How to Use AI in Visual Studio Code for Free — No Paid API Keys Needed

Want to use AI-powered coding assistance in Visual Studio Code but don’t want to pay for API keys? You’re not alone. Many developers assume AI coding tools require expensive subscriptions, but there are actually three completely free ways to use AI in VS Code — all using Open Code CLI under the hood.

In this tutorial, I’ll show you how to set up AI in Visual Studio Code using three different free providers: Open Code Zen, OpenRouter, and Groq. You can switch between them when one reaches its limit — giving you unlimited AI coding access for free.

What You’ll Learn

By the end of this guide, you’ll have:

AI-powered code generation directly inside VS Code — for free
Three backup providers so you never hit a rate limit
A working Flask app built entirely with AI in under 1 minute
The ability to switch between providers with a single command

All three methods use Open Code CLI — a free command-line tool that connects VS Code to various AI providers. Think of it as a bridge between your editor and free AI models.

Want to skip reading? Watch the full tutorial below

Tools & Requirements

Tool	Purpose	Cost
Visual Studio Code	Code editor	Free
Open Code CLI	AI coding bridge	Free
Open Code Zen	Free AI provider (5 models)	Free
OpenRouter	Free AI provider (many models)	Free
Groq	Free AI provider (Gemini)	Free
Node.js	Required for Open Code CLI	Free

No credit card. No paid subscriptions. Completely free forever.

Why Three Providers?

Here’s the problem with relying on a single free AI provider: rate limits. Free tiers have daily or monthly request caps. When you hit that limit, you’re stuck until the next day.

The solution? Register all three providers and cycle between them:

Open Code Zen — 5 free models, generous limits
OpenRouter — Many free models (Llama, Gemma, etc.)
Groq — A few free models

When one provider’s limit is reached, simply switch to the next one with a single command. You’ll never be blocked from using AI coding again.

Step 1: Install Open Code CLI

Open Code CLI is the bridge that connects VS Code to AI providers. Install it via npm:

If you’re on Windows, open Command Prompt and run:

npm i -g opencode-ai

Or if you’re on Linux, open Terminal and run:

curl -fsSL https://opencode.ai/install | bash

This will install Open Code CLI globally on your system. It may take a minute or two.

Verify installation:

Run this command in your terminal to verify that OpenCode has been successfully installed.

opencode --version

Step 2: Install the Open Code Extension in VS Code

Now let’s connect VS Code to Open Code CLI:

Open Visual Studio Code
Go to Extensions (Ctrl+Shift+X)
Search for “Open Code”
Install the extension by SST (the official one)
Trust the publisher and install

Once installed, you’ll see the Open Code icon in your sidebar. Click it to open the AI chat panel.

Step 3: Set Up Provider #1 — Open Code Zen (5 Free Models)

Open Code Zen gives you access to 5 free AI models directly — no account needed on a separate platform.

Generate Your Open Code Zen API Key:

Go to Open Code Zen
Click “Get Started with Zen”
Sign in with Google or GitHub
Click on “Create API Key”
Give the API key a name and select an expiration period, and generate
Copy the generated API key

Connect to VS Code:

In VS Code, type /connect in the Open Code chat
Select Open Code Zen as the provider
Paste your API key
Press Enter

Available Free Models

The following free models are available from Open Code Zen at the time of publishing this article:

Model	Best For
Big Pickel	General coding tasks
DeepSeek V4 Flash Free	Advanced reasoning
Mimo V2.5 Free	Fast code generation
Nimotron 3 Ultra Free	Complex programming
North Mini Code Free	Lightweight tasks

That’s 5 free models ready to use — no payment required.

Step 4: Set Up Provider #2 — OpenRouter (Many Free Models)

OpenRouter is a gateway to dozens of AI models, many of which are completely free.

Generate Your OpenRouter API Key:

Go to OpenRouter
Create an account (or sign in with Google)
Go to “Get API Key” from the home page or open your profile and click on the “API Keys” in the left sidebar
Click “New Key”
Give the key a name
Leave Credit Limit blank (unlimited)
Set Expiration to suite your requirements
Click Create and copy the key

Connect to VS Code:

In VS Code, type /connect in the Open Code chat
Search for and select OpenRouter
Paste your API key
Press Enter

Available Free Models on OpenRouter:

Model	Parameters	Best For
Llama	Variable Parameters	Great for programming
GPT-OSS	Variable Parameters	General AI tasks
Gemma 4	31B params	Powerful open model

OpenRouter offers many more free models — you’ll always have a backup option.

