The One-to-One Chat feature provides a streamlined direct messaging interface, making it ideal for support chats, dating apps, and private messaging platforms. This setup eliminates distractions by focusing solely on a dedicated chat window.
Tip: You can fork the sandbox, insert your CometChat credentials (App ID, Region, Auth Key.) in the code, and immediately preview how the UI and messages respond in real time.

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User Interface Preview

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Key Components

  1. Chat Header – Displays recipient details and optional call/video call buttons.
  2. Message View – Shows real-time chat history.
  3. Message Input Box – Enables users to send messages, media, and reactions.

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Step-by-Step Guide

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Step 1: Implement the Chat Header

  • Display profile picture, name, and online status.
  • Add voice and video call buttons (optional).
<CometChatMessageHeader user={selectedUser} group={selectedGroup} />

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Step 2: Build the Message View

  • Load chat history and real-time messages.
  • Ensure smooth scrolling and timestamp visibility.
<CometChatMessageList user={selectedUser} group={selectedGroup} />

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Step 3: Add the Message Composer

  • Include a text input field.
  • Support media uploads, file attachments, emojis, and reactions.
<CometChatMessageComposer user={selectedUser} group={selectedGroup} />

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Implementation

Now we will create the CometChatNoSSR.tsx & CometChatNoSSR.css files. Here, we will initialize the CometChat UI Kit, log in a user, and build the messaging experience using CometChatMessageHeader, CometChatMessageList, and CometChatMessageComposer components. 
src/
│── CometChatNoSSR/
│   ├── CometChatNoSSR.tsx
│   ├── CometChatNoSSR.css
CometChatNoSSR.tsx
import React, { useEffect, useState } from "react";
import { CometChatMessageComposer, CometChatMessageHeader, CometChatMessageList, CometChatUIKit, UIKitSettingsBuilder } from "@cometchat/chat-uikit-react";
import { CometChat } from "@cometchat/chat-sdk-javascript";
import "./CometChatNoSSR.css";

const COMETCHAT_CONSTANTS = {
  APP_ID: "",
  REGION: "",
  AUTH_KEY: "",
};

const CometChatNoSSR: React.FC = () => {
  const [user, setUser] = useState<CometChat.User | undefined>(undefined);
  const [selectedUser, setSelectedUser] = useState<CometChat.User | undefined>(undefined);
  // eslint-disable-next-line @typescript-eslint/no-unused-vars
  const [selectedGroup, setSelectedGroup] = useState<CometChat.Group | undefined>(undefined);

  useEffect(() => {
    const UIKitSettings = new UIKitSettingsBuilder()
      .setAppId(COMETCHAT_CONSTANTS.APP_ID)
      .setRegion(COMETCHAT_CONSTANTS.REGION)
      .setAuthKey(COMETCHAT_CONSTANTS.AUTH_KEY)
      .subscribePresenceForAllUsers()
      .build();

    CometChatUIKit.init(UIKitSettings)
      ?.then(() => {
        console.log("Initialization completed successfully");
        CometChatUIKit.getLoggedinUser().then((loggedInUser) => {
          if (!loggedInUser) {
            CometChatUIKit.login("superhero1")
              .then((user) => {
                console.log("Login Successful", { user });
                setUser(user);
              })
              .catch((error) => console.error("Login failed", error));
          } else {
            console.log("Already logged-in", { loggedInUser });
            setUser(loggedInUser);
          }
        });
      })
      .catch((error) => console.error("Initialization failed", error));
  }, []);

  useEffect(() => {
    if (user) {
      // Fetch user or group from CometChat SDK whose chat you want to load. 

      /** Fetching User */
      const UID = "cometchat-uid-1";
      CometChat.getUser(UID).then(
        user => {
          setSelectedUser(user);
        }, error => {
          console.log("User fetching failed with error:", error);
        }
      );

      /** Fetching Group */
      // const GUID = "GUID"
      // CometChat.getGroup(GUID).then(
      //   group => {
      //     setSelectedGroup(group);
      //   }, error => {
      //     console.log("User fetching failed with error:", error);
      //   }
      // );
    }
  }, [user]);

  return user ? (
    <>
      {selectedUser || selectedGroup ? (
        <div className="messages-wrapper">
          <CometChatMessageHeader user={selectedUser} group={selectedGroup} />
          <CometChatMessageList user={selectedUser} group={selectedGroup} />
          <CometChatMessageComposer user={selectedUser} group={selectedGroup} />
        </div>
      ) : (
        <div className="empty-conversation">Select Conversation to start</div>
      )}
    </>
  ) : undefined;
};

export default CometChatNoSSR;
In the code snippet above, ensure you select either a user or a group based on your chat requirement. You can also determine this dynamically depending on the conversation type.

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Fetching a User (One-on-One Chat)

const UID = "cometchat-uid-1";
CometChat.getUser(UID).then(
    user => {
        setSelectedUser(user);
    }, error => {
        console.log("User fetching failed with error:", error);
    }
);

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Fetching a Group (Group Chat)

const GUID = "GUID"
CometChat.getGroup(GUID).then(
    group => {
        setSelectedGroup(group);
    }, error => {
        console.log("User fetching failed with error:", error);
    }
);

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Step 4: Disabling SSR for CometChatNoSSR.tsx in Next.js

In this update, we will disable Server-Side Rendering (SSR) for CometChatNoSSR.tsx while keeping the rest of the application’s SSR functionality intact. This ensures that the CometChat UI Kit components load only on the client-side, preventing SSR-related issues.

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Disabling SSR in index.tsx

Modify your index.tsx file to dynamically import the CometChatNoSSR.tsx component with { ssr: false }.
index.tsx
import { Inter } from "next/font/google";
import dynamic from "next/dynamic";

import '@cometchat/chat-uikit-react/css-variables.css';

const inter = Inter({ subsets: ["latin"] });

// Dynamically import CometChat component with SSR disabled
const CometChatComponent = dynamic(() => import("../CometChatNoSSR/CometChatNoSSR"), {
  ssr: false,
});

export default function Home() {
  return <CometChatComponent />;
}

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Why disable SSR?

  • The CometChat UI Kit depends on browser APIs (window, document, WebSockets).
  • Next.js pre-renders components on the server, which can cause errors with browser-specific features.
  • By setting { ssr: false }, we ensure that CometChatNoSSR.tsx only loads on the client.

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Step 5: Update Global CSS

Next, add the following styles to global.css to ensure CometChat UI Kit is properly styled.
global.css
:root {
  --background: #ffffff;
  --foreground: #171717;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #0a0a0a;
    --foreground: #ededed;
  }
}

/** Give your App a height of `100%`. Keep other CSS properties in the below selector as it is. */
.root {
  height: 100%;
}

#__next {
  height: 100%;
}

html,
body {
  height: 100%;
}

html,
body {
  max-width: 100vw;
  overflow-x: hidden;
}

body {
  color: var(--foreground);
  background: var(--background);
  font-family: Arial, Helvetica, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

@media (prefers-color-scheme: dark) {
  html {
    color-scheme: dark;
  }
}

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Step 6: Run the project

npm run dev

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Next Steps

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Enhance the User Experience