diff --git a/lib/kalshi/auth.js b/lib/kalshi/auth.js
index 546bc07..24d9918 100644
--- a/lib/kalshi/auth.js
+++ b/lib/kalshi/auth.js
@@ -1,6 +1,7 @@
 import crypto from 'crypto';
 
-const KALSHI_API_BASE = 'https://api.elections.kalshi.com';
+const DEFAULT_KALSHI_API_BASE = 'https://api.elections.kalshi.com';
+const KALSHI_API_BASE = (process.env.KALSHI_API_BASE || DEFAULT_KALSHI_API_BASE).trim().replace(/\/+$/, '');
 
 /**
  * Signs a Kalshi API request using RSA-PSS with SHA-256.