Merge branch 'main' into sampling-form

.github/workflows/main.yml

@@ -26,6 +26,10 @@ jobs:
       # - run: npm ci
       - run: npm install --no-package-lock
 
+      - name: Check linting
+        working-directory: ./client
+        run: npm run lint
+
       - name: Run client tests
         working-directory: ./client
         run: npm test

README.md

@@ -2,7 +2,7 @@
 
 The MCP inspector is a developer tool for testing and debugging MCP servers.
 
-![MCP Inspector Screenshot](mcp-inspector.png)
+![MCP Inspector Screenshot](https://raw.githubusercontent.com/modelcontextprotocol/inspector/main/mcp-inspector.png)
 
 ## Running the Inspector
 
@@ -48,12 +48,16 @@ The MCP Inspector includes a proxy server that can run and communicate with loca
 
 ### Configuration
 
-The MCP Inspector supports the following configuration settings. To change them click on the `Configuration` button in the MCP Inspector UI :
+The MCP Inspector supports the following configuration settings. To change them, click on the `Configuration` button in the MCP Inspector UI:
 
-| Name                       | Purpose                                                                                   | Default Value |
+| Setting                                 | Description                                                                                                  | Default |
-| -------------------------- | ----------------------------------------------------------------------------------------- | ------------- |
+| --------------------------------------- | ------------------------------------------------------------------------------------------------------------ | ------- |
-| MCP_SERVER_REQUEST_TIMEOUT | Maximum time in milliseconds to wait for a response from the MCP server before timing out | 10000         |
+| `MCP_SERVER_REQUEST_TIMEOUT`            | Timeout for requests to the MCP server (ms)                                                                  | 10000   |
-| MCP_PROXY_FULL_ADDRESS     | The full URL of the MCP Inspector proxy server (e.g. `http://10.2.1.14:2277`)             | `null`        |
+| `MCP_REQUEST_TIMEOUT_RESET_ON_PROGRESS` | Reset timeout on progress notifications                                                                      | true    |
+| `MCP_REQUEST_MAX_TOTAL_TIMEOUT`         | Maximum total timeout for requests sent to the MCP server (ms) (Use with progress notifications)             | 60000   |
+| `MCP_PROXY_FULL_ADDRESS`                | Set this if you are running the MCP Inspector Proxy on a non-default address. Example: http://10.1.1.22:5577 | ""      |
+
+These settings can be adjusted in real-time through the UI and will persist across sessions.
 
 ### From this repository
 

client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/inspector-client",
-  "version": "0.8.1",
+  "version": "0.8.2",
   "description": "Client-side application for the Model Context Protocol inspector",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",
@@ -23,7 +23,7 @@
     "test:watch": "jest --config jest.config.cjs --watch"
   },
   "dependencies": {
-    "@modelcontextprotocol/sdk": "^1.8.0",
+    "@modelcontextprotocol/sdk": "^1.9.0",
     "@radix-ui/react-checkbox": "^1.1.4",
     "@radix-ui/react-dialog": "^1.1.3",
     "@radix-ui/react-icons": "^1.3.0",
@@ -32,9 +32,8 @@
     "@radix-ui/react-select": "^2.1.2",
     "@radix-ui/react-slot": "^1.1.0",
     "@radix-ui/react-tabs": "^1.1.1",
-    "@radix-ui/react-tooltip": "^1.1.8",
     "@radix-ui/react-toast": "^1.2.6",
-    "@types/prismjs": "^1.26.5",
+    "@radix-ui/react-tooltip": "^1.1.8",
     "class-variance-authority": "^0.7.0",
     "clsx": "^2.1.1",
     "cmdk": "^1.0.4",
@@ -55,6 +54,7 @@
     "@testing-library/react": "^16.2.0",
     "@types/jest": "^29.5.14",
     "@types/node": "^22.7.5",
+    "@types/prismjs": "^1.26.5",
     "@types/react": "^18.3.10",
     "@types/react-dom": "^18.3.0",
     "@types/serve-handler": "^6.1.4",

client/src/App.tsx

@@ -45,10 +45,7 @@ import Sidebar from "./components/Sidebar";
 import ToolsTab from "./components/ToolsTab";
 import { DEFAULT_INSPECTOR_CONFIG } from "./lib/constants";
 import { InspectorConfig } from "./lib/configurationTypes";
-import {
+import { getMCPProxyAddress } from "./utils/configUtils";
-  getMCPProxyAddress,
-  getMCPServerRequestTimeout,
-} from "./utils/configUtils";
 import { useToast } from "@/hooks/use-toast";
 
