diff --git a/components/analyze/AiGate.tsx b/components/analyze/AiGate.tsx
new file mode 100644
index 0000000..5f8a321
--- /dev/null
+++ b/components/analyze/AiGate.tsx
@@ -0,0 +1,134 @@
+"use client";
+
+import { motion } from "framer-motion";
+import { Zap, Sparkles } from "lucide-react";
+import { SiGithub } from "@icons-pack/react-simple-icons";
+import { createClient } from "@/lib/supabase-browser";
+import { useCallback } from "react";
+import { AI_FREE_LIMIT } from "@/lib/ai-usage";
+
+interface AiGateProps {
+  state: "auth_required" | "limit_reached";
+  repoUrl?: string;
+}
+
+export default function AiGate({ state, repoUrl }: AiGateProps) {
+  const handleGitHubLogin = useCallback(async () => {
+    const supabase = createClient();
+    await supabase.auth.signInWithOAuth({
+      provider: "github",
+      options: {
+        scopes: "user:email",
+        redirectTo: `${window.location.origin}/analyze?repo=${encodeURIComponent(repoUrl ?? "")}`,
+      },
+    });
+  }, [repoUrl]);
+
+  return (
+    <motion.div
+      initial={{ opacity: 0 }}
+      animate={{ opacity: 1 }}
+      className="absolute inset-0 z-30 flex items-center justify-center"
+    >
+      {/* Blurred backdrop */}
+      <div className="absolute inset-0 backdrop-blur-md bg-[#0a0a0a]/60" />
+
+      {/* Card */}
+      <motion.div
+        initial={{ opacity: 0, scale: 0.95, y: 10 }}
+        animate={{ opacity: 1, scale: 1, y: 0 }}
+        transition={{
+          type: "spring",
+          stiffness: 340,
+          damping: 28,
+          delay: 0.05,
+        }}
+        className="relative z-10 w-full max-w-sm mx-4 bg-[#111]/90 border border-white/10 rounded-2xl p-6 shadow-[0_0_60px_rgba(0,0,0,0.6)] flex flex-col items-center gap-5 text-center"
+      >
+        {state === "auth_required" ? (
+          <>
+            {/* Icon */}
+            <div className="w-12 h-12 rounded-xl bg-white/5 border border-white/10 flex items-center justify-center">
+              <SiGithub className="w-5 h-5 text-slate-300" />
+            </div>
+
+            {/* Copy */}
+            <div className="flex flex-col gap-1.5">
+              <h3 className="text-base font-bold text-white tracking-tight">
+                Unlock AI Insights
+              </h3>
+              <p className="text-xs text-slate-400 leading-relaxed">
+                Get {AI_FREE_LIMIT} free AI architectural analyses. Sign in with
+                GitHub — no credit card needed.
+              </p>
+            </div>
+
+            {/* Feature pills */}
+            <div className="flex flex-wrap justify-center gap-2">
+              {[
+                "Architecture Summary",
+                "Risk Detection",
+                "Code Health Score",
+              ].map((f) => (
+                <span
+                  key={f}
+                  className="text-[10px] font-mono px-2.5 py-1 rounded-full bg-white/5 border border-white/10 text-slate-400"
+                >
+                  {f}
+                </span>
+              ))}
+            </div>
+
+            {/* CTA */}
+            <button
+              onClick={handleGitHubLogin}
+              className="w-full flex items-center justify-center gap-2.5 py-3 px-4 rounded-xl bg-white text-black font-bold text-sm hover:bg-slate-100 transition-colors shadow-lg"
+            >
+              <SiGithub className="w-4 h-4" />
+              Continue with GitHub
+            </button>
+
+            <p className="text-[10px] text-slate-600 font-mono">
+              Free forever · No spam · Open source
+            </p>
+          </>
+        ) : (
+          <>
+            {/* Icon */}
+            <div className="w-12 h-12 rounded-xl bg-amber-500/10 border border-amber-500/20 flex items-center justify-center">
+              <Zap className="w-5 h-5 text-amber-400" />
+            </div>
+
+            {/* Copy */}
+            <div className="flex flex-col gap-1.5">
+              <h3 className="text-base font-bold text-white tracking-tight">
+                You&apos;ve used your {AI_FREE_LIMIT} free analyses
+              </h3>
+              <p className="text-xs text-slate-400 leading-relaxed">
+                Upgrade to Pro for unlimited AI insights, or plug in your own
+                Gemini API key to keep going for free.
+              </p>
+            </div>
+
+            {/* CTA — Pro (placeholder) */}
+            <button
+              disabled
+              className="w-full flex items-center justify-center gap-2.5 py-3 px-4 rounded-xl bg-gradient-to-r from-amber-500 to-orange-500 text-black font-bold text-sm opacity-80 cursor-not-allowed"
+            >
+              <Sparkles className="w-4 h-4" />
+              Upgrade to Pro — Coming Soon
+            </button>
+
+            {/* CTA — Own key (placeholder) */}
+            <button
+              disabled
+              className="w-full flex items-center justify-center gap-2 py-2.5 px-4 rounded-xl border border-white/10 text-slate-400 text-xs font-mono hover:border-white/20 transition-colors cursor-not-allowed"
+            >
+              Use my own API key — Coming Soon
+            </button>
+          </>
+        )}
+      </motion.div>
+    </motion.div>
+  );
+}
diff --git a/components/analyze/DoctorPanel.tsx b/components/analyze/DoctorPanel.tsx
index 4a9c756..b3c908f 100644
--- a/components/analyze/DoctorPanel.tsx
+++ b/components/analyze/DoctorPanel.tsx
@@ -1,33 +1,54 @@
 "use client";
 
