Introduction

AI coding tools are changing the way software is developed. Instead of writing every line of code manually, developers can describe a task in natural language and use an AI coding agent to work with their project.

OpenCode is an open-source, model-agnostic AI coding agent that connects AI models with a development environment. It can work with project files, terminal commands, development tools, and coding workflows.

For example, you can give OpenCode an instruction such as

Create a responsive portfolio website using HTML, CSS, and JavaScript.

OpenCode can then work with the project files and help create the requested website.

You do not need to create a separate AI agent yourself. OpenCode already provides the coding agent workflow.

Source Disclaimer

This article is based primarily on the provided OpenCode source materials, including published guides and reference articles used for this research. 

This guide explains what OpenCode is, how it works, what you can build with it, its key features, supported AI providers, installation, practical usage, pricing, security considerations, comparisons, and a beginner project.

What Is OpenCode?

OpenCode is an open-source coding agent designed to help developers work on software projects.

It is model agnostic, meaning it is designed to work with different AI models and providers instead of being tied to one model.

OpenCode itself is not an AI model such as GPT, Claude, or Gemini. It provides the development environment and tools through which an AI model can interact with a project.

Depending on the configuration, it can work with:

• Project files
• Terminal commands
• Development tools
• Git workflows
• LSP
• MCP
• Project instructions

This makes it possible to use natural language for tasks such as creating features, changing existing code, debugging problems, and working through development tasks.

What Can You Build With OpenCode?

OpenCode can be used for both small projects and larger software development tasks.

Websites

You can ask it to create websites using technologies such as HTML, CSS, JavaScript, React, and other supported technologies.

A prompt could be:

Create a modern responsive portfolio website with a navigation bar, hero section, projects section, contact section, and footer.

You can then continue giving instructions to modify the design or functionality.

Web Tools

OpenCode can help create browser-based tools such as

• Image compressors
• Image converters
• Prompt generators
• Calculators
• Word counters
• JSON formatters
• Unit converters
• Text formatting tools

For example:

Build an image compression tool that allows users to upload an image, choose compression settings, preview the result, and download the compressed file.

Web Applications

It can also assist with applications such as:

• Expense trackers
• Task managers
• Blogging platforms
• Admin dashboards
• Note-takingInventory systems
• Note taking applications
• Authentication interfaces

The final result depends on the project’s technology, structure, instructions, and selected AI model.

Existing Projects

OpenCode can also be used with an existing codebase.

You can ask it to:

• Add functionality
• Fix bugs
• Refactor code
• Improve responsiveness
• Add tests
• Analyze project files
• Improve documentation

How Does OpenCode Work?

The basic workflow is:

Instruction → Project analysis → Code changes → Testing → Improvements

First, you describe the task. OpenCode can then inspect the relevant project files and determine what needs to be changed.

Depending on the task and permissions, it can create or edit files and run development commands.

For example:

Add a dark mode button to the existing website without changing the current layout.

OpenCode can inspect the existing HTML, CSS, and JavaScript and work on the relevant parts of the project.AI-generated license and

You should review and test the resulting changes because AI-generatedlicense, code can contain errors.

OpenCode Features

Open Source

OpenCode is open source and uses the MIT license according to the provided sources.

This allows developers to inspect the project and contribute to it.

Model Agnostic Architecture

OpenCode is designed to work with different AI models rather than requiring one specific model.

This gives developers more flexibility when choosing a provider.

Multiple Providers

The provided sources describe support for more than 75 providers.

Examples include

• Anthropic
• OpenAI
• Google
• DeepSeek
• Groq
• Ollama
• LM Studio

The available providers and models can change over time.

Local Model Support

OpenCode can work with local models through tools such as Ollama and LM Studio.

This can give users more control over where their code and prompts are processed.

Local models can require considerable hardware resources, and smaller models may have difficulty with complex coding tasks.

LSP

OpenCode can use Language Server Protocol, or LSP, to obtain information about code.

It can provide useful diagnostics and language-specific development information, particularly when working with larger codebases.

MCP

Model Context Protocol, or MCP, allows AI systems to interact with additional tools and services.

This can extend the capabilities available to an AI coding workflow.

Plan and Build Modes

OpenCode provides different modes for handling development tasks.

Plan mode can be used to analyze a task and prepare an approach before making changes.

Build mode is used for carrying out development work.

