diff --git a/src/app/(dashboard)/dashboard/cli-tools/components/ClaudeToolCard.js b/src/app/(dashboard)/dashboard/cli-tools/components/ClaudeToolCard.js
index 9268475d..7ee5ad2e 100644
--- a/src/app/(dashboard)/dashboard/cli-tools/components/ClaudeToolCard.js
+++ b/src/app/(dashboard)/dashboard/cli-tools/components/ClaudeToolCard.js
@@ -9,6 +9,16 @@ import { matchKnownEndpoint } from "./cliEndpointMatch";
 
 const CLOUD_URL = process.env.NEXT_PUBLIC_CLOUD_URL;
 
+// Context window presets. UI shows the round number; the value written is nudged
+// down 2K to stay safely under the upstream hard cap.
+const CONTEXT_OPTIONS = [
+  { label: "Default", value: "" },
+  { label: "200K", value: "198000" },
+  { label: "300K", value: "298000" },
+  { label: "500K", value: "498000" },
+  { label: "1M", value: "998000" },
+];
+
 export default function ClaudeToolCard({
   tool,
   isExpanded,
@@ -40,6 +50,7 @@ export default function ClaudeToolCard({
   const [customBaseUrl, setCustomBaseUrl] = useState("");
   const [ccFilterNaming, setCcFilterNaming] = useState(false);
   const [exaMcpEnabled, setExaMcpEnabled] = useState(false);
+  const [maxContextTokens, setMaxContextTokens] = useState("");
   const hasInitializedModels = useRef(false);
 
   const getConfigStatus = () => {
@@ -65,6 +76,11 @@ export default function ClaudeToolCard({
     }
   }, [initialStatus]);
 
+  useEffect(() => {
+    const v = claudeStatus?.settings?.env?.CLAUDE_CODE_MAX_CONTEXT_TOKENS;
+    setMaxContextTokens(v || "");
+  }, [claudeStatus?.settings?.env?.CLAUDE_CODE_MAX_CONTEXT_TOKENS]);
+
   useEffect(() => {
     if (isExpanded) {
       if (!claudeStatus) checkClaudeStatus();
@@ -163,10 +179,13 @@ export default function ClaudeToolCard({
         const targetModel = modelMappings[model.alias];
         if (targetModel && model.envKey) env[model.envKey] = targetModel;
       });
+      if (maxContextTokens) {
+        env.CLAUDE_CODE_MAX_CONTEXT_TOKENS = maxContextTokens;
+      }
       const res = await fetch("/api/cli-tools/claude-settings", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ env, exaMcpEnabled }),
+        body: JSON.stringify({ env, exaMcpEnabled, maxContextTokens }),
       });
       const data = await res.json();
       if (res.ok) {
@@ -193,6 +212,7 @@ export default function ClaudeToolCard({
         tool.defaultModels.forEach((model) => onModelMappingChange(model.alias, model.defaultValue || ""));
         setSelectedApiKey("");
         setExaMcpEnabled(false);
+        setMaxContextTokens("");
       } else {
         setMessage({ type: "error", text: data.error || "Failed to reset settings" });
       }
@@ -222,6 +242,9 @@ export default function ClaudeToolCard({
       const targetModel = modelMappings[model.alias];
       if (targetModel && model.envKey) env[model.envKey] = targetModel;
     });
+    if (maxContextTokens) {
+      env.CLAUDE_CODE_MAX_CONTEXT_TOKENS = maxContextTokens;
+    }
 
     return [
       {
@@ -345,6 +368,17 @@ export default function ClaudeToolCard({
                   </div>
                 ))}
 
+                {/* Context Window */}
+                <div className="grid grid-cols-1 gap-1.5 sm:grid-cols-[8rem_auto_1fr_auto] sm:items-center sm:gap-2">
+                  <span className="text-xs font-semibold text-text-main sm:text-right sm:text-sm">Context window</span>
+                  <span className="material-symbols-outlined hidden text-text-muted text-[14px] sm:inline">arrow_forward</span>
+                  <select value={maxContextTokens} onChange={(e) => setMaxContextTokens(e.target.value)} className="w-full min-w-0 px-2 py-2 bg-surface rounded border border-border text-xs focus:outline-none focus:ring-1 focus:ring-primary/50 sm:py-1.5">
+                    {CONTEXT_OPTIONS.map((opt) => (
+                      <option key={opt.label} value={opt.value}>{opt.label}</option>
+                    ))}
+                  </select>
+                </div>
+
                 {/* CC Filter Naming */}
                 <div className="grid grid-cols-1 gap-1.5 sm:grid-cols-[8rem_auto_1fr_auto] sm:items-center sm:gap-2">
                   <span className="text-xs font-semibold text-text-main sm:text-right sm:text-sm">Filter naming</span>
diff --git a/src/app/api/cli-tools/claude-settings/route.js b/src/app/api/cli-tools/claude-settings/route.js
index b831e395..76ba9232 100644
--- a/src/app/api/cli-tools/claude-settings/route.js
+++ b/src/app/api/cli-tools/claude-settings/route.js
@@ -123,7 +123,7 @@ export async function GET() {
 // POST - Backup old fields and write new settings
 export async function POST(request) {
   try {
-    const { env, exaMcpEnabled } = await request.json();
+    const { env, exaMcpEnabled, maxContextTokens } = await request.json();
     
     if (!env || typeof env !== "object") {
       return NextResponse.json(
@@ -166,6 +166,14 @@ export async function POST(request) {
       },
     };
 
+    // CLAUDE_CODE_MAX_CONTEXT_TOKENS — only set when a concrete value is chosen;
+    // "Default" removes the key so Claude Code falls back to the model's window.
+    if (maxContextTokens) {
+      newSettings.env.CLAUDE_CODE_MAX_CONTEXT_TOKENS = String(maxContextTokens);
+    } else {
+      delete newSettings.env.CLAUDE_CODE_MAX_CONTEXT_TOKENS;
+    }
+
     // Write new settings
     await fs.writeFile(settingsPath, JSON.stringify(newSettings, null, 2));
 
@@ -195,6 +203,7 @@ const RESET_ENV_KEYS = [
   "ANTHROPIC_DEFAULT_SONNET_MODEL",
   "ANTHROPIC_DEFAULT_HAIKU_MODEL",
   "API_TIMEOUT_MS",
+  "CLAUDE_CODE_MAX_CONTEXT_TOKENS",
 ];
 
 // DELETE - Reset settings (remove env fields)