---
meta:
  title: "Get started with a CodeMirror code editor using Liveblocks and React"
  parentTitle: "Quickstart"
  description:
    "Learn how to install a CodeMirror code editor using Liveblocks and React"
---

Liveblocks is a realtime collaboration infrastructure for building performant
collaborative experiences. Follow the following steps to start adding
collaboration to your React application using the APIs from the
[`@liveblocks/codemirror`](/docs/api-reference/liveblocks-codemirror) package.

## Quickstart

<PromptCta />

<Steps>
  <Step>
    <StepTitle>Install Liveblocks and CodeMirror</StepTitle>
    <StepContent>

      Every Liveblocks package should use the same version.

      ```bash trackEvent="install_liveblocks"
      npm install @liveblocks/client @liveblocks/react @liveblocks/codemirror codemirror
      ```

    </StepContent>

  </Step>
  <Step>
    <StepTitle>Initialize the `liveblocks.config.ts` file</StepTitle>
    <StepContent>

      We can use this file later to [define types for our application](/docs/api-reference/liveblocks-react#Typing-your-data).

      ```bash
      npx create-liveblocks-app@latest --init --framework react
      ```

      Add types for your CodeMirror document and presence:

      ```ts file="liveblocks.config.ts"
      import type { LiveblocksCodemirrorSelection } from "@liveblocks/codemirror";
      import { LiveText } from "@liveblocks/client";

      declare global {
        interface Liveblocks {
          Presence: {
            selection: LiveblocksCodemirrorSelection | null;
          };
          Storage: {
            document: LiveText;
          };
          UserMeta: {
            id?: string;
            info?: {
              name?: string;
              color?: string;
            };
          };
        }
      }

      export {};
      ```

    </StepContent>

  </Step>

  <Step>
    <StepTitle>Set up the Liveblocks client</StepTitle>
    <StepContent>

      Liveblocks uses the concept of rooms, separate virtual spaces where people
      collaborate, and to create a realtime experience, multiple users must
      be connected to the same room. Set up a Liveblocks client with [`LiveblocksProvider`](/docs/api-reference/liveblocks-react#LiveblocksProvider), and join a room with [`RoomProvider`](/docs/api-reference/liveblocks-react#RoomProvider).

      Store your editor document in Storage as [`LiveText`](/docs/api-reference/liveblocks-client#LiveText), and set an initial presence shape for cursors.

      ```tsx file="App.tsx"
      "use client";

      import { LiveText } from "@liveblocks/client";
      import {
        LiveblocksProvider,
        RoomProvider,
      } from "@liveblocks/react/suspense";
      import { Editor } from "./Editor";

      export default function App() {
        return (
          <LiveblocksProvider publicApiKey={"{{PUBLIC_KEY}}"}>
            <RoomProvider
              id="my-room"
              // +++
              initialPresence={{ selection: null }}
              initialStorage={{ document: new LiveText("Hello, world") }}
              // +++
            >
              {/* ... */}
            </RoomProvider>
          </LiveblocksProvider>
        );
      }
      ```

    </StepContent>

  </Step>
  <Step>
    <StepTitle>Join a Liveblocks room</StepTitle>
    <StepContent>

      After setting up the room, you can add collaborative components inside it, using
      [`ClientSideSuspense`](/docs/api-reference/liveblocks-react#ClientSideSuspense) to add loading spinners to your app.

      ```tsx file="App.tsx"
      "use client";

      import { LiveText } from "@liveblocks/client";
      import {
        LiveblocksProvider,
        RoomProvider,
        ClientSideSuspense,
      } from "@liveblocks/react/suspense";
      import { Editor } from "./Editor";

      export default function App() {
        return (
          <LiveblocksProvider publicApiKey={"{{PUBLIC_KEY}}"}>
            <RoomProvider
              id="my-room"
              initialPresence={{ selection: null }}
              initialStorage={{ document: new LiveText("Hello, world") }}
            >
              <ClientSideSuspense fallback={<div>Loading…</div>}>
                <Editor />
              </ClientSideSuspense>
            </RoomProvider>
          </LiveblocksProvider>
        );
      }
      ```

    </StepContent>

  </Step>
  <Step>
    <StepTitle>Set up the collaborative CodeMirror editor</StepTitle>
    <StepContent>

      Now that Liveblocks is set up, create a CodeMirror editor in `Editor.tsx`.
      Use [`createLiveblocksSyncPlugin`](/docs/api-reference/liveblocks-codemirror#createLiveblocksSyncPlugin)
      to sync the document with Storage, and
      [`createLiveblocksPresencePlugin`](/docs/api-reference/liveblocks-codemirror#createLiveblocksPresencePlugin)
      to show remote carets and selections.

