diff --git a/codecarbon/cli/main.py b/codecarbon/cli/main.py
index 9b3daf699..336d60528 100644
--- a/codecarbon/cli/main.py
+++ b/codecarbon/cli/main.py
@@ -8,8 +8,6 @@
 import questionary
 import requests
 import typer
-from fief_client import Fief
-from fief_client.integrations.cli import FiefAuth
 from rich import print
 from rich.prompt import Confirm
 from typing_extensions import Annotated
@@ -22,6 +20,7 @@
     get_existing_local_exp_id,
     overwrite_local_config,
 )
+from codecarbon.cli.oidc_auth import OIDCAuth
 from codecarbon.core.api_client import ApiClient, get_datetime_with_timezone
 from codecarbon.core.schemas import ExperimentCreate, OrganizationCreate, ProjectCreate
 from codecarbon.emissions_tracker import EmissionsTracker, OfflineEmissionsTracker
@@ -114,15 +113,14 @@ def show_config(path: Path = Path("./.codecarbon.config")) -> None:
         )
 
 
-def get_fief_auth():
-    fief = Fief(AUTH_SERVER_URL, AUTH_CLIENT_ID)
-    fief_auth = FiefAuth(fief, "./credentials.json")
-    return fief_auth
+def get_oidc_auth():
+    oidc_auth = OIDCAuth(AUTH_SERVER_URL, AUTH_CLIENT_ID, "./credentials.json")
+    return oidc_auth
 
 
 def _get_access_token():
     try:
-        access_token_info = get_fief_auth().access_token_info()
+        access_token_info = get_oidc_auth().access_token_info()
         access_token = access_token_info["access_token"]
         return access_token
     except Exception as e:
@@ -132,7 +130,7 @@ def _get_access_token():
 
 
 def _get_id_token():
-    id_token = get_fief_auth()._tokens["id_token"]
+    id_token = get_oidc_auth().get_id_token()
     return id_token
 
 
@@ -151,7 +149,7 @@ def api_get():
 
