diff --git a/docs/app.js b/docs/app.js
index 36ca032..4e4c21a 100644
--- a/docs/app.js
+++ b/docs/app.js
@@ -1,6 +1,7 @@
 async function openAIChat(apiKey, model, messages, temperature = 0.7, top_p = 1.0, extra = {}) {
   const useCustom = document.getElementById('useCustomApiBase');
-  const base = (useCustom && useCustom.checked ? (document.getElementById('apiBase')?.value?.trim()) : '') || 'https://api.openai.com/v1';
+  let base = (useCustom && useCustom.checked ? (document.getElementById('apiBase')?.value?.trim()) : '') || 'https://api.openai.com/v1';
+  if (!/\/v1\/?$/.test(base)) base = base.replace(/\/$/, '') + '/v1';
   const url = base.replace(/\/$/, '') + '/chat/completions';
   const res = await fetch(url, {
     method: 'POST',
@@ -210,6 +211,19 @@ document.addEventListener('DOMContentLoaded', () => {
       localStorage.setItem('autotemp_use_custom_api', useCustom.checked ? '1' : '0');
     });
   }
+  // Show effective base URL
+  function updateEffective(){
+    const eff = document.getElementById('apiBaseEffective');
+    if (!eff) return;
+    const useCustom = document.getElementById('useCustomApiBase');
+    let base = (useCustom && useCustom.checked ? (document.getElementById('apiBase')?.value?.trim()) : '') || 'https://api.openai.com/v1';
+    if (!/\/v1\/?$/.test(base)) base = base.replace(/\/$/, '') + '/v1';
+    eff.textContent = base.replace(/\/$/, '') + '/chat/completions';
+  }
+  const apiBaseInput = getEl('apiBase');
+  if (apiBaseInput){ apiBaseInput.addEventListener('input', updateEffective); }
+  if (useCustom){ useCustom.addEventListener('change', updateEffective); }
+  updateEffective();
   // Run state and controls
   let running = false;
   let cancelled = false;
diff --git a/docs/index.html b/docs/index.html
index 69dc0e6..4b61afa 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -31,6 +31,7 @@
                 <div class="field" id="apiBaseField" style="display:none">
                     <label for="apiBase">API Base URL</label>
                     <input id="apiBase" value="http://127.0.0.1:1234/v1" placeholder="http://127.0.0.1:1234/v1" />
+                    <div class="hint">Effective: <code id="apiBaseEffective"></code></div>
                 </div>
                 <div class="field"></div>
             </div>
diff --git a/docs/style.css b/docs/style.css
index fdbfe2c..c367474 100644
--- a/docs/style.css
+++ b/docs/style.css
@@ -56,6 +56,7 @@ pre{ white-space:pre-wrap; background:#010a06; padding:14px; border-radius:10px;
 .footer{ display:flex; align-items:center; gap:10px; opacity:.85 }
 .blink{ width:8px; height:18px; background:var(--accent); animation: blink 1s infinite }
 .glow{ text-shadow:0 0 8px rgba(0,255,156,.35) }
+.hint{ font-size:12px; color:#a5ffd6; margin-top:6px }
 @keyframes blink{ 50%{ opacity:.2 } }
 @media(max-width:720px){ .grid-2,.grid-3{ grid-template-columns:1fr } }