Step 5: Set Up Provider #3 — Groq

Groq also provides free access to some models.

Generate Your Groq API Key:

Go to Groq
Create an account
Click “Start Building” (top right)
Click “API Keys” (top right)
Click “Create API Key”
Give it a name and set expiration to 7 days (or longer), or as per your requirements
Click Submit and copy the key

Connect to VS Code:

In VS Code, type /connect in the Open Code chat
Search for and select groq
Paste your API key
Press Enter

Now you have access to Groq’s models — all within VS Code.

Step 6: Switch Between Providers (The Secret Sauce)

Here’s where the magic happens. When you hit a rate limit on one provider, switch instantly:

/connect

Then select a different provider. Your chat history stays intact, and you can continue coding without interruption.

Pro tip: If Open Code Zen is rate-limited, switch to OpenRouter. If OpenRouter is slow, switch to Groq. You’ll never be blocked from using AI coding.

Step 7: Test It Out — Build a Flask App in Less Than 1 Minute

Let’s put this setup to the test. Open a new folder in VS Code and ask the AI:

> “Please create an expense tracking Flask app”

In under 1 minute, the AI generated:

A complete Flask project structure
Database models for expenses and categories
Templates for the web interface
app.py with all routes configured
Categories: Food, Transport. Entertainment, Other.

The AI built a fully functional expense tracker — complete with forms, database, and navigation. And it was done in under a minute, completely free.

Use Cases: Who Should Use This?

Students: Get AI coding help without paying for GitHub Copilot or ChatGPT Plus
Freelancers: Use AI to speed up development without eating into your profit margin
Junior Developers: Learn faster with AI explanations and code generation
Side Project Builders: Rapidly prototype ideas without API costs
Anyone on a Budget: Professional AI coding assistance at zero cost

Why Free? Why Three Providers?

I built this tutorial because I believe AI coding tools should be accessible to everyone — not just those who can afford $20/month subscriptions. Here’s the reality:

Open Code Zen gives you 5 models for free — no account juggling
OpenRouter aggregates dozens of free models in one place
Groq gives you access to some of Groq’s AI Models for free

By cycling between these three, you get unlimited AI coding without paying a single cent. And because they all use the same Open Code CLI interface, switching takes just seconds.

Tips for Best Results

Start with Open Code Zen — it’s the simplest setup with 5 free models
Register all three providers upfront so you can switch instantly when needed
Use specific prompts — “Create a Flask expense tracker with categories” works better than “build an app”
Check model names on the left side — the left shows the model name, right shows the provider
Set context to “Max” when testing — this gives the AI more context about your project
Use /connect to switch — it’s the fastest way to cycle between providers
Keep your API keys safe — paste them only into the Open Code chat, never share them

Frequently Asked Questions

Q: Is this really completely free?

A: Yes. All three providers (Open Code Zen, OpenRouter, Groq) offer free tiers with generous limits. No credit card required.

Q: Do I need to install Python or Node.js separately?

A: You need Node.js installed for Open Code CLI (npm i -g opencode-ai). Python is only needed if you run Python code — not for the AI setup itself.

Q: What happens when I hit a rate limit?

A: Simply type /connect and switch to a different provider. The cycle between all three gives you virtually unlimited access.

Q: Can I use this on Mac or Linux?

A: Yes! Open Code CLI works on Windows, Mac, and Linux. The setup is identical across all platforms.

Q: Which provider should I use first?

A: Start with Open Code Zen — it has 5 free models and requires the least setup. Then register OpenRouter and Groq as backups.

Q: Is the code quality good enough for real projects?

A: Absolutely. The free models (especially Deep Seek and Llama) produce production-quality code. You may need to tweak some outputs, but it’s a massive time-saver.

Q: Can I use this alongside GitHub Copilot?

A: Yes. Open Code works independently of Copilot. You can use both simultaneously or switch between them.

Key Takeaways

AI coding in VS Code is free — using Open Code CLI with three providers
Three backup providers ensure you never hit a rate limit
Open Code Zen gives you 5 free models instantly
OpenRouter provides access to Llama, Gemma, and more free models
Groq gives you some of Groq’s AI Models for free
Switch between providers with a single /connect command
Build real projects — the Flask expense tracker was built in under a minute

Try It Out

Ready to set up free AI coding in VS Code? Here’s your checklist:

Install Open Code CLI: npm i -g opencode-ai
Install the Open Code extension in VS Code
Register Open Code Zen → get API key → connect
Register OpenRouter → get API key → connect
Register Groq → get API key → connect
Start coding with AI — for free!