 const params = new URLSearchParams(window.location.search);
@@ -98,10 +95,21 @@ const App = () => {
   const [config, setConfig] = useState<InspectorConfig>(() => {
     const savedConfig = localStorage.getItem(CONFIG_LOCAL_STORAGE_KEY);
     if (savedConfig) {
-      return {
+      // merge default config with saved config
+      const mergedConfig = {
         ...DEFAULT_INSPECTOR_CONFIG,
         ...JSON.parse(savedConfig),
       } as InspectorConfig;
+
+      // update description of keys to match the new description (in case of any updates to the default config description)
+      Object.entries(mergedConfig).forEach(([key, value]) => {
+        mergedConfig[key as keyof InspectorConfig] = {
+          ...value,
+          label: DEFAULT_INSPECTOR_CONFIG[key as keyof InspectorConfig].label,
+        };
+      });
+
+      return mergedConfig;
     }
     return DEFAULT_INSPECTOR_CONFIG;
   });
@@ -148,7 +156,7 @@ const App = () => {
     serverCapabilities,
     mcpClient,
     requestHistory,
-    makeRequest: makeConnectionRequest,
+    makeRequest,
     sendNotification,
     handleCompletion,
     completionsSupported,
@@ -161,8 +169,7 @@ const App = () => {
     sseUrl,
     env,
     bearerToken,
-    proxyServerUrl: getMCPProxyAddress(config),
+    config,
-    requestTimeout: getMCPServerRequestTimeout(config),
     onNotification: (notification) => {
       setNotifications((prev) => [...prev, notification as ServerNotification]);
     },
@@ -279,13 +286,13 @@ const App = () => {
     setErrors((prev) => ({ ...prev, [tabKey]: null }));
   };
 
-  const makeRequest = async <T extends z.ZodType>(
+  const sendMCPRequest = async <T extends z.ZodType>(
     request: ClientRequest,
     schema: T,
     tabKey?: keyof typeof errors,
   ) => {
     try {
-      const response = await makeConnectionRequest(request, schema);
+      const response = await makeRequest(request, schema);
       if (tabKey !== undefined) {
         clearError(tabKey);
       }
@@ -303,7 +310,7 @@ const App = () => {
   };
 
   const listResources = async () => {
-    const response = await makeRequest(
+    const response = await sendMCPRequest(
       {
         method: "resources/list" as const,
         params: nextResourceCursor ? { cursor: nextResourceCursor } : {},
@@ -316,7 +323,7 @@ const App = () => {
   };
 
   const listResourceTemplates = async () => {
-    const response = await makeRequest(
+    const response = await sendMCPRequest(
       {
         method: "resources/templates/list" as const,
         params: nextResourceTemplateCursor
@@ -333,7 +340,7 @@ const App = () => {
   };
 
   const readResource = async (uri: string) => {
-    const response = await makeRequest(
+    const response = await sendMCPRequest(
       {
         method: "resources/read" as const,
         params: { uri },
@@ -346,7 +353,7 @@ const App = () => {
 
   const subscribeToResource = async (uri: string) => {
     if (!resourceSubscriptions.has(uri)) {
-      await makeRequest(
+      await sendMCPRequest(
         {
           method: "resources/subscribe" as const,
           params: { uri },
@@ -362,7 +369,7 @@ const App = () => {
 
   const unsubscribeFromResource = async (uri: string) => {
     if (resourceSubscriptions.has(uri)) {
-      await makeRequest(
+      await sendMCPRequest(
         {
           method: "resources/unsubscribe" as const,
           params: { uri },
@@ -377,7 +384,7 @@ const App = () => {
   };
 
   const listPrompts = async () => {
-    const response = await makeRequest(
+    const response = await sendMCPRequest(
       {
         method: "prompts/list" as const,
         params: nextPromptCursor ? { cursor: nextPromptCursor } : {},
@@ -390,7 +397,7 @@ const App = () => {
   };
 
   const getPrompt = async (name: string, args: Record<string, string> = {}) => {
-    const response = await makeRequest(
+    const response = await sendMCPRequest(
       {
         method: "prompts/get" as const,
         params: { name, arguments: args },
@@ -402,7 +409,7 @@ const App = () => {
   };
 
   const listTools = async () => {
-    const response = await makeRequest(
+    const response = await sendMCPRequest(
       {
         method: "tools/list" as const,
         params: nextToolCursor ? { cursor: nextToolCursor } : {},
@@ -415,7 +422,8 @@ const App = () => {
   };
 
   const callTool = async (name: string, params: Record<string, unknown>) => {
-    const response = await makeRequest(
+    try {
+      const response = await sendMCPRequest(
         {
           method: "tools/call" as const,
           params: {
@@ -430,6 +438,18 @@ const App = () => {
         "tools",
       );
       setToolResult(response);
+    } catch (e) {
+      const toolResult: CompatibilityCallToolResult = {
+        content: [
+          {
+            type: "text",
+            text: (e as Error).message ?? String(e),
+          },
+        ],
+        isError: true,
+      };
+      setToolResult(toolResult);
+    }
   };
 
   const handleRootsChange = async () => {
@@ -437,7 +457,7 @@ const App = () => {
   };
 
   const sendLogLevelRequest = async (level: LoggingLevel) => {
-    await makeRequest(
+    await sendMCPRequest(
       {
         method: "logging/setLevel" as const,
         params: { level },
@@ -637,9 +657,10 @@ const App = () => {
                         setTools([]);
                         setNextToolCursor(undefined);
                       }}
-                      callTool={(name, params) => {
+                      callTool={async (name, params) => {
                         clearError("tools");
-                        callTool(name, params);
+                        setToolResult(null);
+                        await callTool(name, params);
                       }}
                       selectedTool={selectedTool}
                       setSelectedTool={(tool) => {
@@ -654,7 +675,7 @@ const App = () => {
                     <ConsoleTab />
                     <PingTab
                       onPingClick={() => {
-                        void makeRequest(
+                        void sendMCPRequest(
                           {
                             method: "ping" as const,
                           },

