Merge branch 'main' of https://github.com/modelcontextprotocol/inspector

.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
@@ -54,8 +58,6 @@ jobs:
       # - run: npm ci
       - run: npm install --no-package-lock
 
-      - run: npm run build
-
       # TODO: Add --provenance once the repo is public
       - run: npm run publish-all
         env:

cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/inspector-cli",
-  "version": "0.10.2",
+  "version": "0.11.0",
   "description": "CLI for the Model Context Protocol inspector",
   "license": "MIT",
   "author": "Anthropic, PBC (https://anthropic.com)",
@@ -21,7 +21,7 @@
   },
   "devDependencies": {},
   "dependencies": {
-    "@modelcontextprotocol/sdk": "^1.10.0",
+    "@modelcontextprotocol/sdk": "^1.11.0",
     "commander": "^13.1.0",
     "spawn-rx": "^5.1.2"
   }

client/bin/client.js

@@ -9,10 +9,34 @@ const __dirname = dirname(fileURLToPath(import.meta.url));
 const distPath = join(__dirname, "../dist");
 
 const server = http.createServer((request, response) => {
-  return handler(request, response, {
+  const handlerOptions = {
     public: distPath,
     rewrites: [{ source: "/**", destination: "/index.html" }],
-  });
+    headers: [
+      {
+        // Ensure index.html is never cached
+        source: "index.html",
+        headers: [
+          {
+            key: "Cache-Control",
+            value: "no-cache, no-store, max-age=0",
+          },
+        ],
+      },
+      {
+        // Allow long-term caching for hashed assets
+        source: "assets/**",
+        headers: [
+          {
+            key: "Cache-Control",
+            value: "public, max-age=31536000, immutable",
+          },
+        ],
+      },
+    ],
+  };
+
+  return handler(request, response, handlerOptions);
 });
 
 const port = process.env.PORT || 6274;

client/jest.config.cjs

@@ -1,6 +1,6 @@
 module.exports = {
   preset: "ts-jest",
-  testEnvironment: "jsdom",
+  testEnvironment: "jest-fixed-jsdom",
   moduleNameMapper: {
     "^@/(.*)$": "<rootDir>/src/$1",
     "\\.css$": "<rootDir>/src/__mocks__/styleMock.js",

client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/inspector-client",
-  "version": "0.10.2",
+  "version": "0.11.0",
   "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": "^1.10.0",
+    "@modelcontextprotocol/sdk": "^1.11.0",
     "@radix-ui/react-checkbox": "^1.1.4",
     "@radix-ui/react-dialog": "^1.1.3",
     "@radix-ui/react-icons": "^1.3.0",

client/src/App.tsx

@@ -81,9 +81,14 @@ const App = () => {
   const [sseUrl, setSseUrl] = useState<string>(() => {
     return localStorage.getItem("lastSseUrl") || "http://localhost:3001/sse";
   });
-  const [transportType, setTransportType] = useState<"stdio" | "sse">(() => {
+  const [transportType, setTransportType] = useState<
+    "stdio" | "sse" | "streamable-http"
+  >(() => {
     return (
-      (localStorage.getItem("lastTransportType") as "stdio" | "sse") || "stdio"
+      (localStorage.getItem("lastTransportType") as
+        | "stdio"
+        | "sse"
+        | "streamable-http") || "stdio"
     );
   });
   const [logLevel, setLogLevel] = useState<LoggingLevel>("debug");
@@ -642,6 +647,7 @@ const App = () => {
                       setSelectedPrompt={(prompt) => {
                         clearError("prompts");
                         setSelectedPrompt(prompt);
+                        setPromptContent("");
                       }}
                       handleCompletion={handleCompletion}
                       completionsSupported={completionsSupported}

client/src/components/DynamicJsonForm.tsx

@@ -250,7 +250,12 @@ const DynamicJsonForm = ({
     <div className="space-y-4">
       <div className="flex justify-end space-x-2">
         {isJsonMode && (
-          <Button variant="outline" size="sm" onClick={formatJson}>
+          <Button
+            type="button"
+            variant="outline"
+            size="sm"
+            onClick={formatJson}
+          >
             Format JSON
           </Button>
         )}

