Getting to Know Grok Code Fast 1: The Lightning-Fast AI Coding Assistant from xAI

If you're a developer, you're probably already familiar with various AI coding assistants like GitHub Copilot, Cursor, or Claude. But have you ever felt frustrated by slow AI responses, especially when you're in a rapid iteration phase? Or maybe you're worried about costs ballooning due to high token usage?

Well, xAI has an interesting solution for these problems. They've just launched Grok Code Fast 1, an AI model specifically for coding that claims to be 4x faster and 10x cheaper than its competitors. Sounds interesting, right?

In this article, we'll discuss everything about Grok Code Fast 1, from what it actually is, its standout features, to how to use it directly in VS Code using Kilo Code or Cline. Let's get started!

What is Grok Code Fast 1?

Grok Code Fast 1 is an AI reasoning model specifically designed for agentic coding workflows. Officially launched in August 2025, this model was built from scratch with a new architecture optimized for day-to-day programming tasks.

Unlike general-purpose AI models like ChatGPT or Claude that were then adapted for coding, Grok Code Fast 1 was indeed created from the start to help developers write, debug, and understand code faster and more efficiently.

The word "Grok" itself comes from the science fiction novel "Stranger in a Strange Land" which means to understand something deeply and intuitively. This name reflects xAI's goal to create an AI assistant that truly understands the coding context comprehensively.

Why Choose Grok Code Fast 1?

Before we dive into the installation and usage tutorial, let's discuss what advantages make Grok Code Fast 1 worth trying.

Genuinely Fast Speed

Imagine you're coding and asking for AI help, then you have to wait 5-10 seconds for a response. Sometimes we lose momentum, right? Well, Grok Code Fast 1 can generate 92 tokens per second. That means its response is almost instant!

This speed isn't just about numbers, but really changes how you work. You can give small tasks, get results quickly, evaluate, then iterate again. The workflow becomes more dynamic and interactive.

Massive Context Window

Grok Code Fast 1 has a context window of 256,000 tokens. This means it can "see" and understand very large codebases at once. So if you have a project with hundreds of files, it can still maintain consistency and understand the relationships between files well.

Have you ever used an AI coding assistant and it forgets the context you gave it earlier? Well, with a context window this large, that problem can be minimized.

Very Affordable Pricing

Now, this is what makes Grok Code Fast 1 attractive. xAI offers very competitive pricing:

• $0.20 per 1 million input tokens
• $1.50 per 1 million output tokens
• $0.02 per 1 million cached input tokens

For perspective, this is about 10x cheaper than other leading agentic coding models. So if you're an individual developer or startup with a limited budget, this can be a very economical choice.

Transparent Reasoning Traces

One unique feature of Grok Code Fast 1 is that it displays reasoning traces or its thought process. So you can see how the AI arrived at the conclusion or solution it provides.

This is very helpful especially during debugging or when AI results don't match expectations. You can see where the AI's "train of thought" went off track, and guide it in the right direction.

Optimized for Agentic Workflows

Grok Code Fast 1 was designed from the start for agentic coding workflows, which is a workflow where AI doesn't just provide suggestions, but actively uses tools like:

• Grep for searching in codebases
• Terminal commands to run commands
• File editing to modify files
• And other tools

xAI also collaborated directly with launch partners like Cursor, Cline, and Kilo Code during development, ensuring this model works optimally in the tools developers already use.

Instantly Dominated OpenRouter

Now, this makes Grok Code Fast 1 even more interesting. Just within one week after launch, Grok Code Fast 1 immediately dominated the #1 position on the OpenRouter leaderboard for the programming category!

OpenRouter is an AI model aggregator platform serving hundreds of thousands of developers worldwide. The latest data shows that Grok Code Fast 1 has been used for 1.19 Trillion tokens in one week, beating other major models like:

• Claude Sonnet 4.5 (557B tokens)
• Gemini 2.5 Flash (286B tokens)
• Claude Sonnet 4 (163B tokens)
• And other models

This isn't just about numbers. Grok Code Fast 1's dominance on OpenRouter shows that developers worldwide are actually using it for their daily work. The combination of speed, low price, and solid performance makes this model immediately become a favorite in the developer community.

Imagine, in less than a week, this model has already processed more than 1 trillion tokens! This is real proof that Grok Code Fast 1 isn't just hype, but truly delivers value for developers.

How Good is Its Performance?

OK, we've discussed its features. Now the question is: how good is Grok Code Fast 1's performance?