client/src/components/DynamicJsonForm.tsx

@@ -3,33 +3,9 @@ import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import JsonEditor from "./JsonEditor";
-import { updateValueAtPath, JsonObject } from "@/utils/jsonPathUtils";
+import { updateValueAtPath } from "@/utils/jsonUtils";
 import { generateDefaultValue, formatFieldLabel } from "@/utils/schemaUtils";
-
+import type { JsonValue, JsonSchemaType, JsonObject } from "@/utils/jsonUtils";
-export type JsonValue =
-  | string
-  | number
-  | boolean
-  | null
-  | undefined
-  | JsonValue[]
-  | { [key: string]: JsonValue };
-
-export type JsonSchemaType = {
-  type:
-    | "string"
-    | "number"
-    | "integer"
-    | "boolean"
-    | "array"
-    | "object"
-    | "null";
-  description?: string;
-  required?: boolean;
-  default?: JsonValue;
-  properties?: Record<string, JsonSchemaType>;
-  items?: JsonSchemaType;
-};
 
 interface DynamicJsonFormProps {
   schema: JsonSchemaType;

client/src/components/JsonView.tsx

@@ -1,9 +1,10 @@
 import { useState, memo, useMemo, useCallback, useEffect } from "react";
-import { JsonValue } from "./DynamicJsonForm";
+import type { JsonValue } from "@/utils/jsonUtils";
 import clsx from "clsx";
 import { Copy, CheckCheck } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { useToast } from "@/hooks/use-toast";
+import { getDataType, tryParseJson } from "@/utils/jsonUtils";
 
 interface JsonViewProps {
   data: unknown;
@@ -11,21 +12,7 @@ interface JsonViewProps {
   initialExpandDepth?: number;
   className?: string;
   withCopyButton?: boolean;
-}
+  isError?: boolean;
-
-function tryParseJson(str: string): { success: boolean; data: JsonValue } {
-  const trimmed = str.trim();
-  if (
-    !(trimmed.startsWith("{") && trimmed.endsWith("}")) &&
-    !(trimmed.startsWith("[") && trimmed.endsWith("]"))
-  ) {
-    return { success: false, data: str };
-  }
-  try {
-    return { success: true, data: JSON.parse(str) };
-  } catch {
-    return { success: false, data: str };
-  }
 }
 
 const JsonView = memo(
@@ -35,6 +22,7 @@ const JsonView = memo(
     initialExpandDepth = 3,
     className,
     withCopyButton = true,
+    isError = false,
   }: JsonViewProps) => {
     const { toast } = useToast();
     const [copied, setCopied] = useState(false);
@@ -100,6 +88,7 @@ const JsonView = memo(
             name={name}
             depth={0}
             initialExpandDepth={initialExpandDepth}
+            isError={isError}
           />
         </div>
       </div>
@@ -114,28 +103,28 @@ interface JsonNodeProps {
   name?: string;
   depth: number;
   initialExpandDepth: number;
+  isError?: boolean;
 }
 
 const JsonNode = memo(
-  ({ data, name, depth = 0, initialExpandDepth }: JsonNodeProps) => {
+  ({
+    data,
+    name,
+    depth = 0,
+    initialExpandDepth,
+    isError = false,
+  }: JsonNodeProps) => {
     const [isExpanded, setIsExpanded] = useState(depth < initialExpandDepth);
-
+    const [typeStyleMap] = useState<Record<string, string>>({
-    const getDataType = (value: JsonValue): string => {
-      if (Array.isArray(value)) return "array";
-      if (value === null) return "null";
-      return typeof value;
-    };
-
-    const dataType = getDataType(data);
-
-    const typeStyleMap: Record<string, string> = {
       number: "text-blue-600",
       boolean: "text-amber-600",
       null: "text-purple-600",
       undefined: "text-gray-600",
-      string: "text-green-600 break-all whitespace-pre-wrap",
+      string: "text-green-600 group-hover:text-green-500",
+      error: "text-red-600 group-hover:text-red-500",
       default: "text-gray-700",
-    };
+    });
+    const dataType = getDataType(data);
 
     const renderCollapsible = (isArray: boolean) => {
       const items = isArray
@@ -236,7 +225,14 @@ const JsonNode = memo(
                 {name}:
               </span>
             )}
-            <pre className={typeStyleMap.string}>"{value}"</pre>
+            <pre
+              className={clsx(
+                typeStyleMap.string,
+                "break-all whitespace-pre-wrap",
+              )}
+            >
+              "{value}"
+            </pre>
           </div>
         );
       }
@@ -250,8 +246,8 @@ const JsonNode = memo(
           )}
           <pre
             className={clsx(
-              typeStyleMap.string,
+              isError ? typeStyleMap.error : typeStyleMap.string,
-              "cursor-pointer group-hover:text-green-500",
+              "cursor-pointer break-all whitespace-pre-wrap",
             )}
             onClick={() => setIsExpanded(!isExpanded)}
             title={isExpanded ? "Click to collapse" : "Click to expand"}

