New to Hydra?
Hydra Sim Studio is a free Verilog and SystemVerilog simulator that lives inside your editor. You write, simulate and debug your hardware designs without switching to another tool, and Hydra AI is right there to answer questions about your results.
On top of that sit add-ons: optional paid features that teach Hydra new tricks, like writing code from a comment or hunting down race conditions in a simulation. This page explains what Hydra is, how add-ons work, and how to try them before you pay anything.
What is Hydra Sim Studio
Hydra Sim Studio is an editor extension built by RR Logic Systems Pvt. Ltd. for people who design digital hardware. It runs your Verilog and SystemVerilog simulations right next to your code, so the edit, run, inspect loop stays in one window.
It works in VS Code, VS Code Insiders, VSCodium, Cursor and Windsurf. Install it from the Visual Studio Marketplace for VS Code, or from Open VSX for VSCodium, Cursor and Windsurf.
The add-ons
- Code Inject — Describe the change. Hydra writes it into your code.From ₹651.00 · 3 months
- Hydra AI — The RTL assistant, without the local model.From ₹1.00 · Monthly
- Simulation Analysis — Find race conditions before they find you.From ₹651.00 · 3 months
Every add-on has its own page with the full story. Browse the store.
How buying and activation work
- Install the extension in your editor. It is free, and it is where every add-on runs.
- Pick an add-on and a plan on this site. Payment is handled by Razorpay on its own page; we never see your card details.
- Sign in from the extension. It shows a short code and opens hydrasim.ai/activate, where you sign in with Google or Zoho and approve that editor.
- That is it. The add-on appears in your editor on the next refresh. Nothing is downloaded from this website.
Try before you buy
Add-ons that offer a free trial let you use the full thing first. Start the trial from inside the Hydra extension, not from this website: a trial belongs to the device that signs in. A small deposit confirms it and is refunded straight away, so trying costs nothing.
- Code Inject7 days free · ₹1.00 refundable deposit
- Simulation Analysis7 days free · ₹1.00 refundable deposit
FAQs
Is Hydra Sim Studio free?
Yes. The extension is free to install and use. Add-ons are optional paid features that extend it; you only pay for the ones you want.
Which editors does it work in?
VS Code, VS Code Insiders, VSCodium, Cursor, Windsurf. VS Code installs it from the Visual Studio Marketplace; the others install it from Open VSX.
Do I need an account?
Not for the extension itself. You need one for add-ons, so a purchase or a trial can be tied to you. Sign in with Google or Zoho; there is no password to create.
How do I activate an add-on after buying it?
Sign in from the Hydra extension. It shows a short code and opens hydrasim.ai/activate, where you approve the sign-in. The add-on is picked up on the extension's next refresh, with nothing to download from this site.
How does the free trial work?
Start it from inside the Hydra extension, not from this website, because a trial belongs to the device that signs in. A small deposit confirms it and is refunded straight away.
What happens when my plan ends?
The add-on stops loading until you renew. The extension itself keeps working, and buying the add-on again restores it.
Where do I see the devices I am signed in on?
On your Account page, under Devices. Every browser and editor session is listed there, and each one can be signed out.
How do I get help?
Email us at [email protected].