For larger tasks, planning first can make the development process easier to review.

Git Integration

OpenCode can work with Git-based workflows.

The provided sources describe Git snapshots and commands such as:

/undo

and:

/redo

These can help manage changes during development.

For important projects, normal Git commits and backups should still be maintained.

OpenCode Supported Models and Providers

OpenCode is not restricted to one AI model.

The providers mentioned in the provided sources include:

Provider	Example Use
Anthropic	AI coding models
OpenAI	Coding and reasoning models
Google	Gemini models
DeepSeek	Coding and reasoning
Groq	Fast model access
Ollama	Local models
LM Studio	Local model management

The exact models available can change, so users should check the current provider configuration when setting up OpenCode.

How to Install OpenCode

OpenCode can be used across major operating systems.

The provided sources describe installation options for Windows, Linux, and macOS.

Terminal Installation

One installation method described in the provided sources is

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

After installation, start OpenCode with:

opencode

Windows

Install OpenCode on Windows

• Open the official download page.
• Find OpenCode Desktop.
• Select Windows (x64) if you have a normal Intel/AMD Windows PC.
• Download the installer.
• Open the downloaded .exe file.
• Follow the installation instructions.
• Launch OpenCode from the Start Menu.

Linux

• Open Terminal and run:

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

• Then verify the installation:

opencode –version

You can also use the official OpenCode website here:

OpenCode Official Website.

How to Use OpenCode

Once OpenCode is installed, you can use it inside a project directory or folder.

Create or Open a Project

• Open OpenCode from the Windows Start Menu.
• Select or open your project folder.
• Choose/configure an AI model/provider if prompted.
• Type your request in the OpenCode chat, for example:

> Build a responsive website for my project with HTML, CSS and JavaScript.

• Review the changes OpenCode proposes/applies.

So you do not need to manually use CMD or PowerShell if you’re using the desktop version.

Give Specific Tasks

Instead of a simple instruction such as:

Make a website.

provide useful details:

Create a responsive portfolio website using HTML, CSS, and JavaScript.

Include:

1. Navigation bar

2. Hero section

3. About section

4. Skills section

5. Projects section

6. Contact section

7. Footer

Use semantic HTML.

Keep HTML, CSS, and JavaScript in separate files.

Make the website responsive on mobile, tablet, and desktop.

Specific instructions give the coding agent clearer context.

Review and Test

After OpenCode makes changes, check:

• Functionality
• Code structure
• Responsive behavior
• Console errors
• Design
• Security-related settings

If something is wrong, describe the exact problem and ask OpenCode to investigate it.

What Is AGENTS.md?

AGENTS.md is a project instruction file.

It can contain rules that OpenCode should follow while working on a project.

For example:

Project Rules:

Use semantic HTML.

Keep JavaScript in separate files.

Do not use inline CSS.

Make every page responsive.

Use reusable components where possible.

Do not modify the database structure without confirmation.

This is useful when a project has specific coding standards or development rules that should remain consistent.

Practical Beginner Project: Build a To-Do List

A to-do list is a simple project for learning how an AI coding agent works.

We will use HTML, CSS, and JavaScript.

Step 1: Create the Project

Create a folder:

todo-app

Open the folder in your terminal and run:

opencode

Step 2: Give OpenCode the Project Prompt

Use this instruction:CSS,HTML

Create a simple responsive to-do list web app using HTML, CSS and JavaScript.

The app should allow users to:

1. Add a task.

2. Mark a task as completed.

3. Delete a task

4. Display all tasks in a clean interface.

5. Work properly on mobile and desktop screens

Use separate HTML, CSS, and JavaScript files.

Keep the code simple and easy to understand.

A basic project structure can look like this:

todo-app/

│

├── index.html

├── style.css

└── script.js

Step 3: Improve the Interface

After the application works, ask:

Improve the user interface.

• Make the To Do List modern and professional.
• Add better spacing, buttons, a clean card layout, and responsive styling.

Do not change the existing functionality.

Step 4: Add Local Storage

Now add data persistence:

Add localStorage support so that tasks remain saved after the browser is refreshed.

Do not remove the existing add, complete, and delete functionality.

Step 5: Test the Application

Check:

1. Adding a task
2. Completing a task
3. Deleting a task
4. Refreshing the page
5. Saved tasks
6. Mobile layout

If completed tasks lose their state after refreshing, give OpenCode the exact problem:

After refreshing the page, completed tasks are not showing their completed state.