client/src/components/ListPane.tsx

@@ -22,7 +22,7 @@ const ListPane = <T extends object>({
   isButtonDisabled,
 }: ListPaneProps<T>) => (
   <div className="bg-card rounded-lg shadow">
-    <div className="p-4 border-b border-gray-200 dark:border-gray-700">
+    <div className="p-4 border-b border-gray-200 dark:border-gray-800">
       <h3 className="font-semibold dark:text-white">{title}</h3>
     </div>
     <div className="p-4">

client/src/components/PingTab.tsx

@@ -3,7 +3,8 @@ import { Button } from "@/components/ui/button";
 
 const PingTab = ({ onPingClick }: { onPingClick: () => void }) => {
   return (
-    <TabsContent value="ping" className="grid grid-cols-2 gap-4">
+    <TabsContent value="ping">
+      <div className="grid grid-cols-2 gap-4">
         <div className="col-span-2 flex justify-center items-center">
           <Button
             onClick={onPingClick}
@@ -12,6 +13,7 @@ const PingTab = ({ onPingClick }: { onPingClick: () => void }) => {
             Ping Server
           </Button>
         </div>
+      </div>
     </TabsContent>
   );
 };

client/src/components/PromptsTab.tsx

@@ -84,7 +84,8 @@ const PromptsTab = ({
   };
 
   return (
-    <TabsContent value="prompts" className="grid grid-cols-2 gap-4">
+    <TabsContent value="prompts">
+      <div className="grid grid-cols-2 gap-4">
         <ListPane
           items={prompts}
           listItems={listPrompts}
@@ -96,7 +97,9 @@ const PromptsTab = ({
           renderItem={(prompt) => (
             <>
               <span className="flex-1">{prompt.name}</span>
-            <span className="text-sm text-gray-500">{prompt.description}</span>
+              <span className="text-sm text-gray-500">
+                {prompt.description}
+              </span>
             </>
           )}
           title="Prompts"
@@ -105,7 +108,7 @@ const PromptsTab = ({
         />
 
         <div className="bg-card rounded-lg shadow">
-        <div className="p-4 border-b border-gray-200">
+          <div className="p-4 border-b border-gray-200 dark:border-gray-800">
             <h3 className="font-semibold">
               {selectedPrompt ? selectedPrompt.name : "Select a prompt"}
             </h3>
@@ -164,6 +167,7 @@ const PromptsTab = ({
             )}
           </div>
         </div>
+      </div>
     </TabsContent>
   );
 };

client/src/components/ResourcesTab.tsx

@@ -111,7 +111,8 @@ const ResourcesTab = ({
   };
 
   return (
-    <TabsContent value="resources" className="grid grid-cols-3 gap-4">
+    <TabsContent value="resources">
+      <div className="grid grid-cols-3 gap-4">
         <ListPane
           items={resources}
           listItems={listResources}
@@ -161,7 +162,7 @@ const ResourcesTab = ({
         />
 
         <div className="bg-card rounded-lg shadow">
-        <div className="p-4 border-b border-gray-200 flex justify-between items-center">
+          <div className="p-4 border-b border-gray-200 dark:border-gray-800 flex justify-between items-center">
             <h3
               className="font-semibold truncate"
               title={selectedResource?.name || selectedTemplate?.name}
@@ -256,12 +257,14 @@ const ResourcesTab = ({
             ) : (
               <Alert>
                 <AlertDescription>
-                Select a resource or template from the list to view its contents
+                  Select a resource or template from the list to view its
+                  contents
                 </AlertDescription>
               </Alert>
             )}
           </div>
         </div>
+      </div>
     </TabsContent>
   );
 };

client/src/components/RootsTab.tsx

@@ -35,7 +35,8 @@ const RootsTab = ({
   };
 
   return (
-    <TabsContent value="roots" className="space-y-4">
+    <TabsContent value="roots">
+      <div className="space-y-4">
         <Alert>
           <AlertDescription>
             Configure the root directories that the server can access
@@ -70,6 +71,7 @@ const RootsTab = ({
             Save Changes
           </Button>
         </div>
+      </div>
     </TabsContent>
   );
 };

client/src/components/SamplingRequest.tsx

@@ -6,8 +6,9 @@ import {
   CreateMessageResultSchema,
 } from "@modelcontextprotocol/sdk/types.js";
 import { PendingRequest } from "./SamplingTab";
-import DynamicJsonForm, { JsonSchemaType, JsonValue } from "./DynamicJsonForm";
+import DynamicJsonForm from "./DynamicJsonForm";
 import { useToast } from "@/hooks/use-toast";
+import { JsonSchemaType, JsonValue } from "@/utils/jsonUtils";
 
 export type SamplingRequestProps = {
   request: PendingRequest;
@@ -23,7 +24,7 @@ const SamplingRequest = ({
   const { toast } = useToast();
 
   const [messageResult, setMessageResult] = useState<JsonValue>({
-    model: "GPT-4o",
+    model: "stub-model",
     stopReason: "endTurn",
     role: "assistant",
     content: {
@@ -32,8 +33,14 @@ const SamplingRequest = ({
     },
   });
 
-  const s = useMemo(() => {
+  const contentType = (
-    const schema: JsonSchemaType = {
+    (messageResult as { [key: string]: JsonValue })?.content as {
+      [key: string]: JsonValue;
+    }
+  )?.type;
+
+  const schema = useMemo(() => {
+    const s: JsonSchemaType = {
       type: "object",
       description: "Message result",
       properties: {
@@ -65,10 +72,9 @@ const SamplingRequest = ({
       },
     };
 
