How to Secure Cursor IDE: Complete Data Protection Setup Guide
Cursor sends your code to AI APIs with every keystroke. Here's how to set up PII and secret scanning so sensitive data never leaves your machine.
Cursor is one of the most popular AI-powered code editors, with millions of developers using it daily. But every time Cursor sends a prompt to its AI backend, it includes your code context — and whatever secrets or PII are in it.
This guide shows you how to set up a local scanning proxy so that every AI request from Cursor is scanned for PII and secrets before it leaves your machine.
The Risk: What Cursor Sends to AI
When you use Cursor's AI features (Tab completion, Chat, Cmd+K), it sends:
- The current file — including any hardcoded credentials or test data
- Open files — for context, which may include config files with secrets
- Terminal output — if you reference recent terminal output, it may include log data with PII
- Codebase context — depending on your settings, Cursor indexes your project and may send relevant snippets
This means that a single Cursor AI request might include your .env file contents, database credentials from a config file, and customer PII from a test fixture — all without you deliberately pasting anything.
Setup: AxSentinel as a Cursor Proxy
The fix is simple. AxSentinel runs as a local HTTP proxy that sits between Cursor and the AI API. Every request passes through it, gets scanned in <5ms, and is either forwarded (clean) or blocked (contains secrets/PII).
Step 1: Install AxSentinel
Download from your dashboard at ax-sentinel.com/dashboard/setup:
- Windows — download the installer (.exe) and run it
- Linux — download the .deb package or standalone binary
The binary is ~10MB and runs entirely locally. No cloud account required for basic regex scanning.
Step 2: Start the Proxy
axsentinel --proxy --port 8990You'll see:
AxSentinel proxy listening on port 8990
Mode: block (secrets and PII will be rejected)
Scanner: regex + ML (6.9M param model loaded)Step 3: Configure Cursor
Open Cursor Settings (Ctrl+Shift+J or Cmd+Shift+J) and set:
- OpenAI API Base URL:
http://localhost:8990/v1
That's it. All of Cursor's AI requests now route through AxSentinel.
Step 4: Verify It Works
Create a test file with a fake secret:
# test_scan.py
API_KEY = "sk_live_51H7abcdef1234567890"
DATABASE = "postgres://admin:password123@prod.db.com/main"Ask Cursor to explain this file. AxSentinel should block the request and log:
[BLOCKED] 2 secrets detected: STRIPE_KEY, DATABASE_URIConfiguration Options
Block vs Redact Mode
# Block mode (default) — reject requests containing secrets
axsentinel --proxy --port 8990 --mode block
# Redact mode — strip secrets and forward the cleaned request
axsentinel --proxy --port 8990 --mode redactBlock mode is safer — the request never reaches the AI provider. Redact mode is more developer-friendly — the AI still gets the code context, just with secrets replaced by [REDACTED].
Fast Mode (Regex Only)
If you want maximum speed and don't need ML-powered detection:
axsentinel --proxy --port 8990 --fastThis uses only regex patterns (SSNs, credit cards, AWS keys, common API key formats). Detection takes ~0.1ms instead of ~5ms. Good for teams on the free tier or CI/CD pipelines.
Logging
# Log detections to a file
axsentinel --proxy --port 8990 --log /var/log/axsentinel.logDesktop App
For a GUI experience, install the AxSentinel Desktop app (Windows/Linux). It manages the proxy for you — start/stop with one click, view logs, download updates, and see detection stats.
What Gets Detected
| Category | Examples | Method |
|---|---|---|
| AWS credentials | `AKIA...`, secret access keys | Regex |
| API keys | Stripe, GitHub, Slack, OpenAI, Anthropic | Regex |
| Database URIs | postgres://, mongodb://, redis:// | Regex |
| Private keys | RSA, Ed25519, PGP blocks | Regex |
| SSNs | XXX-XX-XXXX | Regex |
| Credit cards | 16-digit patterns with Luhn check | Regex |
| Email addresses | Standard RFC 5322 | Regex |
| Custom secrets | Non-standard key formats, internal tokens | ML |
| Names in context | Real names in code comments, logs | ML |
| Encoded secrets | Base64-encoded credentials | ML |
Team Deployment
For teams, deploy AxSentinel via your configuration management:
# Each developer runs:
axsentinel setup
# Prompts for org ID and client token (from your admin dashboard)
# Start proxy with telemetry (detections reported to team dashboard)
axsentinel --proxy --port 8990Your compliance dashboard at ax-sentinel.com/dashboard shows detection events across the entire team — which developers, which types of secrets, which AI tools.