OpenCode Complete Guide: 2026 Best Open Source Terminal AI Coding Assistant

Q: Is OpenCode completely free?

Yes, 100% free and open source. You only pay for AI models you connect to it, or use free local models via Ollama.

Q: How does OpenCode compare to Cursor?

OpenCode runs in your terminal and is free/open source. Cursor is a full GUI editor with freemium pricing.

Q: Does OpenCode support local AI models?

Yes. It works with Ollama, LM Studio, and 75+ LLM providers. Run models locally for full privacy.

Q: Can OpenCode automate Git commits?

Yes. It can read your codebase, make changes, and commit to Git automatically with configurable approval settings.

Why is OpenCode Worth Attention?

In the 2026 AI coding tool landscape, OpenCode has emerged as a dark horse. This fully open source terminal AI coding assistant gathered 120k+ GitHub stars in just a few months, serving over 5 million developers monthly.

Unlike closed-source alternatives, OpenCode's core philosophy is: your code should stay on your machine. It supports 75+ LLM providers, including Claude, GPT, Gemini, and even local models via Ollama, truly enabling zero-cost AI coding.

Core Advantages

Feature	Description
100% Open Source	No hidden fees, no subscriptions, no tricks
Provider Neutral	Supports Claude, GPT, Gemini, local models, 75+ providers
Terminal Native	Beautiful TUI (Terminal User Interface), never leave the command line
IDE Integration	Seamless collaboration with VS Code, Cursor, Zed, and any terminal-supporting IDE
GitHub Integration	Automate tasks directly in Issue and PR comments
Privacy First	Stores no code or context data

Quick Start: 30-Second Installation

Method One: One-Click Install (Recommended)

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

Method Two: Package Manager

macOS (Homebrew):

brew install opencode

Windows (Scoop):

scoop install opencode

npm/bun:

npm i -g opencode-ai@latest
# or
bun add -g opencode-ai

Method Three: Desktop App

Visit opencode.ai/download to download the native desktop app, suitable for users who prefer not to use the terminal.

Initial Configuration: Choose Your AI Model

OpenCode's power lies in its flexibility. You can choose any LLM provider you prefer:

Recommended Options

Provider	Use Case	Cost
OpenCode Zen	Official curated models, coding-optimized	Pay-per-use
OpenAI GPT	Familiar choice for ChatGPT users	$0.01-0.03/1K tokens
Google Gemini	Excellent for multimodal tasks	Generous free tier
Ollama Local Models	Privacy-sensitive, zero cost	Completely free

Configure API Key

Create global config file ~/.config/opencode/opencode.json:

{
  "provider": "openai",
  "model": "gpt-4o"
}

Or set environment variables:

export OPENAI_API_KEY="your-api-key-here"
export ANTHROPIC_API_KEY="your-api-key-here"
export GOOGLE_API_KEY="your-api-key-here"

Launch OpenCode

cd /path/to/your/project
opencode

You'll see a beautiful terminal interface, ready to help you code!

Core Concepts: Plan Mode vs Build Mode

OpenCode has two working modes, switchable via Tab key:

🧠 Plan Mode (Read-Only)

Cannot modify code - Safely explore the codebase
Analyze and understand - Map project structure and logic
Develop strategy - Propose implementation plans
Use case: Understanding unfamiliar codebases, planning complex features

🔨 Build Mode (Default)

Full access - Read, write, modify files
Execute changes - Actually write and refactor code
Run commands - Execute tests, builds, etc.
Use case: Daily development, feature implementation

Pro Tip: When handling complex features, always plan first in Plan mode, then switch to Build mode to implement. This avoids costly mistakes.

Essential Commands Quick Reference

Command	Description
`/undo`	Undo last change
`/redo`	Redo undone changes
`@`	Fuzzy search files in the project
`Tab`	Switch Plan/Build mode
`Cmd+Esc` (Mac)	Open OpenCode in IDE split view
`Ctrl+Esc` (Win/Linux)	Open OpenCode in IDE split view

Practical Examples

Example 1: Understanding a Codebase

You: Explain the authentication flow in this project

OpenCode will analyze relevant files and provide a detailed explanation of the authentication mechanism,
including middleware, session management, and security policies.