SWE-Bench-Verified Benchmark

On the SWE-Bench-Verified benchmark (one of the standard benchmarks for measuring AI capabilities in software engineering), Grok Code Fast 1 scored 70.8%. This figure shows solid capability in completing real-world software engineering tasks.

Although benchmarks are important, xAI also emphasizes that they focus on performance in real-world usage, not just chasing benchmark numbers. That's why they also conduct direct evaluations with developers to ensure this model is truly useful in daily work.

Supported Programming Languages

Grok Code Fast 1 is very proficient in various popular programming languages, including:

• TypeScript
• Python
• Java
• Rust
• C++
• Go

So whatever technology stack you use, chances are Grok Code Fast 1 can help you well.

Model Architecture

For those curious about the technical details, Grok Code Fast 1 uses a mixture-of-experts (MoE) architecture with an estimated 314 billion parameters. This architecture enables optimal balance between speed and capability, so it can be fast yet still powerful.

How to Use Grok Code Fast 1

Now, we get to the most important part: how to use Grok Code Fast 1? There are several ways you can choose, but in this article we'll focus on the two most popular methods: using Kilo Code and Cline in VS Code.

Prerequisites

Before continuing, make sure you already have:

• Visual Studio Code installed on your computer
• Stable internet connection
• (Optional) xAI API Key if you want to use your own API after the free period ends

Method #1: Using Kilo Code

Kilo Code is a free open-source AI coding extension for VS Code that has been downloaded more than 250,000 times. Through partnership with xAI, Kilo Code offers free access without rate limits to Grok Code Fast 1.

Step #1: Install Kilo Code Extension

Open your VS Code, then:

1. Click the Extensions icon in the left sidebar (or press Ctrl+Shift+X)
2. Type "Kilo Code" in the search box
3. Click the Install button on the Kilo Code extension
4. Wait until the installation process completes

Step #2: Update to Latest Version

If you've installed Kilo Code before, make sure you update to version 4.83.1 or newer. This version already supports Grok Code Fast 1.

To update, just click the Update button in Extensions if a new version is available.

Step #3: Configure Grok Code Fast 1

After Kilo Code is installed, follow these steps:

1. Open Settings in VS Code (File → Preferences → Settings or Ctrl+,)
2. Search for "Kilo Code" in the search bar
3. Or you can directly click the Kilo Code icon in the sidebar then select Settings
4. In the Providers section, select Kilo Code
5. In the Model dropdown, select 'x-ai/grok-code-fast-1'

Done! Now Kilo Code is using Grok Code Fast 1 as its AI model.

Step #4: Test Grok Code Fast 1

Let's test if our setup is correct:

1. Open any code file (for example a JavaScript or Python file)
2. Type a comment like // create a function to calculate factorial
3. Press Enter and wait for suggestions from Grok Code Fast 1
4. Or use the Kilo Code command palette to give more complex instructions

If everything runs smoothly, you'll get very fast responses from Grok Code Fast 1!

Benefits of Using Kilo Code

• Free access without rate limits (during launch period)
• Open-source and free forever
• Zero markup from API costs
• Can use your own API key (BYOK) if you want
• Active community with 250,000+ users

Method #2: Using Cline

Cline (formerly known as Claude Dev) is another popular AI coding assistant extension that's also a Grok Code Fast 1 launch partner.

Step #1: Install Cline Extension

Open your VS Code, then:

1. Click the Extensions icon in the left sidebar
2. Type "Cline" in the search box
3. Click the Install button on the Cline extension
4. Wait until the installation process completes

Step #2: Update to Latest Version

Make sure you're using the latest version of Cline that already supports Grok Code Fast 1. If there's an update, click the Update button.

Step #3: Configure Grok Code Fast 1 in Cline

After Cline is installed:

1. Click the Cline icon in the VS Code sidebar
2. The Cline panel will appear in the sidebar
3. Click the Settings icon (gear icon) in the Cline panel
4. In the Model section, click the dropdown and search for 'grok-code-fast-1'
5. Select that model
6. Click Save or Apply

Step #4: Start Coding with Cline

Cline has several modes you can use:

1. Chat Mode: For asking about code or requesting suggestions
2. Agent Mode: For more complex tasks where Cline can use tools
3. Edit Mode: For modifying existing files

Try opening your code file, then type a question in the Cline panel. For example:

Please create a function for email validation with regex

Grok Code Fast 1 will respond very quickly!

