I Ran Out of Codex Quota, So I Built an Open-Source Tool That Lets ChatGPT Web Work With My Local Project

If you use ChatGPT on the web for coding, you know the pain: copy code from a browser tab, paste it into your editor, run it, copy the error back, repeat. ChatGPT can't see your file tree, can't use your terminal, and has no idea whether its changes actually work on your machine.

And if you've ever hit your Codex quota halfway through a task, it's worse: you're stuck until the limit resets.

So I built Nexus, and today I'm releasing v1.20.0.

⭐ If you find it interesting, a star on GitHub is the easiest way to support it: ysunyang979-sys/Nexus-Web-ChatGPT

What is Nexus?

Nexus is an open-source Local AI Control Plane for ChatGPT Web. It's a desktop app built with Tauri 2 + Rust + React that runs on your machine and connects chatgpt.com to your local workstation through a secure MCP tunnel, with strict, auditable security boundaries.

It's released under AGPL-3.0, with installers for Windows, macOS (Apple Silicon) and Linux.

What can ChatGPT do through Nexus?

Nexus ships with 332 tools across 24 capability domains:

• Filesystem access and AST-aware code edits

• Git support, including managed worktrees so ChatGPT can experiment in isolated branches

• Persistent node-pty terminals and background jobs

• Built-in LSP code intelligence (TypeScript / Python)

• Headless and interactive browser automation

• Native Windows Computer Use (WinRT OCR + Accessibility UI Tree)

• A local SQLite-backed store for memory, rules, knowledge and prompts

Security was the first design goal

Giving an AI access to your computer only makes sense if you stay in control:

• Per-project sandboxing: authorize specific folders and switch live, without restarting, between read-only / read-write access and disabled / safe-only / project-code execution.

• Path protection: paths are canonicalized (fs.realpathSync.native) to block ../ traversal and NTFS junction / symlink escapes.

• Command risk classification: AST-based rating as SAFE, CAUTION or DANGEROUS. Destructive commands such as rm -rf /, format and reg delete are blocked by default.

• Secret masking: .env*, *.pem, *.key, id_rsa and cloud credentials are masked automatically.

• ACID action ledger (WAL): every side-effecting tool call is written to a write-ahead log before it runs, giving you a live audit trail, crash recovery and idempotent replay after network drops.

Set it up in a few minutes

Full step-by-step tutorial: https://nexus.ycu.de5.net/

1. Install Nexus. Download the installer from GitHub Releases, or build from source:

pnpm install && pnpm run build

Wait for the status bar to show Engine Connected.

2. Create a tunnel and an API key on the OpenAI Platform. Both are free to create:

• Tunnel: https://platform.openai.com/settings/organization/tunnels (copy the Tunnel ID)

• API key: https://platform.openai.com/settings/organization/api-keys (this is your Runtime API Key)

⚠️ An API key is a secret. Never share it or commit it to a repo. Create a dedicated key just for Nexus so you can revoke it independently.

3. Generate a local MCP token. In Nexus, go to Settings → MCP & Tokens, pick a scope preset and click Auto-Generate Token. The local endpoint is http://127.0.0.1:18080/mcp. On Windows the token is stored encrypted with DPAPI, which is a Windows-specific feature.

4. Configure the tunnel. Open Tunnel Settings, enter the Tunnel ID, Runtime API Key and your local MCP token, then click Save & Connect and Test Readiness until it shows ChatGPT Ready.

5. Create the MCP app on ChatGPT Web. On chatgpt.com, open Plugins, click +, choose Create MCP app, set the connection to Tunnel, select your tunnel, set authentication to No authentication, tick the confirmation box and click Create.

6. Start working. Open a new chat, enable the plugin, and ask ChatGPT to read files, edit code, run commands or manage Git worktrees in your authorized project.

Tip: start with read-only access and safe-only execution, then loosen permissions per project once you're comfortable.

What's next

Right now Nexus is dedicated to ChatGPT Web. Support for more AI clients and platforms is planned for future releases.

If you like it, please give it a star ⭐

Nexus is free and open source, and a GitHub star is the simplest way to support it. It helps other developers find the project and keeps me motivated to keep improving it.

• ⭐ Star on GitHub: https://github.com/ysunyang979-sys/Nexus-Web-ChatGPT

• 🌐 Website & tutorial: https://nexus.ycu.de5.net/

Bug reports, feature requests and pull requests are all welcome. Thanks for reading!