How to Use Skylos as a Cursor Security Scanner for Python

Cursor is effective because it compresses the distance between idea and implementation.

It can also compress the distance between "this looks fine" and "we just merged a silent regression."

Cursor now supports MCP connections, multiple transports, approval flows, and even auto-run behavior. That is powerful. It also means your Python review workflow should assume the assistant can produce bigger, faster, and more operationally connected changes than autocomplete ever could.

Skylos fits as the verification layer around that workflow.

What a Cursor security scanner should catch

A useful Cursor security workflow does not stop at "find one dangerous function."

It should catch at least four classes of issues:

  1. Insecure code patterns SQL injection, command execution, unsafe deserialization, disabled TLS verification, and similar risks.

  2. Dead code AI tools often leave behind unused helpers, wrappers, and fallback branches after refactors.

  3. Secrets Hardcoded keys, tokens, passwords, and internal endpoints often show up in generated examples and temporary fixes.

  4. Regressions in existing protections The AI did not add a vulnerability from scratch. It removed or weakened the guardrail that used to be there.

That fourth category is where many Cursor-heavy teams still have the weakest process.

The practical workflow

1. Run the local scan before you commit

skylos . -a

This gives you a fast read on:

  • security findings
  • dead code
  • hardcoded secrets
  • framework-aware issues in Django, Flask, FastAPI, Pydantic, pytest, and similar Python patterns

For Cursor users, this is the simplest way to keep speed without trusting the draft blindly.

2. Add a pre-commit hook

If you already use pre-commit, add Skylos to the local flow:

repos:
  - repo: local
    hooks:
      - id: skylos
        name: skylos
        entry: skylos . -a
        language: system
        pass_filenames: false

This is not about perfect enforcement. It is about making verification the default path instead of the exceptional one.

3. Scan the PR diff

When Cursor rewrites a handler, service, or policy module, the highest-risk change may be something it removed.

Run:

skylos diff main..HEAD --danger

This is how you catch:

  • removed auth decorators
  • dropped validation
  • weakened CORS or CSRF checks
  • missing rate limiting
  • deleted audit or permission checks

4. Gate the repository once

After the local workflow feels stable:

skylos cicd init

That gives you a shared merge barrier instead of relying on whoever happened to run a local scan that day.

Where Cursor-specific risk actually increases

Cursor's docs make it clear that MCP tools can run locally or remotely, and the client can operate with tool approvals or more automated behavior.

That means the risk surface grows when you combine:

  • remote MCP servers
  • broad tool access
  • auto-run habits
  • long tool outputs
  • large refactors generated from natural-language instructions

If you use Cursor with MCP, pair it with two habits:

  1. keep approvals on for sensitive tools
  2. verify the resulting code with static analysis and diff analysis

Cursor plus LLM-app code needs one more check

If the project itself is an LLM application, run:

skylos defend .

This is the right follow-up when Cursor touches:

  • prompt construction
  • RAG retrieval layers
  • model routing
  • output handling
  • tool-calling logic
  • tenant or policy controls around AI features

Cursor can help you ship these systems faster. It cannot certify that the architecture remains safe after a refactor.

A lightweight review rubric for Cursor-generated Python code

Use these review questions:

  • Did this change remove an existing security control?
  • Did the assistant add a secret, internal hostname, or debug convenience?
  • Does every new helper still have real callers?
  • Did route, middleware, or validation behavior change in a way the tests might not cover?
  • If MCP tools were involved, did the task require that level of access?

If the answer to any of those is unclear, the scan should block the merge until you resolve it.

For a Python team using Cursor seriously, this is the setup that covers most failure modes:

  1. skylos . -a before commit
  2. pre-commit hook for routine scanning
  3. skylos diff main..HEAD --danger in PRs
  4. skylos defend . for LLM-powered products
  5. approval still enabled for high-impact MCP tools

That is enough to make Cursor a lot safer without turning the workflow into enterprise theater.

Where to go next

References