      ```tsx file="Editor.tsx"
      "use client";

      import { useCallback, useEffect, useRef, useSyncExternalStore } from "react";
      import { EditorView } from "@codemirror/view";
      import { EditorState } from "@codemirror/state";
      import type { LiveText, Room } from "@liveblocks/client";
      import {
        createLiveblocksPresencePlugin,
        createLiveblocksSyncPlugin,
      } from "@liveblocks/codemirror";
      import { useRoom } from "@liveblocks/react/suspense";

      export function Editor() {
        const room = useRoom();
        const root = useRoot(room);

        if (root == null) {
          return <div>Loading…</div>;
        }

        return <EditorInner text={root.get("document")} />;
      }

      function EditorInner({ text }: { text: LiveText }) {
        const room = useRoom();
        const containerRef = useRef<HTMLDivElement>(null);

        useEffect(() => {
          if (containerRef.current === null) return;

          const view = new EditorView({
            parent: containerRef.current,
            state: EditorState.create({
              // +++
              doc: text.toString(),
              extensions: [
                createLiveblocksSyncPlugin(room, text),
                createLiveblocksPresencePlugin(room, text),
              ],
              // +++
            }),
          });

          return () => {
            view.destroy();
          };
        }, [room, text]);

        return <div ref={containerRef} className="editor" />;
      }

      function useRoot(room: Room) {
        const subscribe = room.events.storageDidLoad.subscribeOnce;
        const getSnapshot = room.getStorageOrNull;
        const getServerSnapshot = useCallback(() => null, []);
        return useSyncExternalStore(subscribe, getSnapshot, getServerSnapshot);
      }
      ```

    </StepContent>

  </Step>
  <Step>
    <StepTitle>Style remote carets and selections</StepTitle>
    <StepContent>

      The presence plugin renders remote carets and selections using the
      `.lb-remote-caret` and `.lb-remote-selection` class names. Add styles for
      them in your CSS. This package does not ship a stylesheet.

      ```css file="globals.css"
      .editor {
        height: 100%;
      }

      .lb-remote-selection {
        position: absolute;
        background-color: color-mix(in srgb, var(--lb-remote-color) 25%, transparent);
        border-radius: 1px;
        pointer-events: none;
        box-sizing: border-box;
      }

      .lb-remote-caret {
        position: absolute;
        width: 0;
        border-left: 2px solid var(--lb-remote-color);
        pointer-events: none;
        box-sizing: border-box;
      }
      ```

      ```tsx file="main.tsx"
      import "./globals.css";
      ```

    </StepContent>

  </Step>
  <Step lastStep>
    <StepTitle>Next: authenticate and add your users</StepTitle>
    <StepContent>
      Your editor is set up and working now, but each user is anonymous—the next step is to
      authenticate each user as they connect, and attach their name and color to remote carets.

      <Button asChild className="not-markdown">
        <a href="/docs/guides/how-to-add-users-to-liveblocks-presence-components">
          Set up authentication and add user information
        </a>
      </Button>
    </StepContent>

  </Step>

</Steps>

## What to read next

Congratulations! You now have set up the foundation for your collaborative
CodeMirror editor inside your React application.

- [@liveblocks/codemirror API Reference](/docs/api-reference/liveblocks-codemirror)
- [CodeMirror website](https://codemirror.net)

If you prefer to use Yjs with CodeMirror, see the
[Yjs CodeMirror React quickstart](/docs/get-started/yjs-codemirror-react).

---

For an overview of all available documentation, see [/llms.txt](/llms.txt).