicMock()
-    mock_session.post = MagicMock(return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_response),
-        __aexit__=AsyncMock(return_value=False),
-    ))
-
-    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_session),
-        __aexit__=AsyncMock(return_value=False),
-    )):
-        with pytest.raises(oauth.OAuthError):
-            await oauth.exchange_code(CFG_ON, "mycode", redirect_uri)
-
-
-@pytest.mark.asyncio
-async def test_fetch_user_raises_on_error_status():
-    mock_response = AsyncMock()
-    mock_response.status = 401
-    mock_response.text = AsyncMock(return_value="unauthorized")
-
-    mock_session = MagicMock()
-    mock_session.get = MagicMock(return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_response),
-        __aexit__=AsyncMock(return_value=False),
-    ))
-
-    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
-        __aenter__=AsyncMock(return_value=mock_session),
-        __aexit__=AsyncMock(return_value=False),
-    )):
-        with pytest.raises(oauth.OAuthError):
-            await oauth.fetch_user(CFG_ON, "tok123")
-
 
 # ---------------------------------------------------------------------------
 # Integration-style tests: callback logic chain
@@ -277,13 +140,12 @@ async def test_callback_invalid_state_rejects():
 @pytest.mark.asyncio
 async def test_full_oauth_flow_chain():
     """Integration-style test: state → exchange → fetch → provision chain."""
+    p = _gitea_provider()
     redirect_uri = "https://hbd.example.com/login/oauth/gitea/callback"
 
-    # Step 1: create a state token
     state = oauth.make_state()
-    assert oauth.validate_state(state) is True  # consumed; replay would return False
+    assert oauth.validate_state(state) is True
 
-    # Step 2: exchange code → token (mocked)
     mock_token_response = AsyncMock()
     mock_token_response.status = 200
     mock_token_response.json = AsyncMock(return_value={"access_token": "flow_token"})
@@ -310,13 +172,12 @@ async def test_full_oauth_flow_chain():
         __aenter__=AsyncMock(return_value=mock_session),
         __aexit__=AsyncMock(return_value=False),
     )):
-        token = await oauth.exchange_code(CFG_ON, "authcode", redirect_uri)
-        profile = await oauth.fetch_user(CFG_ON, token)
+        token = await oauth.exchange_code(p, "authcode", redirect_uri)
+        profile = await oauth.fetch_user(p, token)
 
     assert token == "flow_token"
     assert profile["login"] == "flowuser"
 