Find the problem in the JavaScript and fix it.

Step 6: Learn From the Generated Code

OpenCode can also explain the project:

Explain this project to me as a beginner.

style.css,style.css,

Explain what index.html, style.css and script.js do.

Then explain how localStorage is being used.

This makes the project useful for learning as well as development.

Step 7: Extend the Project

After the basic version works, you can add features such as:

• Dark mode
• Task counter
• Search
• Filters
• Due dates
• Categories
• Priority levels
• Clear completed button

More Project Ideas

After completing a small project, you can experiment with:

Portfolio Website

Create a personal website containing your skills, projects, services, and contact information.

Calculator

Build a responsive calculator with HTML, CSS, and JavaScript.

Expense Tracker

Create an application for recording and categorizing expenses.

Image Compressor

Build a browser-based tool for compressing and downloading images.

Prompt Generator

Create a tool that generates AI prompts from user input.

Blog Website

Build a blog interface with posts, categories, search, and responsive layouts.

Admin Dashboard

Create a dashboard containing statistics, tables, charts, navigation, and settings.

Is OpenCode Free?

The OpenCode software itself is open source and free to use according to the provided sources.

However, the AI model or provider can have separate costs.

There are two different things to consider:

OpenCode Software

The OpenCode software is open source.

AI Model Costs

A hosted provider may require an API account, subscription, or usage-based payment.

A local model may avoid external API charges, but running it requires suitable computer hardware.

Is OpenCode Safe?

The level of risk depends partly on the permissions and tools available to the coding agent.

Depending on its configuration, OpenCode may be able to:

• Read project files
• Modify files
• Run commands
• Access development tools
• Work with external services

Review important changes before accepting them.

Extra care is appropriate when working with:

• Production systems
• Private repositories
• API keys
• Databases
• Authentication systems
• Financial applications

Do not unnecessarily expose passwords, private keys, or other sensitive credentials.

Can OpenCode Run Locally?

Yes. OpenCode can work with local AI models through tools such as Ollama and LM Studio.

A local setup can provide greater control over where code and prompts are processed.

However, local model use does not automatically mean that every part of the development environment is isolated.

You should understand the model and configuration you are using.

Hardware requirements can also vary considerably between models.

OpenCode vs. Claude Code vs. Cursor vs. Cline

These tools provide different approaches to AI-assisted software development.

Feature	OpenCode	Claude Code	Cursor	Cline
Open source	Yes.	No	No	Yes.
Model flexibility	High	More focused	Multiple models	Multiple models
Terminal workflow	Yes.	Yes.	Available	Available
Local models	Supported	More limited	Depends on setup	Supported
IDE experience	Terminal and integrations	Terminal-focusededTerminal-focused	IDE-focused	IDE-focused
Git workflow	Supported	Supported	Supported	Supported
MCP	Supported	Supported	Supported	Supported

The main differences involve their interfaces, architecture, model ecosystems, and development workflows.

Who Should Use OpenCode?

OpenCode can be useful for:

• Web developers
• Software developers
• Programming students
• Developers working with large codebases
• Developers interested in local AI
• Developers who want model flexibility
• Developers interested in open-source coding tools

Beginners can also use it for small projects. Basic programming knowledge is useful because it allows you to understand, test, and review generated code.

How to Get Better Results From OpenCode

Good instructions give the AI coding agent useful context.

Instead of:

Fix my website.

Describe the problem:

• The mobile navigation menu does not open when the menu button is clicked.
• Inspect the HTML, CSS, and JavaScript.
• Find the cause.
• Fix only the navigation problem.
• Do not change the desktop layout.

Then explain what you changed.

For larger applications, divide the work into smaller tasks.

A useful workflow is

Plan → Build → Test → Review → Fix → Improve

Frequently Asked Questions

Conclusion

OpenCode provides an open-source approach to AI-assisted software development. Its model-agnostic design allows developers to work with different AI providers and supported models.

It can assist with websites, web tools, applications, debugging, refactoring, testing, and existing codebases.

For beginners, a small project such as a to-do list is a practical way to understand the workflow. You can start with a simple feature, test it, and gradually add more functionality.

The most important thing is to give clear instructions, provide enough project context, review generated changes, and test the final result.