Flexnote MCP: Access Your Local Knowledge Base from Cursor and Codex

When working in Cursor or Codex, it is often necessary to consult local notes: prior decisions, literature excerpts, or a board layout. Copying text into another chat, or switching applications, splits the knowledge base from the current workflow.

The Flexnote desktop application now includes an MCP server (Model Context Protocol). The service listens on 127.0.0.1 only. Clients that implement the protocol—including Cursor, Claude Desktop, and Codex—can search, read, and write the current library. Data remains on the user's device and is not uploaded to a third-party notes cloud.

1. How MCP differs from in-app Flexnote AI

MCP is an open protocol for declaring tools that an external AI client may call. The client lists tools, invokes them by name, and receives JSON text. The model is chosen by the client; Flexnote does not mediate billing or the provider.

In-app Flexnote AI runs in the sidebar: it uses the API key configured in Settings, answers may include citations, and Agent can edit the board. MCP exposes the same library to external development tools, so daily notes, cards, todos, and whiteboards can be used without leaving the editor.

2. Scope

Cards, daily notes, whiteboards, todos, tags, and collections in the current workspace can be queried. Write tools require read-only mode to be turned off. Canvas operations require a whiteboard ID. If the board is not open, Flexnote navigates to it and waits until the canvas is ready, so the client request does not time out.

3. Enabling the server

MCP is a Pro feature. A valid membership sign-in is required, and the Flexnote desktop application must be running. After the application quits, the local port closes and clients cannot connect.

1. Open Flexnote → Settings → MCP server.
2. Enable the service. It binds to loopback only. The default port is 39125.
3. Copy the configuration for the client: HTTP JSON for Cursor / Claude Desktop; a stdio bridge for clients that launch a command; TOML for Codex CLI.
4. Add the configuration to the client. The access token is for local authentication only. Do not commit it to a public repository or share it.

Two additional options are relevant: read-only mode exposes query tools only and is appropriate for the first connection test; individual tools can be disabled if they should not be available to an external model.

4. Connecting Cursor, Claude Desktop, and Codex

Cursor / Claude Desktop

Use the HTTP configuration from Settings. The required fields are the local URL and the Bearer token:

{
  "mcpServers": {
    "flexnote": {
      "url": "http://127.0.0.1:39125/mcp",
      "headers": { "Authorization": "Bearer YOUR_TOKEN" }
    }
  }
}

Codex CLI

Codex CLI typically uses a stdio bridge: Node runs a script provided by Flexnote and forwards standard input to the local HTTP endpoint. Settings can copy the TOML configuration and locate the script. Set FLEXNOTE_MCP_URL and FLEXNOTE_MCP_TOKEN in the environment.

5. Example requests

After the connection is established, tool names are not required. Natural-language requests are sufficient. The following statements can be used to verify the integration:

• "Which Flexnote workspace is currently open? List recent whiteboards and five cards. Do not modify any data."
• "Append this conclusion to today's daily note. Create the note if it does not exist. Do not save it as a regular note card."
• "Create a note titled MCP trial. The body must start with a Markdown heading 1."
• "On the specified whiteboard (provide whiteboardId), create two sticky notes, connect them, then read the canvas layout."
• "List todos and mark one of them complete."

After a successful write, Flexnote displays a notification in the window. If a matching entity exists, View opens the corresponding page; otherwise the interface can be refreshed. The notification remains until it is dismissed.

6. Security

The service listens on localhost only. Other processes on the same device that hold the access token can call the same tools. Treat the token as a credential. Regenerating it in Settings invalidates previous configurations immediately.

When write tools are enabled, an external model can modify the library. For initial verification, enable read-only mode or disable create, delete, and whiteboard tools. MCP applies only to the currently open workspace. Confirm the workspace before write operations.

7. Limitations

• Browser-only use without the desktop application provides no local MCP port.
• This is not a team gateway and does not offer public-network access. It is not intended for sharing a library with other people.
• Flexnote is not a real-time multiplayer whiteboard, and MCP does not add that capability. See What is Flexnote for the product scope.

8. Getting started

Update the desktop application to a build that includes MCP, sign in with a Pro account, enable the server in Settings, and add the configuration to Cursor or Codex. Verify search in read-only mode before enabling writes. Download the client from the download page. Pro details are on pricing.

Existing in-app knowledge Agent workflows do not need to change. MCP connects the same local library to external development tools.