-    const contentType = (messageResult as any)?.content?.type;
+    if (contentType === "text" && s.properties) {
-    if (contentType === "text" && schema.properties) {
+      s.properties.content.properties = {
-      schema.properties.content.properties = {
+        ...s.properties.content.properties,
-        ...schema.properties.content.properties,
         text: {
           type: "string",
           default: "",
@@ -82,9 +88,9 @@ const SamplingRequest = ({
           text: "",
         },
       }));
-    } else if (contentType === "image" && schema.properties) {
+    } else if (contentType === "image" && s.properties) {
-      schema.properties.content.properties = {
+      s.properties.content.properties = {
-        ...schema.properties.content.properties,
+        ...s.properties.content.properties,
         data: {
           type: "string",
           default: "",
@@ -106,8 +112,8 @@ const SamplingRequest = ({
       }));
     }
 
-    return schema;
+    return s;
-  }, [(messageResult as any)?.content?.type]);
+  }, [contentType]);
 
   const handleApprove = (id: number) => {
     const validationResult = CreateMessageResultSchema.safeParse(messageResult);
@@ -135,7 +141,7 @@ const SamplingRequest = ({
         <div className="space-y-2">
           <DynamicJsonForm
             defaultIsJsonMode={true}
-            schema={s}
+            schema={schema}
             value={messageResult}
             onChange={(newValue: JsonValue) => {
               setMessageResult(newValue);

client/src/components/SamplingTab.tsx

@@ -19,7 +19,8 @@ export type Props = {
 
 const SamplingTab = ({ pendingRequests, onApprove, onReject }: Props) => {
   return (
-    <TabsContent value="sampling" className="mh-96">
+    <TabsContent value="sampling">
+      <div className="h-96">
         <Alert>
           <AlertDescription>
             When the server requests LLM sampling, requests will appear here for
@@ -40,6 +41,7 @@ const SamplingTab = ({ pendingRequests, onApprove, onReject }: Props) => {
             <p className="text-gray-500">No pending requests</p>
           )}
         </div>
+      </div>
     </TabsContent>
   );
 };