client/src/components/JsonView.tsx

@@ -3,7 +3,7 @@ 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 { useToast } from "@/lib/hooks/useToast";
 import { getDataType, tryParseJson } from "@/utils/jsonUtils";
 
 interface JsonViewProps {

client/src/components/OAuthCallback.tsx

@@ -2,7 +2,7 @@ import { useEffect, useRef } from "react";
 import { InspectorOAuthClientProvider } from "../lib/auth";
 import { SESSION_KEYS } from "../lib/constants";
 import { auth } from "@modelcontextprotocol/sdk/client/auth.js";
-import { useToast } from "@/hooks/use-toast.ts";
+import { useToast } from "@/lib/hooks/useToast";
 import {
   generateOAuthErrorDescription,
   parseOAuthCallbackParams,

client/src/components/SamplingRequest.tsx

@@ -0,0 +1,167 @@
+import { Button } from "@/components/ui/button";
+import JsonView from "./JsonView";
+import { useMemo, useState } from "react";
+import {
+  CreateMessageResult,
+  CreateMessageResultSchema,
+} from "@modelcontextprotocol/sdk/types.js";
+import { PendingRequest } from "./SamplingTab";
+import DynamicJsonForm from "./DynamicJsonForm";
+import { useToast } from "@/lib/hooks/useToast";
+import { JsonSchemaType, JsonValue } from "@/utils/jsonUtils";
+
+export type SamplingRequestProps = {
+  request: PendingRequest;
+  onApprove: (id: number, result: CreateMessageResult) => void;
+  onReject: (id: number) => void;
+};
+
+const SamplingRequest = ({
+  onApprove,
+  request,
+  onReject,
+}: SamplingRequestProps) => {
+  const { toast } = useToast();
+
+  const [messageResult, setMessageResult] = useState<JsonValue>({
+    model: "stub-model",
+    stopReason: "endTurn",
+    role: "assistant",
+    content: {
+      type: "text",
+      text: "",
+    },
+  });
+
+  const contentType = (
+    (messageResult as { [key: string]: JsonValue })?.content as {
+      [key: string]: JsonValue;
+    }
+  )?.type;
+
+  const schema = useMemo(() => {
+    const s: JsonSchemaType = {
+      type: "object",
+      description: "Message result",
+      properties: {
+        model: {
+          type: "string",
+          default: "stub-model",
+          description: "model name",
+        },
+        stopReason: {
+          type: "string",
+          default: "endTurn",
+          description: "Stop reason",
+        },
+        role: {
+          type: "string",
+          default: "endTurn",
+          description: "Role of the model",
+        },
+        content: {
+          type: "object",
+          properties: {
+            type: {
+              type: "string",
+              default: "text",
+              description: "Type of content",
+            },
+          },
+        },
+      },
+    };
+
+    if (contentType === "text" && s.properties) {
+      s.properties.content.properties = {
+        ...s.properties.content.properties,
+        text: {
+          type: "string",
+          default: "",
+          description: "text content",
+        },
+      };
+      setMessageResult((prev) => ({
+        ...(prev as { [key: string]: JsonValue }),
+        content: {
+          type: contentType,
+          text: "",
+        },
+      }));
+    } else if (contentType === "image" && s.properties) {
+      s.properties.content.properties = {
+        ...s.properties.content.properties,
+        data: {
+          type: "string",
+          default: "",
+          description: "Base64 encoded image data",
+        },
+        mimeType: {
+          type: "string",
+          default: "",
+          description: "Mime type of the image",
+        },
+      };
+      setMessageResult((prev) => ({
+        ...(prev as { [key: string]: JsonValue }),
+        content: {
+          type: contentType,
+          data: "",
+          mimeType: "",
+        },
+      }));
+    }
+
+    return s;
+  }, [contentType]);
+
+  const handleApprove = (id: number) => {
+    const validationResult = CreateMessageResultSchema.safeParse(messageResult);
+    if (!validationResult.success) {
+      toast({
+        title: "Error",
+        description: `There was an error validating the message result: ${validationResult.error.message}`,
+        variant: "destructive",
+      });
+      return;
+    }
+
+    onApprove(id, validationResult.data);
+  };
+
+  return (
+    <div
+      data-testid="sampling-request"
+      className="flex gap-4 p-4 border rounded-lg space-y-4"
+    >
+      <div className="flex-1 bg-gray-50 dark:bg-gray-800 dark:text-gray-100 p-2 rounded">
+        <JsonView data={JSON.stringify(request.request)} />
+      </div>
+      <form className="flex-1 space-y-4">
+        <div className="space-y-2">
+          <DynamicJsonForm
+            schema={schema}
+            value={messageResult}
+            onChange={(newValue: JsonValue) => {
+              setMessageResult(newValue);
+            }}
+          />
+        </div>
+        <div className="flex space-x-2 mt-1">
+          <Button type="button" onClick={() => handleApprove(request.id)}>
+            Approve
+          </Button>
+          <Button
+            type="button"
+            variant="outline"
+            onClick={() => onReject(request.id)}
+          >
+            Reject
+          </Button>
+        </div>
+      </form>
+    </div>
+  );
+};
+
+export default SamplingRequest;

