Lexoffice.login May 2026
def __init__(self, client_id, redirect_uri, scopes=None): self.client_id = client_id self.redirect_uri = redirect_uri self.scopes = scopes or ["openid", "profile", "invoice.read"] self.code_verifier = None self.state = None
import hashlib import secrets import requests from urllib.parse import urlencode, urlparse, parse_qs class LexofficeLogin: AUTH_URL = "https://login.lexoffice.io/connect/authorize" TOKEN_URL = "https://login.lexoffice.io/connect/token" lexoffice.login
lexoffice’s strength is strict PKCE enforcement and well‑structured OpenID Connect Discovery ( /.well-known/openid-configuration ). The lexoffice.login mechanism is a robust implementation of OAuth 2.0 + PKCE, suitable for both server‑side and public client applications. Developers must correctly generate the PKCE pair, validate the state parameter, and store tokens securely. By following the reference implementation and security recommendations in this paper, integration can achieve both usability and a high security level. "scope": "invoice.read contact.read openid profile"
def handle_callback(self, callback_url): """Parse callback, verify state, exchange code for tokens.""" parsed = urlparse(callback_url) query = parse_qs(parsed.query) if "state" not in query or query["state"][0] != self.state: raise ValueError("Invalid state parameter – possible CSRF attack") if "code" not in query: raise ValueError("No authorization code received") auth_code = query["code"][0] governed by the lexoffice.login process.
def _generate_pkce_pair(self): """Generate code_verifier and code_challenge (S256).""" self.code_verifier = secrets.token_urlsafe(64)[:128] code_challenge = hashlib.sha256(self.code_verifier.encode()).digest() # Base64url encode without padding code_challenge = secrets.token_urlsafe(32) # simplified; use proper base64url # For correctness, implement: import base64 code_challenge = base64.urlsafe_b64encode( hashlib.sha256(self.code_verifier.encode()).digest() ).decode().rstrip("=") return code_challenge
– lexoffice, OAuth 2.0, PKCE, API security, cloud accounting, single-page application (SPA), authentication flow. 1. Introduction lexoffice is a leading cloud accounting software for small and medium-sized enterprises (SMEs) in Germany. Its API (documented at https://developers.lexoffice.io ) enables automated invoice creation, contact management, and financial reporting. All API endpoints require authenticated access, governed by the lexoffice.login process.
"access_token": "eyJhbGciOiJSUzI1NiIs...", "token_type": "Bearer", "expires_in": 3600, "refresh_token": "8xLOxBtZp8...", "scope": "invoice.read contact.read openid profile"