client/src/components/Sidebar.tsx

@@ -92,7 +92,7 @@ const Sidebar = ({
 
   return (
     <div className="w-80 bg-card border-r border-border flex flex-col h-full">
-      <div className="flex items-center justify-between p-4 border-b border-gray-200">
+      <div className="flex items-center justify-between p-4 border-b border-gray-200 dark:border-gray-800">
         <div className="flex items-center">
           <h1 className="ml-2 text-lg font-semibold">
             MCP Inspector v{version}
@@ -103,14 +103,19 @@ const Sidebar = ({
       <div className="p-4 flex-1 overflow-auto">
         <div className="space-y-4">
           <div className="space-y-2">
-            <label className="text-sm font-medium">Transport Type</label>
+            <label
+              className="text-sm font-medium"
+              htmlFor="transport-type-select"
+            >
+              Transport Type
+            </label>
             <Select
               value={transportType}
               onValueChange={(value: "stdio" | "sse") =>
                 setTransportType(value)
               }
             >
-              <SelectTrigger>
+              <SelectTrigger id="transport-type-select">
                 <SelectValue placeholder="Select transport type" />
               </SelectTrigger>
               <SelectContent>
@@ -123,8 +128,11 @@ const Sidebar = ({
           {transportType === "stdio" ? (
             <>
               <div className="space-y-2">
-                <label className="text-sm font-medium">Command</label>
+                <label className="text-sm font-medium" htmlFor="command-input">
+                  Command
+                </label>
                 <Input
+                  id="command-input"
                   placeholder="Command"
                   value={command}
                   onChange={(e) => setCommand(e.target.value)}
@@ -132,8 +140,14 @@ const Sidebar = ({
                 />
               </div>
               <div className="space-y-2">
-                <label className="text-sm font-medium">Arguments</label>
+                <label
+                  className="text-sm font-medium"
+                  htmlFor="arguments-input"
+                >
+                  Arguments
+                </label>
                 <Input
+                  id="arguments-input"
                   placeholder="Arguments (space-separated)"
                   value={args}
                   onChange={(e) => setArgs(e.target.value)}
@@ -144,8 +158,11 @@ const Sidebar = ({
           ) : (
             <>
               <div className="space-y-2">
-                <label className="text-sm font-medium">URL</label>
+                <label className="text-sm font-medium" htmlFor="sse-url-input">
+                  URL
+                </label>
                 <Input
+                  id="sse-url-input"
                   placeholder="URL"
                   value={sseUrl}
                   onChange={(e) => setSseUrl(e.target.value)}
@@ -157,6 +174,7 @@ const Sidebar = ({
                   variant="outline"
                   onClick={() => setShowBearerToken(!showBearerToken)}
                   className="flex items-center w-full"
+                  aria-expanded={showBearerToken}
                 >
                   {showBearerToken ? (
                     <ChevronDown className="w-4 h-4 mr-2" />
@@ -167,8 +185,14 @@ const Sidebar = ({
                 </Button>
                 {showBearerToken && (
                   <div className="space-y-2">
-                    <label className="text-sm font-medium">Bearer Token</label>
+                    <label
+                      className="text-sm font-medium"
+                      htmlFor="bearer-token-input"
+                    >
+                      Bearer Token
+                    </label>
                     <Input
+                      id="bearer-token-input"
                       placeholder="Bearer Token"
                       value={bearerToken}
                       onChange={(e) => setBearerToken(e.target.value)}
@@ -187,6 +211,7 @@ const Sidebar = ({
                 onClick={() => setShowEnvVars(!showEnvVars)}
                 className="flex items-center w-full"
                 data-testid="env-vars-button"
+                aria-expanded={showEnvVars}
               >
                 {showEnvVars ? (
                   <ChevronDown className="w-4 h-4 mr-2" />
@@ -201,6 +226,7 @@ const Sidebar = ({
                     <div key={idx} className="space-y-2 pb-4">
                       <div className="flex gap-2">
                         <Input
+                          aria-label={`Environment variable key ${idx + 1}`}
                           placeholder="Key"
                           value={key}
                           onChange={(e) => {
@@ -243,6 +269,7 @@ const Sidebar = ({
                       </div>
                       <div className="flex gap-2">
                         <Input
+                          aria-label={`Environment variable value ${idx + 1}`}
                           type={shownEnvVars.has(key) ? "text" : "password"}
                           placeholder="Value"
                           value={value}
@@ -309,6 +336,7 @@ const Sidebar = ({
               onClick={() => setShowConfig(!showConfig)}
               className="flex items-center w-full"
               data-testid="config-button"
+              aria-expanded={showConfig}
             >
               {showConfig ? (
                 <ChevronDown className="w-4 h-4 mr-2" />
@@ -325,8 +353,11 @@ const Sidebar = ({
                   return (
                     <div key={key} className="space-y-2">
                       <div className="flex items-center gap-1">
-                        <label className="text-sm font-medium text-green-600">
+                        <label
-                          {configKey}
+                          className="text-sm font-medium text-green-600 break-all"
+                          htmlFor={`${configKey}-input`}
+                        >
+                          {configItem.label}
                         </label>
                         <Tooltip>
                           <TooltipTrigger asChild>
@@ -339,6 +370,7 @@ const Sidebar = ({
                       </div>
                       {typeof configItem.value === "number" ? (
                         <Input
+                          id={`${configKey}-input`}
                           type="number"
                           data-testid={`${configKey}-input`}
                           value={configItem.value}
@@ -365,7 +397,7 @@ const Sidebar = ({
                             setConfig(newConfig);
                           }}
                         >
-                          <SelectTrigger>
+                          <SelectTrigger id={`${configKey}-input`}>
                             <SelectValue />
                           </SelectTrigger>
                           <SelectContent>
@@ -375,6 +407,7 @@ const Sidebar = ({
                         </Select>
                       ) : (
                         <Input
+                          id={`${configKey}-input`}
                           data-testid={`${configKey}-input`}
                           value={configItem.value}
                           onChange={(e) => {
@@ -398,7 +431,13 @@ const Sidebar = ({
           <div className="space-y-2">
             {connectionStatus === "connected" && (
               <div className="grid grid-cols-2 gap-4">
-                <Button data-testid="connect-button" onClick={onConnect}>
+                <Button
+                  data-testid="connect-button"
+                  onClick={() => {
+                    onDisconnect();
+                    onConnect();
+                  }}
+                >
                   <RotateCcw className="w-4 h-4 mr-2" />
                   {transportType === "stdio" ? "Restart" : "Reconnect"}
                 </Button>
@@ -448,14 +487,19 @@ const Sidebar = ({
 
             {loggingSupported && connectionStatus === "connected" && (
               <div className="space-y-2">
-                <label className="text-sm font-medium">Logging Level</label>
+                <label
+                  className="text-sm font-medium"
+                  htmlFor="logging-level-select"
+                >
+                  Logging Level
+                </label>
                 <Select
                   value={logLevel}
                   onValueChange={(value: LoggingLevel) =>
                     sendLogLevelRequest(value)
                   }
                 >
-                  <SelectTrigger>
+                  <SelectTrigger id="logging-level-select">
                     <SelectValue placeholder="Select logging level" />
                   </SelectTrigger>
                   <SelectContent>