Benefits of Using Cline

• User-friendly interface
• Autonomous agent mode for complex tasks
• Multi-file editing capabilities
• Direct collaboration with xAI during development
• Special optimization for Grok Code Fast 1

Other Methods

Besides Kilo Code and Cline, Grok Code Fast 1 is also available on other platforms:

GitHub Copilot

If you're a GitHub Copilot subscriber (Pro, Pro+, Business, or Enterprise), you can enable Grok Code Fast 1:

1. Open VS Code
2. Click the GitHub Copilot icon in the status bar
3. Select Model Picker
4. Select Grok Code Fast 1 from the model list

Free access is available until September 2, 2025.

Cursor

Cursor is an AI-powered code editor based on VS Code. Grok Code Fast 1 is already integrated directly:

1. Download and install Cursor from the official website
2. Open Settings
3. Select Grok Code Fast 1 as the model
4. Start coding!

Other Platforms

• Roo Code: AI coding assistant
• opencode: Open-source coding platform
• Windsurf: Codeium's AI-integrated IDE
• Direct API Access: Through https://api.x.ai for custom integrations

Tips for Maximum Results

OK, setup is complete. Now, how do you use Grok Code Fast 1 to get maximum results? xAI has compiled a Prompt Engineering Guide specifically for Grok Code Fast 1. Let's discuss the tips:

Tip #1: Provide Specific Context

Don't give instructions that are too general. The more specific context you provide, the better the results.

Less Good Example:

Fix bugs in this file

Good Example:

My error codes are defined in @errors.ts.
Please add proper error handling to @sql.ts
using existing error codes,
specifically for all database queries

See the difference? The second one is much more specific and provides clear context.

Tip #2: Clearly Define Goals

Explain in detail what you want to achieve. Don't assume the AI knows what you want.

Example:

I want to refactor the getUserData() function to:
1. Use async/await instead of callbacks
2. Add proper error handling
3. Add caching to reduce database calls
4. Remain backward compatible with existing code

Tip #3: Rapid Iteration with Small Tasks

This is important! Because Grok Code Fast 1 is very fast, you should give tasks in small chunks, then iterate quickly.

Don't do this:

Build me a complete e-commerce website
with user authentication, product catalog,
shopping cart, payment gateway, admin panel,
inventory management, and email notifications

Better like this:

Task 1: Create database schema for product catalog
(wait for results, evaluate)

Task 2: Create API endpoint for get all products with pagination
(wait for results, evaluate)

Task 3: Create API endpoint for get product by ID
(and so on...)

This way, you can ensure each step meets expectations before moving to the next step.

Tip #4: Utilize for Agentic Tasks

Grok Code Fast 1 is designed for agentic workflows. So don't hesitate to give tasks that require:

• Grep: Searching in codebases
• File editing: Modifying multiple files
• Terminal operations: Running commands
• Multi-step reasoning: Tasks that need several steps

Example:

Find all functions using old API endpoint "/api/v1/users",
then update to new endpoint "/api/v2/users",
and make sure all tests still pass

Tip #5: Use for High-Volume Tasks

Because Grok Code Fast 1's price is very cheap, it's ideal for repetitive or high-volume tasks:

• Routine debugging
• Automated code review
• Large-scale refactoring
• Adding error handling to many files
• Documentation generation
• Unit test creation

Tip #6: Quick Feedback Loop

If the first result isn't perfect, don't get frustrated. Take advantage of Grok Code Fast 1's speed for quick iterations:

Example:

User: Create a function to sort array of objects by name

Grok: [provides code]

User: Good! But please add case-insensitive sorting

Grok: [provides improved code]

User: Perfect! Now please add option for reverse order

Grok: [provides final version]

This process can be very quick because of Grok Code Fast 1's almost instant response time.

What's Coming Next?

What's interesting about Grok Code Fast 1 is that xAI is committed to continuously developing it very quickly. This isn't a product that's launched and then abandoned, but will be continuously updated and improved.

Updates in Days

xAI promises to make updates in days, not weeks. And they've already proven it! Before the official launch, they already did a soft launch with the codename "Sonic" and deployed several new checkpoints based on community feedback.

So if you find bugs or have improvement suggestions, chances are they'll be addressed quickly.

New Features Already in Training

xAI announced that they're already training a new variant of Grok Code Fast 1 with additional features:

• Multimodal Inputs: Imagine you could debug based on screenshots or diagrams. Cool, right?
• Parallel Tool Calling: Can execute multiple operations concurrently, so it's even faster
• Extended Context Length: Context window larger than the current 256K tokens

These features seem like they'll be available soon.

Healthy Competition

The launch of Grok Code Fast 1 makes competition in AI coding assistants increasingly fierce. There's OpenAI with GPT models, Anthropic with Claude, Google with Gemini, and now xAI with Grok.