Example 2: Adding a Feature

You: Add a dark mode toggle button on the settings page

OpenCode will:
1. Find the settings page component
2. Identify the theme system
3. Implement the toggle logic
4. Update relevant style files

Example 3: Debugging

You: The login form won't submit. Error: [paste error]

OpenCode will trace the issue to the root cause, which may be:
- Event listener not properly bound
- Form validation logic incorrect
- API endpoint misconfigured

Example 4: Code Refactoring

You: Refactor the UserService class to use dependency injection

OpenCode will modernize your code structure while maintaining functionality.

Create an AGENTS.md File

For best results, create an AGENTS.md file at the project root:

## Project: My SaaS App

## Tech Stack
- Next.js 14 with App Router
- TypeScript
- Tailwind CSS
- PostgreSQL with Prisma

## Coding Standards
- Use functional components
- Use server components where possible
- Follow REST API naming conventions
- Write tests for new features

## Project Structure
- /app - Next.js app router pages
- /components - Reusable UI components
- /lib - Utility functions and helpers
- /prisma - Database schema and migrations

This file helps OpenCode understand your project conventions and preferences.

IDE Integration

VS Code / Cursor

Open terminal in IDE
Run opencode
Press Cmd+Esc (Mac) or Ctrl+Esc (Win/Linux) to open in split view

Non-Interactive Mode

For scripts and automation:

opencode -p "Explain the use of context in this Go project"

This processes your prompt, prints the result, and exits.

GitHub Integration

OpenCode can run directly in your GitHub workflows:

Mention /opencode or /oc in an Issue or PR comment
OpenCode runs in a GitHub Actions runner
Creates a new branch and submits a PR

Example comment:

/opencode Fix the bug described in this issue

Free Model Options

OpenCode offers several free models:

Grok Code Fast 1 - Limited-time free (feedback collection period)
GLM 4.7 - Limited-time free
Big Pickle - Stealth model, limited-time free

Combined with Ollama local models, you can achieve truly zero-cost AI coding.

Important Notes

⚠️ Important: Anthropic blocked OpenCode from using Claude models in January 2026. If you need Claude-level code quality, use GPT-4o or Gemini 2.5 Pro as alternatives.

Summary

OpenCode represents an important trend in 2026 AI coding tools: open source, flexible, privacy-first. Whether you want to try AI coding at zero cost or need to work in a privacy-sensitive environment, OpenCode is a choice worth considering.

Quick Decision Guide

Beginners: Start with GitHub Copilot Free to familiarize with the workflow
Terminal enthusiasts: OpenCode + Ollama local models
Professional developers: OpenCode + GPT-4o/Claude (via official API)
Privacy-sensitive: OpenCode + local Ollama models

Related links:

FAQ

What is OpenCode CLI?

OpenCode is an open-source terminal AI coding assistant with 120k+ GitHub stars. It lets you use AI to generate, edit, and debug code directly from your command line.

Is OpenCode completely free?

Yes. OpenCode is 100% free and open source. You only pay for the AI models you connect to it — or use free local models via Ollama for zero-cost AI coding.

How does OpenCode compare to Cursor?

OpenCode runs in your terminal and is completely free/open source. Cursor is a full GUI editor with a freemium pricing model. OpenCode is ideal for terminal lovers; Cursor is better for visual editing.

Does OpenCode support local AI models?

Yes. OpenCode works with Ollama, LM Studio, and any OpenAI-compatible API. You can connect it to 75+ LLM providers or run models locally for full privacy.

Can OpenCode automate Git commits?

Yes. OpenCode can read your codebase, make changes, and even commit them to Git automatically. You can configure it to require your approval before committing.