client/src/components/ToolsTab.tsx

@@ -5,7 +5,8 @@ import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { TabsContent } from "@/components/ui/tabs";
 import { Textarea } from "@/components/ui/textarea";
-import DynamicJsonForm, { JsonSchemaType, JsonValue } from "./DynamicJsonForm";
+import DynamicJsonForm from "./DynamicJsonForm";
+import type { JsonValue, JsonSchemaType } from "@/utils/jsonUtils";
 import { generateDefaultValue } from "@/utils/schemaUtils";
 import {
   CallToolResultSchema,
@@ -13,7 +14,7 @@ import {
   ListToolsResult,
   Tool,
 } from "@modelcontextprotocol/sdk/types.js";
-import { Send } from "lucide-react";
+import { Loader2, Send } from "lucide-react";
 import { useEffect, useState } from "react";
 import ListPane from "./ListPane";
 import JsonView from "./JsonView";
@@ -31,7 +32,7 @@ const ToolsTab = ({
   tools: Tool[];
   listTools: () => void;
   clearTools: () => void;
-  callTool: (name: string, params: Record<string, unknown>) => void;
+  callTool: (name: string, params: Record<string, unknown>) => Promise<void>;
   selectedTool: Tool | null;
   setSelectedTool: (tool: Tool | null) => void;
   toolResult: CompatibilityCallToolResult | null;
@@ -39,6 +40,8 @@ const ToolsTab = ({
   error: string | null;
 }) => {
   const [params, setParams] = useState<Record<string, unknown>>({});
+  const [isToolRunning, setIsToolRunning] = useState(false);
+
   useEffect(() => {
     setParams({});
   }, [selectedTool]);
@@ -66,11 +69,18 @@ const ToolsTab = ({
       return (
         <>
           <h4 className="font-semibold mb-2">
-            Tool Result: {isError ? "Error" : "Success"}
+            Tool Result:{" "}
+            {isError ? (
+              <span className="text-red-600 font-semibold">Error</span>
+            ) : (
+              <span className="text-green-600 font-semibold">Success</span>
+            )}
           </h4>
           {structuredResult.content.map((item, index) => (
             <div key={index} className="mb-2">
-              {item.type === "text" && <JsonView data={item.text} />}
+              {item.type === "text" && (
+                <JsonView data={item.text} isError={isError} />
+              )}
               {item.type === "image" && (
                 <img
                   src={`data:${item.mimeType};base64,${item.data}`}
@@ -106,7 +116,8 @@ const ToolsTab = ({
   };
 
   return (
-    <TabsContent value="tools" className="grid grid-cols-2 gap-4">
+    <TabsContent value="tools">
+      <div className="grid grid-cols-2 gap-4">
         <ListPane
           items={tools}
           listItems={listTools}
@@ -129,7 +140,7 @@ const ToolsTab = ({
         />
 
         <div className="bg-card rounded-lg shadow">
-        <div className="p-4 border-b border-gray-200">
+          <div className="p-4 border-b border-gray-200 dark:border-gray-800">
             <h3 className="font-semibold">
               {selectedTool ? selectedTool.name : "Select a tool"}
             </h3>
@@ -234,9 +245,28 @@ const ToolsTab = ({
                     );
                   },
                 )}
-              <Button onClick={() => callTool(selectedTool.name, params)}>
+                <Button
+                  onClick={async () => {
+                    try {
+                      setIsToolRunning(true);
+                      await callTool(selectedTool.name, params);
+                    } finally {
+                      setIsToolRunning(false);
+                    }
+                  }}
+                  disabled={isToolRunning}
+                >
+                  {isToolRunning ? (
+                    <>
+                      <Loader2 className="w-4 h-4 mr-2 animate-spin" />
+                      Running...
+                    </>
+                  ) : (
+                    <>
                       <Send className="w-4 h-4 mr-2" />
                       Run Tool
+                    </>
+                  )}
                 </Button>
                 {toolResult && renderToolResult()}
               </div>
@@ -249,6 +279,7 @@ const ToolsTab = ({
             )}
           </div>
         </div>
+      </div>
     </TabsContent>
   );
 };

client/src/components/__tests__/DynamicJsonForm.test.tsx

@@ -1,7 +1,7 @@
 import { render, screen, fireEvent } from "@testing-library/react";
 import { describe, it, expect, jest } from "@jest/globals";
 import DynamicJsonForm from "../DynamicJsonForm";
-import type { JsonSchemaType } from "../DynamicJsonForm";
+import type { JsonSchemaType } from "@/utils/jsonUtils";
 
 describe("DynamicJsonForm String Fields", () => {
   const renderForm = (props = {}) => {

client/src/components/__tests__/Sidebar.test.tsx

@@ -343,6 +343,7 @@ describe("Sidebar Environment Variables", () => {
       expect(setConfig).toHaveBeenCalledWith(
         expect.objectContaining({
           MCP_SERVER_REQUEST_TIMEOUT: {
+            label: "Request Timeout",
             description: "Timeout for requests to the MCP server (ms)",
             value: 5000,
           },
@@ -350,6 +351,56 @@ describe("Sidebar Environment Variables", () => {
       );
     });
 