This competition is good for us as developers, because:

• Prices become more competitive
• More and more features
• Quality continues to improve
• We have many choices according to needs

Real-World Usage Examples

Theory is enough. Now let's look at real examples of how developers use Grok Code Fast 1 in their projects.

Case Study #1: Building a Game Prototype in One Day

A developer successfully created a complete battle simulator prototype in less than a day using Grok Code Fast 1 in Cursor.

The workflow he used was very interesting:

1. Planning Phase: Asked Grok Code Fast 1 to create a big plan for his game
2. Break Down: Split the big plan into small tasks per feature
3. Rapid Iteration: Execute tasks one by one with rapid iteration
4. Refinement: Polish each feature until it meets expectations

What's interesting is that because of Grok Code Fast 1's speed, he could get almost instant feedback for each task. So the process became very smooth and productive.

Case Study #2: JavaScript to TypeScript Migration

Another developer used Grok Code Fast 1 for a quite challenging task: convert an entire JavaScript codebase to TypeScript.

The process:

1. Asked Grok Code Fast 1 to convert files one by one
2. The model didn't just convert syntax, but also:
   • Maintained proper TypeScript conventions
   • Handled terminal interactions (detected when pnpm wasn't installed)
   • Preserved /dist file structure
   • Set up TypeScript config correctly

The result? Perfect migration without breaking any components! UI stayed the same, but now using TypeScript with complete type safety.

Case Study #3: Aviation Instrument Simulator

There was a developer who tested Grok Code Fast 1's capabilities with a complex project: creating an "Aviation Instrument 6-Pack" simulation with detailed requirements:

• Vertical speed indicator
• Altimeter
• Turn coordinator with plane icon
• Earth speed indicator with marked stall speed
• Magnetic north indicator
• Artificial horizon

Not stopping there, he also requested more complex enhancements:

• Add slip/skid indicators to turn coordinator
• Preserve existing class inheritance hierarchy
• Maintain public/private method signatures

Grok Code Fast 1 succeeded with precision modifications. Even when asked to enhance the turn coordinator while preserving existing architecture, no other components broke. Impressive!

Comparison with Competitors

Before the conclusion, let's look at a quick comparison between Grok Code Fast 1 and its main competitors:

From the table above, Grok Code Fast 1's advantages in speed and price are clearly visible.

Conclusion

Based on the discussion in this article, it can be concluded that Grok Code Fast 1 is a very promising AI coding assistant, especially for developers who want speed and cost efficiency.

With a speed of 92 tokens per second, 256K token context window, and very competitive pricing, Grok Code Fast 1 offers a value proposition that's hard to ignore. Plus with free access through Kilo Code and Cline, this is the right time to try it.

What's most interesting is that Grok Code Fast 1 was built from scratch specifically for agentic coding workflows, not a general-purpose model that was adapted. This makes its performance very optimal for day-to-day coding tasks.

Key Takeaways

• Speed: 92 tokens/sec, almost instant
• Economical: 10x cheaper than competitors
• Large Context: 256K tokens for large codebases
• Easy Access: Free via Kilo Code and Cline in VS Code
• Transparent: Visible reasoning traces
• Continuously Evolving: Updates in days

Who Should Use It?

Grok Code Fast 1 is perfect for:

• Developers who want to increase productivity
• Teams with limited budgets
• Those frustrated with slow AI responses
• Developers working with large codebases
• Anyone curious about the future of AI-assisted development

Next Steps

Now it's your turn to try! It's easy:

1. Install Kilo Code or Cline in your VS Code
2. Setup Grok Code Fast 1 as the model (follow the tutorial above)
3. Start with simple tasks to get familiar with the model
4. Explore and experiment with various use cases
5. Provide feedback to xAI for improvement

With the limited free period and multimodal updates coming soon, now is the right time to try if Grok Code Fast 1 can transform your coding workflow.

Happy coding! 🚀

Resources and Useful Links

For more information, you can visit the following links:

• xAI Official: https://x.ai/news/grok-code-fast-1
• Documentation: https://docs.x.ai/docs/models/grok-code-fast-1
• Prompt Engineering Guide: https://docs.x.ai/docs/guides/grok-code-prompt-engineering
• Kilo Code Extension: Search for "Kilo Code" in VS Code Marketplace
• Cline Extension: Search for "Cline" in VS Code Marketplace
• xAI API: https://api.x.ai

If you found this article helpful, don't forget to share it with your fellow developers. If you have questions or experiences using Grok Code Fast 1, please share them in the comments!

Hope this article helps. 👨‍💻