client/src/components/SamplingTab.tsx

@@ -1,11 +1,10 @@
 import { Alert, AlertDescription } from "@/components/ui/alert";
-import { Button } from "@/components/ui/button";
 import { TabsContent } from "@/components/ui/tabs";
 import {
   CreateMessageRequest,
   CreateMessageResult,
 } from "@modelcontextprotocol/sdk/types.js";
-import JsonView from "./JsonView";
+import SamplingRequest from "./SamplingRequest";
 
 export type PendingRequest = {
   id: number;
@@ -19,19 +18,6 @@ export type Props = {
 };
 
 const SamplingTab = ({ pendingRequests, onApprove, onReject }: Props) => {
-  const handleApprove = (id: number) => {
-    // For now, just return a stub response
-    onApprove(id, {
-      model: "stub-model",
-      stopReason: "endTurn",
-      role: "assistant",
-      content: {
-        type: "text",
-        text: "This is a stub response.",
-      },
-    });
-  };
-
   return (
     <TabsContent value="sampling">
       <div className="h-96">
@@ -44,21 +30,12 @@ const SamplingTab = ({ pendingRequests, onApprove, onReject }: Props) => {
         <div className="mt-4 space-y-4">
           <h3 className="text-lg font-semibold">Recent Requests</h3>
           {pendingRequests.map((request) => (
-            <div key={request.id} className="p-4 border rounded-lg space-y-4">
+            <SamplingRequest
-              <JsonView
+              key={request.id}
-                className="bg-gray-50 dark:bg-gray-800 dark:text-gray-100 rounded"
+              request={request}
-                data={JSON.stringify(request.request)}
+              onApprove={onApprove}
-              />
+              onReject={onReject}
-
+            />
-              <div className="flex space-x-2">
-                <Button onClick={() => handleApprove(request.id)}>
-                  Approve
-                </Button>
-                <Button variant="outline" onClick={() => onReject(request.id)}>
-                  Reject
-                </Button>
-              </div>
-            </div>
           ))}
           {pendingRequests.length === 0 && (
             <p className="text-gray-500">No pending requests</p>

client/src/components/Sidebar.tsx

@@ -31,7 +31,7 @@ import {
 } from "@modelcontextprotocol/sdk/types.js";
 import { InspectorConfig } from "@/lib/configurationTypes";
 import { ConnectionStatus } from "@/lib/constants";
-import useTheme from "../lib/useTheme";
+import useTheme from "../lib/hooks/useTheme";
 import { version } from "../../../package.json";
 import {
   Tooltip,
@@ -42,8 +42,8 @@ import { useToast } from "@/hooks/use-toast";
 