+    it("should update MCP server proxy address", () => {
+      const setConfig = jest.fn();
+      renderSidebar({ config: DEFAULT_INSPECTOR_CONFIG, setConfig });
+
+      openConfigSection();
+
+      const proxyAddressInput = screen.getByTestId(
+        "MCP_PROXY_FULL_ADDRESS-input",
+      );
+      fireEvent.change(proxyAddressInput, {
+        target: { value: "http://localhost:8080" },
+      });
+
+      expect(setConfig).toHaveBeenCalledWith(
+        expect.objectContaining({
+          MCP_PROXY_FULL_ADDRESS: {
+            label: "Inspector Proxy Address",
+            description:
+              "Set this if you are running the MCP Inspector Proxy on a non-default address. Example: http://10.1.1.22:5577",
+            value: "http://localhost:8080",
+          },
+        }),
+      );
+    });
+
+    it("should update max total timeout", () => {
+      const setConfig = jest.fn();
+      renderSidebar({ config: DEFAULT_INSPECTOR_CONFIG, setConfig });
+
+      openConfigSection();
+
+      const maxTotalTimeoutInput = screen.getByTestId(
+        "MCP_REQUEST_MAX_TOTAL_TIMEOUT-input",
+      );
+      fireEvent.change(maxTotalTimeoutInput, {
+        target: { value: "10000" },
+      });
+
+      expect(setConfig).toHaveBeenCalledWith(
+        expect.objectContaining({
+          MCP_REQUEST_MAX_TOTAL_TIMEOUT: {
+            label: "Maximum Total Timeout",
+            description:
+              "Maximum total timeout for requests sent to the MCP server (ms) (Use with progress notifications)",
+            value: 10000,
+          },
+        }),
+      );
+    });
+
     it("should handle invalid timeout values entered by user", () => {
       const setConfig = jest.fn();
       renderSidebar({ config: DEFAULT_INSPECTOR_CONFIG, setConfig });
@@ -364,6 +415,7 @@ describe("Sidebar Environment Variables", () => {
       expect(setConfig).toHaveBeenCalledWith(
         expect.objectContaining({
           MCP_SERVER_REQUEST_TIMEOUT: {
+            label: "Request Timeout",
             description: "Timeout for requests to the MCP server (ms)",
             value: 0,
           },
@@ -409,6 +461,7 @@ describe("Sidebar Environment Variables", () => {
       expect(setConfig).toHaveBeenLastCalledWith(
         expect.objectContaining({
           MCP_SERVER_REQUEST_TIMEOUT: {
+            label: "Request Timeout",
             description: "Timeout for requests to the MCP server (ms)",
             value: 3000,
           },

client/src/components/__tests__/ToolsTab.test.tsx

@@ -1,4 +1,4 @@
-import { render, screen, fireEvent } from "@testing-library/react";
+import { render, screen, fireEvent, act } from "@testing-library/react";
 import { describe, it, expect, jest } from "@jest/globals";
 import "@testing-library/jest-dom";
 import ToolsTab from "../ToolsTab";
@@ -43,7 +43,7 @@ describe("ToolsTab", () => {
     tools: mockTools,
     listTools: jest.fn(),
     clearTools: jest.fn(),
-    callTool: jest.fn(),
+    callTool: jest.fn(async () => {}),
     selectedTool: null,
     setSelectedTool: jest.fn(),
     toolResult: null,
@@ -59,14 +59,16 @@ describe("ToolsTab", () => {
     );
   };
 
-  it("should reset input values when switching tools", () => {
+  it("should reset input values when switching tools", async () => {
     const { rerender } = renderToolsTab({
       selectedTool: mockTools[0],
     });
 
     // Enter a value in the first tool's input
     const input = screen.getByRole("spinbutton") as HTMLInputElement;
+    await act(async () => {
       fireEvent.change(input, { target: { value: "42" } });
+    });
     expect(input.value).toBe("42");
 
     // Switch to second tool
@@ -80,7 +82,8 @@ describe("ToolsTab", () => {
     const newInput = screen.getByRole("spinbutton") as HTMLInputElement;
     expect(newInput.value).toBe("");
   });
-  it("should handle integer type inputs", () => {
+
+  it("should handle integer type inputs", async () => {
     renderToolsTab({
       selectedTool: mockTools[1], // Use the tool with integer type
     });
@@ -93,10 +96,49 @@ describe("ToolsTab", () => {
     expect(input.value).toBe("42");
 
     const submitButton = screen.getByRole("button", { name: /run tool/i });
+    await act(async () => {
       fireEvent.click(submitButton);
+    });
 
     expect(defaultProps.callTool).toHaveBeenCalledWith(mockTools[1].name, {
       count: 42,
     });
   });
+
+  it("should disable button and change text while tool is running", async () => {
+    // Create a promise that we can resolve later
+    let resolvePromise: ((value: unknown) => void) | undefined;
+    const mockPromise = new Promise((resolve) => {
+      resolvePromise = resolve;
+    });
+
+    // Mock callTool to return our promise
+    const mockCallTool = jest.fn().mockReturnValue(mockPromise);
+
+    renderToolsTab({
+      selectedTool: mockTools[0],
+      callTool: mockCallTool,
+    });
+
+    const submitButton = screen.getByRole("button", { name: /run tool/i });
+    expect(submitButton.getAttribute("disabled")).toBeNull();
+
+    // Click the button and verify immediate state changes
+    await act(async () => {
+      fireEvent.click(submitButton);
+    });
+
+    // Verify button is disabled and text changed
+    expect(submitButton.getAttribute("disabled")).not.toBeNull();
+    expect(submitButton.textContent).toBe("Running...");
+
+    // Resolve the promise to simulate tool completion
+    await act(async () => {
+      if (resolvePromise) {
+        await resolvePromise({});
+      }
+    });
+
+    expect(submitButton.getAttribute("disabled")).toBeNull();
+  });
 });

client/src/components/__tests__/samplingRequest.test.tsx

@@ -45,7 +45,7 @@ describe("Form to handle sampling response", () => {
 
     // Assert that onApprove is called with the correct arguments
     expect(mockOnApprove).toHaveBeenCalledWith(mockRequest.id, {
-      model: "GPT-4o",
+      model: "stub-model",
       stopReason: "endTurn",
       role: "assistant",
       content: {

client/src/components/ui/button.tsx

@@ -54,4 +54,4 @@ const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
 );
 Button.displayName = "Button";
 
-export { Button, buttonVariants };
+export { Button };