 import { motion } from "framer-motion";
+
 import { Terminal, MessageSquare } from "lucide-react";
+
 import dynamic from "next/dynamic";
+
 import { ErrorBoundary } from "@/components/ui/ErrorBoundary";
+
 import { RepoData } from "@/lib/types/analyze";
+
 import SkeletonLoader from "@/components/analyze/SkeletonLoader";
 
+import AiGate from "@/components/analyze/AiGate";
+
 const DebugInterface = dynamic(
   () => import("@/components/debug/DebugInterface"),
+
   { loading: () => <SkeletonLoader />, ssr: false },
 );
 
 interface DoctorPanelProps {
   data: RepoData;
+
   source: string | null;
+
   onOpenChat: () => void;
+
+  aiGateState: "free" | "login-required" | "limit-reached" | null;
 }
 
 export default function DoctorPanel({
   data,
+
   source,
+
   onOpenChat,
+
+  aiGateState,
 }: DoctorPanelProps) {
   const repoUrl =
     source === "local"
       ? "Local.zip Codebase"
       : `https://github.com/${data.owner}/${data.repo}`;
 
+  const githubRepoUrl =
+    source === "local"
+      ? undefined
+      : `https://github.com/${data.owner}/${data.repo}`;
+
   return (
     <motion.div
       key="doctor"
@@ -43,17 +64,37 @@ export default function DoctorPanel({
       <div className="flex flex-col gap-4 h-full">
         {data.mermaidDiagram ? (
           <>
+            {/* Wrap the AI panel in a relative container so AiGate
+
+                can position itself absolutely over it */}
+
             <div className="w-full flex-1 min-h-0 rounded-2xl border border-white/5 overflow-hidden bg-[#0e0e0e] relative">
               <ErrorBoundary fallbackMessage="Diagnostic interface crashed.">
                 <DebugInterface repoUrl={repoUrl} />
               </ErrorBoundary>
+
+              {/* Gate overlay — renders on top when active */}
+
+              {(aiGateState === "login-required" ||
+                aiGateState === "limit-reached") && (
+                <AiGate
+                  state={
+                    aiGateState === "login-required"
+                      ? "auth_required"
+                      : "limit_reached"
+                  }
+                  repoUrl={githubRepoUrl}
+                />
+              )}
             </div>
+
             <motion.button
               whileTap={{ scale: 0.99 }}
               onClick={onOpenChat}
               className="w-full flex-shrink-0 py-4 rounded-xl bg-white/5 hover:bg-white/10 border border-white/10 transition-all flex items-center justify-center gap-3 group shadow-lg"
             >
               <MessageSquare className="w-5 h-5 text-slate-400 group-hover:text-white transition-colors" />
+
               <span className="text-sm font-bold text-slate-300 group-hover:text-white transition-colors">
                 Discuss this diagnosis in Copilot &rarr;
               </span>
@@ -62,6 +103,7 @@ export default function DoctorPanel({
         ) : (
           <div className="w-full h-full rounded-2xl border border-white/5 bg-[#0e0e0e] flex flex-col items-center justify-center min-h-[600px] p-4 text-center">
             <Terminal className="w-10 h-10 text-slate-600 mb-4" />
+
             <p className="text-slate-500 font-mono text-xs">
               Diagnostic core offline.
             </p>