 interface SidebarProps {
   connectionStatus: ConnectionStatus;
-  transportType: "stdio" | "sse";
+  transportType: "stdio" | "sse" | "streamable-http";
-  setTransportType: (type: "stdio" | "sse") => void;
+  setTransportType: (type: "stdio" | "sse" | "streamable-http") => void;
   command: string;
   setCommand: (command: string) => void;
   args: string;
@@ -229,7 +229,7 @@ const Sidebar = ({
             </label>
             <Select
               value={transportType}
-              onValueChange={(value: "stdio" | "sse") =>
+              onValueChange={(value: "stdio" | "sse" | "streamable-http") =>
                 setTransportType(value)
               }
             >
@@ -239,6 +239,7 @@ const Sidebar = ({
               <SelectContent>
                 <SelectItem value="stdio">STDIO</SelectItem>
                 <SelectItem value="sse">SSE</SelectItem>
+                <SelectItem value="streamable-http">Streamable HTTP</SelectItem>
               </SelectContent>
             </Select>
           </div>

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

@@ -7,7 +7,7 @@ import { InspectorConfig } from "@/lib/configurationTypes";
 import { TooltipProvider } from "@/components/ui/tooltip";
 
 // Mock theme hook
-jest.mock("../../lib/useTheme", () => ({
+jest.mock("../../lib/hooks/useTheme", () => ({
   __esModule: true,
   default: () => ["light", jest.fn()],
 }));

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

@@ -0,0 +1,73 @@
+import { render, screen, fireEvent } from "@testing-library/react";
+import SamplingRequest from "../SamplingRequest";
+import { PendingRequest } from "../SamplingTab";
+
+const mockRequest: PendingRequest = {
+  id: 1,
+  request: {
+    method: "sampling/createMessage",
+    params: {
+      messages: [
+        {
+          role: "user",
+          content: {
+            type: "text",
+            text: "What files are in the current directory?",
+          },
+        },
+      ],
+      systemPrompt: "You are a helpful file system assistant.",
+      includeContext: "thisServer",
+      maxTokens: 100,
+    },
+  },
+};
+
+describe("Form to handle sampling response", () => {
+  const mockOnApprove = jest.fn();
+  const mockOnReject = jest.fn();
+
+  afterEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it("should call onApprove with correct text content when Approve button is clicked", () => {
+    render(
+      <SamplingRequest
+        request={mockRequest}
+        onApprove={mockOnApprove}
+        onReject={mockOnReject}
+      />,
+    );
+
+    // Click the Approve button
+    fireEvent.click(screen.getByRole("button", { name: /approve/i }));
+
+    // Assert that onApprove is called with the correct arguments
+    expect(mockOnApprove).toHaveBeenCalledWith(mockRequest.id, {
+      model: "stub-model",
+      stopReason: "endTurn",
+      role: "assistant",
+      content: {
+        type: "text",
+        text: "",
+      },
+    });
+  });
+
+  it("should call onReject with correct request id when Reject button is clicked", () => {
+    render(
+      <SamplingRequest
+        request={mockRequest}
+        onApprove={mockOnApprove}
+        onReject={mockOnReject}
+      />,
+    );
+
+    // Click the Approve button
+    fireEvent.click(screen.getByRole("button", { name: /Reject/i }));
+
+    // Assert that onApprove is called with the correct arguments
+    expect(mockOnReject).toHaveBeenCalledWith(mockRequest.id);
+  });
+});