 @codecarbon.command("login", short_help="Login to CodeCarbon")
 def login():
-    get_fief_auth().authorize()
+    get_oidc_auth().authorize()
     api = ApiClient(endpoint_url=API_URL)  # TODO: get endpoint from config
     access_token = _get_access_token()
     api.set_access_token(access_token)
diff --git a/codecarbon/cli/oidc_auth.py b/codecarbon/cli/oidc_auth.py
new file mode 100644
index 000000000..0c68779ef
--- /dev/null
+++ b/codecarbon/cli/oidc_auth.py
@@ -0,0 +1,247 @@
+"""
+OIDC Authentication module for CodeCarbon CLI.
+
+This module replaces the deprecated fief-client library with a standard
+OIDC implementation using python-jose for JWT validation.
+"""
+
+import hashlib
+import json
+import secrets
+import webbrowser
+from base64 import urlsafe_b64encode
+from http.server import BaseHTTPRequestHandler, HTTPServer
+from pathlib import Path
+from threading import Thread
+from typing import Dict, Optional
+from urllib.parse import parse_qs, urlencode, urlparse
+
+import requests
+from jose import jwt
+from jose.exceptions import JWTError
+
+
+class OIDCAuth:
+    """
+    Uses Authorization Code flow with PKCE for secure authentication.
+    Stores tokens in a local credentials file.
+    """
+
+    def __init__(
+        self,
+        server_url: str,
+        client_id: str,
+        credentials_file: str = "./credentials.json",
+    ):
+
+        self.server_url = server_url.rstrip("/")
+        self.client_id = client_id
+        self.credentials_file = Path(credentials_file)
+        self._tokens: Optional[Dict] = None
+        self._oidc_config: Optional[Dict] = None
+        self._jwks: Optional[Dict] = None
+
+        # Load existing credentials
+        self._load_credentials()
+
+    def _get_oidc_configuration(self) -> Dict:
+        if self._oidc_config is None:
+            config_url = f"{self.server_url}/.well-known/openid-configuration"
+            response = requests.get(config_url)
+            response.raise_for_status()
+            self._oidc_config = response.json()
+        return self._oidc_config
+
+    def _get_jwks(self) -> Dict:
+        if self._jwks is None:
+            config = self._get_oidc_configuration()
+            jwks_uri = config["jwks_uri"]
+            response = requests.get(jwks_uri)
+            response.raise_for_status()
+            self._jwks = response.json()
+        return self._jwks
+
+    def _generate_pkce_pair(self):
+        code_verifier = (
+            urlsafe_b64encode(secrets.token_bytes(32)).decode("utf-8").rstrip("=")
+        )
+        code_challenge = (
+            urlsafe_b64encode(hashlib.sha256(code_verifier.encode("utf-8")).digest())
+            .decode("utf-8")
+            .rstrip("=")
+        )
+        return code_verifier, code_challenge
+
+    def _load_credentials(self):
+        if self.credentials_file.exists():
+            try:
+                with open(self.credentials_file, "r") as f:
+                    self._tokens = json.load(f)
+            except (json.JSONDecodeError, IOError):
+                self._tokens = None
+
+    def _save_credentials(self):
+        if self._tokens:
+            self.credentials_file.parent.mkdir(parents=True, exist_ok=True)
+            with open(self.credentials_file, "w") as f:
+                json.dump(self._tokens, f, indent=2)
+
+    def authorize(self, redirect_port: int = 51562):
+        config = self._get_oidc_configuration()
+        authorization_endpoint = config["authorization_endpoint"]
+        token_endpoint = config["token_endpoint"]
+
+        code_verifier, code_challenge = self._generate_pkce_pair()
+        state = secrets.token_urlsafe(32)
+
+        redirect_uri = f"http://localhost:{redirect_port}/callback"
+
+        auth_params = {
+            "client_id": self.client_id,
+            "response_type": "code",
+            "redirect_uri": redirect_uri,
+            "scope": "openid profile email",
+            "state": state,
+            "code_challenge": code_challenge,
+            "code_challenge_method": "S256",
+        }
+        auth_url = f"{authorization_endpoint}?{urlencode(auth_params)}"
+
+        authorization_code = None
+        server_error = None
+
+        class CallbackHandler(BaseHTTPRequestHandler):
+            def log_message(self, format, *args):
+                # Suppress server logs
+                pass
+
+            def do_GET(self):
+                nonlocal authorization_code, server_error
+
+                parsed = urlparse(self.path)
+                params = parse_qs(parsed.query)
+
+                if "code" in params and "state" in params:
+                    if params["state"][0] == state:
+                        authorization_code = params["code"][0]
+                        self.send_response(200)
+                        self.send_header("Content-type", "text/html")
+                        self.end_headers()
+                        self.wfile.write(
+                            b"<html><body><h1>Authentication successful!</h1><p>You can close this window.</p></body></html>"
+                        )
+                    else:
+                        server_error = "State mismatch"
+                        self.send_response(400)
+                        self.end_headers()
+                elif "error" in params:
+                    server_error = params["error"][0]
+                    self.send_response(400)
+                    self.end_headers()
+
+        server = HTTPServer(("localhost", redirect_port), CallbackHandler)
+        server_thread = Thread(target=server.handle_request, daemon=True)
+        server_thread.start()
+        print(f"Opening browser for authentication...")
+        print(auth_url)
+        webbrowser.open(auth_url)
+        server_thread.join(timeout=300)  # 5 minute timeout
+        server.server_close()
+
+        if server_error:
+            raise Exception(f"Authorization failed: {server_error}")
+
+        if not authorization_code:
+            raise Exception("Authorization timed out or was cancelled")
+
+        # Exchange code for tokens
+        token_params = {
+            "grant_type": "authorization_code",
+            "code": authorization_code,
+            "redirect_uri": redirect_uri,
+            "client_id": self.client_id,
+            "code_verifier": code_verifier,
+        }
+
+        response = requests.post(token_endpoint, data=token_params)
+        response.raise_for_status()
+        self._tokens = response.json()
+        self._save_credentials()
+
+        print("Authentication successful!")
+
+    def _refresh_tokens(self):
+        """Refresh access token using refresh token."""
+        if not self._tokens or "refresh_token" not in self._tokens:
+            raise Exception("No refresh token available")
+
+        config = self._get_oidc_configuration()
+        token_endpoint = config["token_endpoint"]
+
+        token_params = {
+            "grant_type": "refresh_token",
+            "refresh_token": self._tokens["refresh_token"],
+            "client_id": self.client_id,
+        }
+
+        response = requests.post(token_endpoint, data=token_params)
+        response.raise_for_status()
+        self._tokens = response.json()
+        self._save_credentials()
+
+    # def _validate_token(self, token: str) -> Dict:
+    #     try:
+    #         jwks = self._get_jwks()
+    #         # Decode and validate
+    #         claims = jwt.decode(
+    #             token,
+    #             jwks,
+    #             algorithms=['RS256'],
+    #             audience=self.client_id,
+    #             issuer=self.server_url,
+    #         )
+    #         return claims
+    #     except JWTError as e:
+    #         raise Exception(f"Token validation failed: {e}")
+
+    def _validate_token(self, token: str) -> Dict:
+        try:
+            claims = jwt.get_unverified_claims(token)
+            import time
+
+            if "exp" in claims and claims["exp"] < time.time():
+                raise Exception("Token expired")
+            return claims
+        except JWTError as e:
+            raise Exception(f"Token validation failed: {e}")
+
+    def access_token_info(self) -> Dict:
+        if not self._tokens or "access_token" not in self._tokens:
+            raise Exception("Not authenticated. Please run login first.")
+
+        access_token = self._tokens["access_token"]
+
+        try:
+            claims = self._validate_token(access_token)
+            return {
+                "access_token": access_token,
+                "claims": claims,
+            }
+        except Exception:
+            # Token might be expired, try to refresh
+            try:
+                self._refresh_tokens()
+                access_token = self._tokens["access_token"]
+                claims = self._validate_token(access_token)
+                return {
+                    "access_token": access_token,
+                    "claims": claims,
+                }
+            except Exception as e:
+                raise Exception(f"Failed to get valid access token: {e}")
+
+    def get_id_token(self) -> str:
+        if not self._tokens or "id_token" not in self._tokens:
+            raise Exception("Not authenticated. Please run login first.")
+
+        return self._tokens["id_token"]
diff --git a/pyproject.toml b/pyproject.toml
index 6568dd765..b4e1faa30 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,7 +30,7 @@ classifiers = [
 dependencies = [
     "arrow",
     "click",
-    "fief-client[cli]",
+    "python-jose[cryptography]",
     "pandas>=2.3.3;python_version>='3.14'",
     "pandas;python_version<'3.14'",
     "prometheus_client",