Sylix – Free AI Code Editor Built in Rust

TL;DR

TL;DR: Sylix is a free, local-first AI code editor built in Rust. Under 35MB, brings your VS Code/Cursor themes and keybinds, and runs a Verify Loop to test changes before marking them done.

Source and Accuracy Notes

⚠️ This section is MANDATORY. All links must be verified from actual source, not guessed.

• Project page: sylixide.com — verified, page loads with full feature description
• Source repository: No public GitHub repo confirmed at time of writing
• License: Free / BYOK (Bring Your Own Key) — no funding or YC affiliation detected
• HN launch thread: news.ycombinator.com/item?id=48785897 — Show HN, “Sylix, a free native Cursor/Antigravity alternative”
• Source last checked: 2026-08-11

What Is Sylix?

Sylix is a free, native AI code editor built from scratch in Rust. Unlike Cursor (which is a VS Code fork) or GitHub Copilot (a VS Code extension), Sylix is an independent codebase designed from the ground up for local-first, privacy-preserving AI pair programming.

The product’s main pitch on its landing page:

“Finally, an AI code editor that doesn’t send your code to the cloud. Use any model. Keep full control. Under 35MB.”

Key differentiating claims:

• Built in Rust — not a VS Code fork, compiled to a small native binary
• Local embeddings — code context processed locally, not sent to a third-party API
• Verify Loop — when Sylix writes code, it runs your existing tests to confirm the change works before marking it done
• One-click switch — imports your themes, keybindings, and settings from VS Code, Cursor, Antigravity, or Zed
• Under 35MB — self-contained binary, no Electron overhead

Setup Workflow

Step 1: Download

Download Sylix for Windows from the official site at sylixide.com. The binary is under 35MB.

Step 2: Bring Your Own API Key

Sylix is BYOK (Bring Your Own Key). You configure your own API credentials for the AI model you want to use. No account creation or vendor lock-in required.

Step 3: Import Your Settings

On first launch, Sylix prompts you to import settings from an existing editor:

• VS Code
• Cursor
• Antigravity
• Zed

Your themes, keybindings, and editor settings are transferred in one click.

Step 4: Configure Your Model

Sylix supports connecting to any model that exposes a compatible API endpoint. The Context Engine indexes your entire codebase using Rust-native AST parsing and local embeddings, giving Sylix full project-level understanding beyond just the open file.

Deeper Analysis

Context Engine

Sylix’s Context Engine is architecturally different from cursor-style context aggregation. It uses Rust-native AST parsing to build a semantic map of your entire codebase, then runs local embeddings to create a project-wide context index. The stated goal is for Sylix to understand your project structure, not just the currently open file.

Verify Loop

The Verify Loop is Sylix’s answer to AI code quality. When the AI writes or modifies code, Sylix automatically runs your existing test suite against the changes. If tests pass, the change is confirmed. If tests fail, Sylix iterates. This is a meaningful difference from editors that rely solely on the model’s self-assessment.

Local-First Privacy

Because Sylix uses local embeddings and a BYOK model, your codebase never leaves your machine for context purposes. You choose which model to connect to and which API key to use. The binary itself is small enough to audit.

Comparison Table

| Feature | Sylix | Cursor | Zed | |---|---|---|---| | Base | Rust (native) | VS Code fork | Rust (native) | | Privacy | Local embeddings + BYOK | Cloud API | Local + BYOK | | Size | Under 35MB | ~200MB+ | ~50MB | | Fork of VS Code | No | Yes | No | | Auto-test on edit | Verify Loop | No | No | | Settings import | VS Code, Cursor, Antigravity, Zed | VS Code | VS Code keybindings |

Practical Evaluation Checklist

• [ ] Download and install Sylix (under 35MB)
• [ ] Import settings from existing editor (VS Code, Cursor, Antigravity, Zed)
• [ ] Configure your own API key (BYOK)
• [ ] Open a multi-file project and verify Context Engine indexing
• [ ] Trigger an AI edit and confirm Verify Loop runs tests
• [ ] Verify no code is sent to third-party servers for context (network inspection)

Security Notes

• BYOK model — you supply your own API key; no vendor-managed credentials
• Local embeddings — code context is processed locally by default
• No telemetry mentioned — the product page makes no claims about anonymous telemetry or crash reporting; treat accordingly until confirmed otherwise
• Auditability — at under 35MB as a native binary, Sylix is small enough for a security researcher to audit statically

FAQ

Q: Is Sylix a fork of VS Code? A: No. Sylix is built from scratch in Rust. It imports settings from VS Code, Cursor, Antigravity, and Zed, but the codebase is independent.

Q: Does Sylix send my code to the cloud? A: The stated design is local-first: the Context Engine uses local embeddings, and the BYOK model means you choose your own API endpoint. Your code context does not go to a third-party service by default.

Q: What models does Sylix support? A: Sylix supports connecting to any model via a compatible API endpoint. You bring your own API key and configure the endpoint yourself.

Q: Is there a GitHub repository? A: At time of writing, no public GitHub repository was confirmed. The primary distribution is via the official website at sylixide.com.

Q: How does Verify Loop work? A: When Sylix writes or modifies code, it automatically runs your existing test suite against the changes. If tests pass, the change is confirmed. If tests fail, Sylix iterates on the code until tests pass or you intervene.

Q: Is Sylix funded or backed by an accelerator? A: No funding, Y Combinator, or venture backing was detected on the product page or in the HN launch thread at time of writing.

Conclusion

Sylix is a genuinely different take on the AI code editor category. Being built from scratch in Rust (rather than forked from VS Code) gives it a smaller footprint and a cleaner architectural starting point for local-first, privacy-preserving AI pair programming. The Verify Loop is the most distinctive practical feature — it’s the only editor in this class that ties AI edits directly to your test suite as a verification gate.

If you are looking for a lightweight, native, no-Electron AI editor that keeps your settings from VS Code or Cursor and adds an automatic test-gated workflow, Sylix is worth a look. It is completely free with no account required.

Caveat: Sylix is a new product with a small team. The long-term maintenance trajectory is unknown. Watch the HN launch thread for updates.