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

@@ -0,0 +1,55 @@
+import { render, screen } from "@testing-library/react";
+import { Tabs } from "@/components/ui/tabs";
+import SamplingTab, { PendingRequest } from "../SamplingTab";
+
+describe("Sampling tab", () => {
+  const mockOnApprove = jest.fn();
+  const mockOnReject = jest.fn();
+
+  const renderSamplingTab = (pendingRequests: PendingRequest[]) =>
+    render(
+      <Tabs defaultValue="sampling">
+        <SamplingTab
+          pendingRequests={pendingRequests}
+          onApprove={mockOnApprove}
+          onReject={mockOnReject}
+        />
+      </Tabs>,
+    );
+
+  it("should render 'No pending requests' when there are no pending requests", () => {
+    renderSamplingTab([]);
+    expect(
+      screen.getByText(
+        "When the server requests LLM sampling, requests will appear here for approval.",
+      ),
+    ).toBeTruthy();
+    expect(screen.findByText("No pending requests")).toBeTruthy();
+  });
+
+  it("should render the correct number of requests", () => {
+    renderSamplingTab(
+      Array.from({ length: 5 }, (_, i) => ({
+        id: i,
+        request: {
+          method: "sampling/createMessage",
+          params: {
+            messages: [
+              {
+                role: "user",
+                content: {
+                  type: "text",
+                  text: "What files are in the current directory?",
+                },
+              },
+            ],
+            systemPrompt: "You are a helpful file system assistant.",
+            includeContext: "thisServer",
+            maxTokens: 100,
+          },
+        },
+      })),
+    );
+    expect(screen.getAllByTestId("sampling-request").length).toBe(5);
+  });
+});

client/src/components/ui/toaster.tsx

@@ -1,4 +1,4 @@
-import { useToast } from "@/hooks/use-toast";
+import { useToast } from "@/lib/hooks/useToast";
 import {
   Toast,
   ToastClose,

client/src/lib/hooks/__tests__/useConnection.test.tsx

@@ -37,7 +37,7 @@ jest.mock("@modelcontextprotocol/sdk/client/auth.js", () => ({
 }));
 
 // Mock the toast hook
-jest.mock("@/hooks/use-toast", () => ({
+jest.mock("@/lib/hooks/useToast", () => ({
   useToast: () => ({
     toast: jest.fn(),
   }),

client/src/lib/hooks/useConnection.ts

@@ -3,6 +3,7 @@ import {
   SSEClientTransport,
   SseError,
 } from "@modelcontextprotocol/sdk/client/sse.js";
+import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
 import {
   ClientNotification,
   ClientRequest,
@@ -26,7 +27,7 @@ import {
 } from "@modelcontextprotocol/sdk/types.js";
 import { RequestOptions } from "@modelcontextprotocol/sdk/shared/protocol.js";
 import { useState } from "react";
-import { useToast } from "@/hooks/use-toast";
+import { useToast } from "@/lib/hooks/useToast";
 import { z } from "zod";
 import { ConnectionStatus } from "../constants";
 import { Notification, StdErrNotificationSchema } from "../notificationTypes";
@@ -42,7 +43,7 @@ import { getMCPServerRequestTimeout } from "@/utils/configUtils";
 import { InspectorConfig } from "../configurationTypes";
 
 interface UseConnectionOptions {
-  transportType: "stdio" | "sse";
+  transportType: "stdio" | "sse" | "streamable-http";
   command: string;
   args: string;
   sseUrl: string;
@@ -278,15 +279,29 @@ export function useConnection({
       setConnectionStatus("error-connecting-to-proxy");
       return;
     }
-    const mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/sse`);
+    let mcpProxyServerUrl;
-    mcpProxyServerUrl.searchParams.append("transportType", transportType);
+    switch (transportType) {
-    if (transportType === "stdio") {
+      case "stdio":
-      mcpProxyServerUrl.searchParams.append("command", command);
+        mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/stdio`);
-      mcpProxyServerUrl.searchParams.append("args", args);
+        mcpProxyServerUrl.searchParams.append("command", command);
-      mcpProxyServerUrl.searchParams.append("env", JSON.stringify(env));
+        mcpProxyServerUrl.searchParams.append("args", args);
-    } else {
+        mcpProxyServerUrl.searchParams.append("env", JSON.stringify(env));
-      mcpProxyServerUrl.searchParams.append("url", sseUrl);
+        break;
+
+      case "sse":
+        mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/sse`);
+        mcpProxyServerUrl.searchParams.append("url", sseUrl);
+        break;
+
+      case "streamable-http":
+        mcpProxyServerUrl = new URL(`${getMCPProxyAddress(config)}/mcp`);
+        mcpProxyServerUrl.searchParams.append("url", sseUrl);
+        break;
     }
+    (mcpProxyServerUrl as URL).searchParams.append(
+      "transportType",
+      transportType,
+    );
 
     try {
       // Inject auth manually instead of using SSEClientTransport, because we're
@@ -304,14 +319,24 @@ export function useConnection({
         headers[authHeaderName] = `Bearer ${token}`;
       }
 
