Tutorial: Free Claude 4.7 Model Access in Cursor via MCP & Security Risk Analysis

Introduction: The "Unlimited Free" Scheme Circulating in Communities

Recently, a method has been circulating in tech communities (such as Bilibili) that claims to enable "zero-cost" access to the latest large language models like Claude 4.7 and GPT-5.5 within Cursor through MCP (Model Context Protocol) configuration. The scheme claims to bypass Cursor's usage limits, enabling unlimited free access to top-tier AI models. This article provides a technical breakdown of the workflow while objectively analyzing the security risks and controversies involved.

Disclaimer: This article is for technical analysis purposes only and does not encourage any behavior that violates terms of service. Using such methods may violate Cursor's user agreement and carries risks including account suspension.

Core Principles Behind the Cursor MCP Free Access Scheme

What Is MCP?

MCP (Model Context Protocol) is a protocol that allows AI editors to interact with external tools and services. Officially open-sourced by Anthropic in November 2024, it was designed to solve the "context silo" problem between AI models and external tools — before MCP, each AI application needed to develop separate integration solutions for different data sources and tools, resulting in massive duplication of effort. MCP uses a standardized client-server architecture based on JSON-RPC 2.0, supporting three core capabilities: Tool Use, Resource Access, and Prompt Templates, enabling AI models to access file systems, databases, API services, and other external resources in a unified manner. Currently, mainstream AI tools including VS Code, Cursor, and Claude Desktop have integrated into the MCP ecosystem, with the number of third-party MCP servers already exceeding several thousand.

In normal use cases, MCP is used to connect databases, API endpoints, file systems, and other external resources, allowing AI assistants to perform more complex tasks.

The core idea behind this scheme is: routing Cursor's conversation requests to a third-party proxy service via MCP, thereby bypassing Cursor's official model usage billing system. In simple terms, Cursor merely serves as a frontend interface while the actual model inference requests are routed to other servers.

Detailed Workflow: How to Configure MCP for Free Access

Step 1: Prepare the Toolkit

According to the video demonstration, the scheme provides a pre-packaged toolkit containing:

• Video tutorial and text guide: Detailed configuration steps
• ID plugin: A plugin related to identity identification
• Old Cursor installer: A specific version of the Cursor client
• JS injection script: The critical JavaScript code file
• Prompt templates: Pre-configured system prompts

Step 2: Inject JS Script into Cursor

This is the most critical and highest-risk step in the entire process. It's important to understand that Cursor is built on the Electron framework, which is essentially a Chromium browser environment running on the desktop with built-in Chrome DevTools (Developer Tools) that allow execution of arbitrary JavaScript code. Executing JS scripts via the F1 command palette to invoke developer tools is essentially equivalent to running code in a browser console, with full permissions to access application memory, network requests, and local storage. In security research, this type of attack vector is known as "Local Privilege Escalation" — attackers can use it to read authentication tokens (Auth Tokens), session cookies, and even hijack ongoing network requests.

The operator needs to:

1. Open a new conversation window in Cursor
2. Press F1 to open the command palette
3. Find the "Developer" related option
4. Load the pre-prepared JS file, select all, copy, and paste to execute

After execution, a special "FY" indicator appears on the new conversation window interface, confirming successful script injection.

Step 3: Configure MCP Service Connection

After successful script injection, MCP configuration is still needed:

1. Copy the pre-configured prompt
2. Click the "FY" indicator button
3. Enter the configuration interface and click the "Configure" button to complete the MCP service connection
4. The system will automatically upload the new conversation to the MCP server

In the video, the demonstrator noted that after configuration, the number of conversations on the MCP server increased from 6 to 7, confirming a successful connection.

Step 4: Verify Free Access

After configuration, the operator tested with the Claude 4.7 highest thinking model. Based on the demonstration:

• The model responded to conversation requests normally
• The usage consumption displayed in the bottom right corner remained at zero
• Consumption remained unchanged even after multiple inputs

In-Depth Analysis of Technical Risks and Security Controversies

Security Risks of Executing Unknown JS Scripts

Although this method appears "free and functional"