-    # Step 3: provision user
     _reset_users()
     user = users_mod.provision_oauth_user(
         profile["login"], profile["full_name"], profile["avatar_url"]
@@ -473,3 +334,268 @@ def test_get_providers_skips_unknown_type(caplog):
 def test_get_providers_empty_config():
     assert oauth.get_providers({}) == []
     assert oauth.get_providers(CFG_OFF) == []
+
+
+# ---------------------------------------------------------------------------
+# build_auth_url / exchange_code / fetch_user (generic, ResolvedProvider-based)
+# ---------------------------------------------------------------------------
+
+def _gitea_provider() -> oauth.ResolvedProvider:
+    return oauth.get_providers(CFG_ON)[0]
+
+
+def _github_provider() -> oauth.ResolvedProvider:
+    return oauth.get_providers(CFG_GITHUB)[0]
+
+
+def _nextcloud_provider() -> oauth.ResolvedProvider:
+    return oauth.get_providers(CFG_NEXTCLOUD)[0]
+
+
+def test_build_auth_url_gitea():
+    p = _gitea_provider()
+    url = oauth.build_auth_url(p, "teststate", "https://hbd.example.com/login/oauth/gitea/callback")
+    parsed = urlparse(url)
+    qs = parse_qs(parsed.query)
+    assert parsed.netloc == "git.example.com"
+    assert parsed.path == "/login/oauth/authorize"
+    assert qs["client_id"] == ["cid"]
+    assert qs["state"] == ["teststate"]
+    assert qs["scope"] == ["user:email"]
+    assert qs["response_type"] == ["code"]
+
+
+def test_build_auth_url_github():
+    p = _github_provider()
+    url = oauth.build_auth_url(p, "st", "https://hbd.example.com/login/oauth/github/callback")
+    parsed = urlparse(url)
+    qs = parse_qs(parsed.query)
+    assert parsed.netloc == "github.com"
+    assert qs["scope"] == ["read:user"]
+
+
+def test_build_auth_url_nextcloud_no_scope_param():
+    """Nextcloud scope is empty — the 'scope' key must be absent from the URL."""
+    p = _nextcloud_provider()
+    url = oauth.build_auth_url(p, "st", "https://hbd.example.com/login/oauth/nc/callback")
+    qs = parse_qs(urlparse(url).query)
+    assert "scope" not in qs
+
+
+@pytest.mark.asyncio
+async def test_exchange_code_generic_returns_token():
+    p = _gitea_provider()
+    redirect_uri = "https://hbd.example.com/login/oauth/gitea/callback"
+    mock_response = AsyncMock()
+    mock_response.status = 200
+    mock_response.json = AsyncMock(return_value={"access_token": "tok123"})
+
+    mock_session = MagicMock()
+    mock_session.post = MagicMock(return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_response),
+        __aexit__=AsyncMock(return_value=False),
+    ))
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        token = await oauth.exchange_code(p, "mycode", redirect_uri)
+    assert token == "tok123"
+
+
+@pytest.mark.asyncio
+async def test_exchange_code_sends_accept_json():
+    """Accept: application/json must be present for all providers (required by GitHub)."""
+    p = _github_provider()
+    captured_headers = {}
+
+    mock_response = AsyncMock()
+    mock_response.status = 200
+    mock_response.json = AsyncMock(return_value={"access_token": "ghtoken"})
+
+    mock_session = MagicMock()
+
+    def capture_post(url, **kwargs):
+        captured_headers.update(kwargs.get("headers", {}))
+        return AsyncMock(
+            __aenter__=AsyncMock(return_value=mock_response),
+            __aexit__=AsyncMock(return_value=False),
+        )
+
+    mock_session.post = capture_post
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        await oauth.exchange_code(p, "code", "https://hbd.example.com/login/oauth/github/callback")
+
+    assert captured_headers.get("Accept") == "application/json"
+
+
+@pytest.mark.asyncio
+async def test_exchange_code_raises_on_error_status():
+    p = _gitea_provider()
+    mock_response = AsyncMock()
+    mock_response.status = 401
+    mock_response.text = AsyncMock(return_value="unauthorized")
+
+    mock_session = MagicMock()
+    mock_session.post = MagicMock(return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_response),
+        __aexit__=AsyncMock(return_value=False),
+    ))
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        with pytest.raises(oauth.OAuthError):
+            await oauth.exchange_code(p, "badcode", "https://hbd.example.com/login/oauth/gitea/callback")
+
+
+@pytest.mark.asyncio
+async def test_exchange_code_raises_when_no_access_token():
+    p = _gitea_provider()
+    mock_response = AsyncMock()
+    mock_response.status = 200
+    mock_response.json = AsyncMock(return_value={"error": "bad_request"})
+
+    mock_session = MagicMock()
+    mock_session.post = MagicMock(return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_response),
+        __aexit__=AsyncMock(return_value=False),
+    ))
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        with pytest.raises(oauth.OAuthError):
+            await oauth.exchange_code(p, "mycode", "https://hbd.example.com/login/oauth/gitea/callback")
+
+
+@pytest.mark.asyncio
+async def test_fetch_user_gitea_returns_profile():
+    p = _gitea_provider()
+    mock_response = AsyncMock()
+    mock_response.status = 200
+    mock_response.json = AsyncMock(return_value={
+        "login": "alice",
+        "full_name": "Alice Smith",
+        "avatar_url": "https://git.example.com/avatars/alice.png",
+    })
+
+    mock_session = MagicMock()
+    mock_session.get = MagicMock(return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_response),
+        __aexit__=AsyncMock(return_value=False),
+    ))
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        profile = await oauth.fetch_user(p, "tok123")
+
+    assert profile == {
+        "login": "alice",
+        "full_name": "Alice Smith",
+        "avatar_url": "https://git.example.com/avatars/alice.png",
+    }
+
+
+@pytest.mark.asyncio
+async def test_fetch_user_github_maps_name_field():
+    p = _github_provider()
+    mock_response = AsyncMock()
+    mock_response.status = 200
+    mock_response.json = AsyncMock(return_value={
+        "login": "bobgh",
+        "name": "Bob GitHub",
+        "avatar_url": "https://avatars.githubusercontent.com/u/1",
+    })
+
+    mock_session = MagicMock()
+    mock_session.get = MagicMock(return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_response),
+        __aexit__=AsyncMock(return_value=False),
+    ))
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        profile = await oauth.fetch_user(p, "ghtoken")
+
+    assert profile["login"] == "bobgh"
+    assert profile["full_name"] == "Bob GitHub"
+    assert profile["avatar_url"] == "https://avatars.githubusercontent.com/u/1"
+
+
+@pytest.mark.asyncio
+async def test_fetch_user_nextcloud_nested_extraction():
+    """Nextcloud profile is nested under ocs.data; avatar is absent."""
+    p = _nextcloud_provider()
+    mock_response = AsyncMock()
+    mock_response.status = 200
+    mock_response.json = AsyncMock(return_value={
+        "ocs": {
+            "meta": {"status": "ok", "statuscode": 200},
+            "data": {
+                "id": "ncuser",
+                "display-name": "NC User",
+                "email": "nc@example.com",
+            },
+        }
+    })
+
+    mock_session = MagicMock()
+    mock_session.get = MagicMock(return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_response),
+        __aexit__=AsyncMock(return_value=False),
+    ))
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        profile = await oauth.fetch_user(p, "nctoken")
+
+    assert profile["login"] == "ncuser"
+    assert profile["full_name"] == "NC User"
+    assert profile["avatar_url"] == ""  # Nextcloud has no avatar field
+
+
+@pytest.mark.asyncio
+async def test_fetch_user_raises_on_error_status():
+    p = _gitea_provider()
+    mock_response = AsyncMock()
+    mock_response.status = 401
+    mock_response.text = AsyncMock(return_value="unauthorized")
+
+    mock_session = MagicMock()
+    mock_session.get = MagicMock(return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_response),
+        __aexit__=AsyncMock(return_value=False),
+    ))
+
+    with patch("hbd.server.oauth.aiohttp.ClientSession", return_value=AsyncMock(
+        __aenter__=AsyncMock(return_value=mock_session),
+        __aexit__=AsyncMock(return_value=False),
+    )):
+        with pytest.raises(oauth.OAuthError):
+            await oauth.fetch_user(p, "badtoken")
+
+
+def test_is_enabled_with_valid_provider():
+    assert oauth.is_enabled(CFG_ON) is True
+
+
+def test_is_enabled_false_when_no_providers():
+    assert oauth.is_enabled(CFG_OFF) is False
+
+
+def test_is_enabled_false_partial_config():
+    assert oauth.is_enabled(CFG_PARTIAL) is False