-      const clientTransport = new SSEClientTransport(mcpProxyServerUrl, {
+      // Create appropriate transport
+      const transportOptions = {
         eventSourceInit: {
-          fetch: (url, init) => fetch(url, { ...init, headers }),
+          fetch: (
+            url: string | URL | globalThis.Request,
+            init: RequestInit | undefined,
+          ) => fetch(url, { ...init, headers }),
         },
         requestInit: {
           headers,
         },
-      });
+      };
+      const clientTransport =
+        transportType === "streamable-http"
+          ? new StreamableHTTPClientTransport(mcpProxyServerUrl as URL, {
+              sessionId: undefined,
+            })
+          : new SSEClientTransport(mcpProxyServerUrl as URL, transportOptions);
 
       if (onNotification) {
         [

client/src/lib/hooks/useTheme.ts

@@ -0,0 +1,52 @@
+import { useCallback, useEffect, useMemo, useState } from "react";
+
+type Theme = "light" | "dark" | "system";
+
+const useTheme = (): [Theme, (mode: Theme) => void] => {
+  const [theme, setTheme] = useState<Theme>(() => {
+    const savedTheme = localStorage.getItem("theme") as Theme;
+    return savedTheme || "system";
+  });
+
+  useEffect(() => {
+    const darkModeMediaQuery = window.matchMedia(
+      "(prefers-color-scheme: dark)",
+    );
+    const handleDarkModeChange = (e: MediaQueryListEvent) => {
+      if (theme === "system") {
+        updateDocumentTheme(e.matches ? "dark" : "light");
+      }
+    };
+
+    const updateDocumentTheme = (newTheme: "light" | "dark") => {
+      document.documentElement.classList.toggle("dark", newTheme === "dark");
+    };
+
+    // Set initial theme based on current mode
+    if (theme === "system") {
+      updateDocumentTheme(darkModeMediaQuery.matches ? "dark" : "light");
+    } else {
+      updateDocumentTheme(theme);
+    }
+
+    darkModeMediaQuery.addEventListener("change", handleDarkModeChange);
+
+    return () => {
+      darkModeMediaQuery.removeEventListener("change", handleDarkModeChange);
+    };
+  }, [theme]);
+
+  const setThemeWithSideEffect = useCallback((newTheme: Theme) => {
+    setTheme(newTheme);
+    localStorage.setItem("theme", newTheme);
+    if (newTheme !== "system") {
+      document.documentElement.classList.toggle("dark", newTheme === "dark");
+    }
+  }, []);
+  return useMemo(
+    () => [theme, setThemeWithSideEffect],
+    [theme, setThemeWithSideEffect],
+  );
+};
+
+export default useTheme;

