diff --git a/setup.cfg b/setup.cfg
index 537fd96..b9507ab 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -24,5 +24,10 @@ install_requires =
     httpx
     rdflib
 
+[options.extras_require]
+oidc =
+    solid-oidc-client
+    flask
+
 [options.packages.find]
 where = src
diff --git a/src/solid/oidc_auth.py b/src/solid/oidc_auth.py
new file mode 100644
index 0000000..29ae88f
--- /dev/null
+++ b/src/solid/oidc_auth.py
@@ -0,0 +1,131 @@
+try:
+    from solid_oidc_client import SolidOidcClient, SolidAuthSession, MemStore
+    import flask
+except ImportError as e:
+    raise ImportError(
+        "OIDC authentication requires optional dependencies. "
+        "Install them with: pip install solid-file[oidc]"
+    ) from e
+
+import httpx
+from httpx import Response
+from multiprocessing import Process, Queue
+from urllib.parse import urlparse, parse_qs
+from typing import Dict, Optional, Tuple, Callable
+
+
+class OidcAuth:
+    """Solid-OIDC authentication using solid-oidc-client.
+
+    Args:
+        callback_server: If True (default), starts a local Flask server to
+            automatically receive the OIDC callback. If False, the user must
+            manually paste the full redirect URL after logging in.
+        callback_port: Port for the local callback server (default 8080).
+    """
+
+    OAUTH_CALLBACK_PATH = '/oauth/callback'
+
+    def __init__(self, callback_server: bool = True, callback_port: int = 8080):
+        self.callback_server = callback_server
+        self.callback_port = callback_port
+        self.callback_uri = f"http://localhost:{callback_port}{self.OAUTH_CALLBACK_PATH}"
+        self.client = httpx.Client()
+        self.session: Optional[SolidAuthSession] = None
+        self._server_process: Optional[Process] = None
+
+    @property
+    def is_login(self) -> bool:
+        return self.session is not None
+
+    def fetch(self, method: str, url: str, options: Dict) -> Response:
+        if 'headers' not in options:
+            options['headers'] = {}
+
+        if self.session:
+            auth_headers = self.session.get_auth_headers(url, method)
+            options['headers'].update(auth_headers)
+
+        return self.client.request(method, url, **options)
+
+    def login(self, idp: str) -> None:
+        """Log in to the Solid identity provider.
+
+        If callback_server=True, starts a local server to receive the OIDC
+        callback automatically. If callback_server=False, prints the login URL
+        and prompts you to paste the full redirect URL manually.
+        """
+        solid_oidc_client = SolidOidcClient(storage=MemStore())
+        solid_oidc_client.register_client(idp, [self.callback_uri])
+        login_url = solid_oidc_client.create_login_uri('/', self.callback_uri)
+
+        if self.callback_server:
+            self._login_with_server(solid_oidc_client, login_url)
+        else:
+            self._login_manual(solid_oidc_client, login_url)
+
+    def _login_with_server(self, solid_oidc_client: SolidOidcClient, login_url: str) -> None:
+        q: Queue = Queue(1)
+        process = Process(target=_run_flask_server, args=(solid_oidc_client, self.callback_uri, q))
+        self._server_process = process
+        process.start()
+
+        print(f"Please visit this URL to log in: {login_url}")
+
+        session = SolidAuthSession.deserialize(q.get())
+        self.session = session
+        self._server_process.terminate()
+        self._server_process = None
+
+    def _login_manual(self, solid_oidc_client: SolidOidcClient, login_url: str) -> None:
+        print(f"Please visit this URL to log in:\n  {login_url}")
+        print(
+            f"\nAfter logging in, you will be redirected to a URL starting with:\n"
+            f"  {self.callback_uri}\n"
+            "Please paste the full redirect URL here:"
+        )
+        redirect_url = input().strip()
+
+        parsed = urlparse(redirect_url)
+        params = parse_qs(parsed.query)
+
+        code = params.get('code', [None])[0]
+        state = params.get('state', [None])[0]
+
+        if not code or not state:
+            raise ValueError(
+                f"Could not extract 'code' and 'state' from redirect URL: {redirect_url}"
+            )
+
+        session = solid_oidc_client.finish_login(
+            code=code,
+            state=state,
+            callback_uri=self.callback_uri,
+        )
+        self.session = session
+
+
+def _run_flask_server(solid_oidc_client: SolidOidcClient, callback_uri: str, q: Queue) -> None:
+    app = flask.Flask(__name__)
+
+    callback_path = '/' + callback_uri.split('/', 3)[-1]
+
+    @app.get(callback_path)
+    def login_callback():
+        code = flask.request.args['code']
+        state = flask.request.args['state']
+
+        session = solid_oidc_client.finish_login(
+            code=code,
+            state=state,
+            callback_uri=callback_uri,
+        )
+        q.put(session.serialize())
+
+        return flask.Response(
+            f"Logged in as {session.get_web_id()}. You can close your browser now.",
+            mimetype='text/html',
+        )
+
+    port = int(callback_uri.split(':')[2].split('/')[0])
+    app.run('localhost', port)
diff --git a/src/solid/solid_api.py b/src/solid/solid_api.py
index 343875e..53b34be 100644
--- a/src/solid/solid_api.py
+++ b/src/solid/solid_api.py
@@ -81,13 +81,24 @@ def __init__(self, auth=None):
         if not auth:
             auth = Auth()
         self.auth = auth
+        # Used when auth is a callable (get_auth_headers function)
+        self._client = httpx.Client()
 
     def fetch(self, method, url, options: Dict = None) -> Response:
         if not options:
             options = {}
         # options['verify'] = False
 
-        r = self.auth.client.request(method, url, **options)
+        if callable(self.auth):
+            # auth is a get_auth_headers(url, method) -> dict function
+            if 'headers' not in options:
+                options['headers'] = {}
+            options['headers'].update(self.auth(url, method))
+            r = self._client.request(method, url, **options)
+        elif hasattr(self.auth, 'fetch'):
+            r = self.auth.fetch(method, url, options)
+        else:
+            r = self.auth.client.request(method, url, **options)
         # r= httpx.request(method, url, **options)
         r.raise_for_status()
         return r