client/src/lib/hooks/useToast.ts

@@ -0,0 +1,191 @@
+"use client";
+
+// Inspired by react-hot-toast library
+import * as React from "react";
+
+import type { ToastActionElement, ToastProps } from "@/components/ui/toast";
+
+const TOAST_LIMIT = 1;
+const TOAST_REMOVE_DELAY = 1000000;
+
+type ToasterToast = ToastProps & {
+  id: string;
+  title?: React.ReactNode;
+  description?: React.ReactNode;
+  action?: ToastActionElement;
+};
+
+let count = 0;
+
+function genId() {
+  count = (count + 1) % Number.MAX_SAFE_INTEGER;
+  return count.toString();
+}
+
+const enum ActionType {
+  ADD_TOAST = "ADD_TOAST",
+  UPDATE_TOAST = "UPDATE_TOAST",
+  DISMISS_TOAST = "DISMISS_TOAST",
+  REMOVE_TOAST = "REMOVE_TOAST",
+}
+
+type Action =
+  | {
+      type: ActionType.ADD_TOAST;
+      toast: ToasterToast;
+    }
+  | {
+      type: ActionType.UPDATE_TOAST;
+      toast: Partial<ToasterToast>;
+    }
+  | {
+      type: ActionType.DISMISS_TOAST;
+      toastId?: ToasterToast["id"];
+    }
+  | {
+      type: ActionType.REMOVE_TOAST;
+      toastId?: ToasterToast["id"];
+    };
+
+interface State {
+  toasts: ToasterToast[];
+}
+
+const toastTimeouts = new Map<string, ReturnType<typeof setTimeout>>();
+
+const addToRemoveQueue = (toastId: string) => {
+  if (toastTimeouts.has(toastId)) {
+    return;
+  }
+
+  const timeout = setTimeout(() => {
+    toastTimeouts.delete(toastId);
+    dispatch({
+      type: ActionType.REMOVE_TOAST,
+      toastId: toastId,
+    });
+  }, TOAST_REMOVE_DELAY);
+
+  toastTimeouts.set(toastId, timeout);
+};
+
+export const reducer = (state: State, action: Action): State => {
+  switch (action.type) {
+    case ActionType.ADD_TOAST:
+      return {
+        ...state,
+        toasts: [action.toast, ...state.toasts].slice(0, TOAST_LIMIT),
+      };
+
+    case ActionType.UPDATE_TOAST:
+      return {
+        ...state,
+        toasts: state.toasts.map((t) =>
+          t.id === action.toast.id ? { ...t, ...action.toast } : t,
+        ),
+      };
+
+    case ActionType.DISMISS_TOAST: {
+      const { toastId } = action;
+
+      // ! Side effects ! - This could be extracted into a dismissToast() action,
+      // but I'll keep it here for simplicity
+      if (toastId) {
+        addToRemoveQueue(toastId);
+      } else {
+        state.toasts.forEach((toast) => {
+          addToRemoveQueue(toast.id);
+        });
+      }
+
+      return {
+        ...state,
+        toasts: state.toasts.map((t) =>
+          t.id === toastId || toastId === undefined
+            ? {
+                ...t,
+                open: false,
+              }
+            : t,
+        ),
+      };
+    }
+    case ActionType.REMOVE_TOAST:
+      if (action.toastId === undefined) {
+        return {
+          ...state,
+          toasts: [],
+        };
+      }
+      return {
+        ...state,
+        toasts: state.toasts.filter((t) => t.id !== action.toastId),
+      };
+  }
+};
+
+const listeners: Array<(state: State) => void> = [];
+
+let memoryState: State = { toasts: [] };
+
+function dispatch(action: Action) {
+  memoryState = reducer(memoryState, action);
+  listeners.forEach((listener) => {
+    listener(memoryState);
+  });
+}
+
+type Toast = Omit<ToasterToast, "id">;
+
+function toast({ ...props }: Toast) {
+  const id = genId();
+
+  const update = (props: ToasterToast) =>
+    dispatch({
+      type: ActionType.UPDATE_TOAST,
+      toast: { ...props, id },
+    });
+  const dismiss = () =>
+    dispatch({ type: ActionType.DISMISS_TOAST, toastId: id });
+
+  dispatch({
+    type: ActionType.ADD_TOAST,
+    toast: {
+      ...props,
+      id,
+      open: true,
+      onOpenChange: (open) => {
+        if (!open) dismiss();
+      },
+    },
+  });
+
+  return {
+    id: id,
+    dismiss,
+    update,
+  };
+}
+
+function useToast() {
+  const [state, setState] = React.useState<State>(memoryState);
+
+  React.useEffect(() => {
+    listeners.push(setState);
+    return () => {
+      const index = listeners.indexOf(setState);
+      if (index > -1) {
+        listeners.splice(index, 1);
+      }
+    };
+  }, [state]);
+
+  return {
+    ...state,
+    toast,
+    dismiss: (toastId?: string) =>
+      dispatch({ type: ActionType.DISMISS_TOAST, toastId }),
+  };
+}
+
+export { useToast, toast };