The best open source alternative to Codex is opencode. If that doesn't suit you, our users have ranked more than 50 alternatives to Codex and many of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Codex are Void, Mellum, TabbyML and Emdash.
Terminal-based AI coding assistant featuring a themed native UI, automatic LSP integration, multi-agent sessions, 75+ supported LLMs, local and cloud model options, shareable debugging links, open source licensing, and session sharing for collaborative coding workflows.
The open source AI code editor. Write code with the best AI tools, use any model, and retain full control over your data.
Mellum-4b-base is JetBrains' first open-source large language model (LLM) optimized for code-related tasks.
Tabby is an open-source, self-hosted AI coding assistant. With Tabby, every team can set up its own LLM-powered code completion server with ease.
Emdash is a provider-agnostic desktop app that lets you run multiple coding agents in parallel, each isolated in its own git worktree, either locally or over SSH on a remote machine. We call it an Agentic Development Environment (ADE).
Autonomous coding agent right in your IDE, capable of creating/editing files, executing commands, using the browser, and more with your permission every step of the way.
Continue is the leading open-source AI code assistant. You can connect any models and any context to build custom autocomplete and chat experiences inside VS Code and JetBrains.
A multi-platform, AI-augmented coding companion ensuring secure development with unit test creation.
Visual AI programming platform with a graphical interface for creating, editing, and debugging LLM agent workflows, supporting real-time collaboration, YAML-based version control, open-source TypeScript library integration, and scalable deployment in production environments.
CodeGeeX is an AI-based coding assistant, which can suggest code in the current or following lines. It is powered by a large-scale multilingual code generation model with 13 billion parameters, pretrained on a large code corpus of more than 20 programming languages.
The most no-nonsense locally hosted (or API hosted) AI code completion plugin for Visual Studio Code, like GitHub Copilot but 100% free and 100% private.
Open source AI coding assistant for planning, building, and fixing code. We frequently merge features from open-source projects like Roo Code and Cline, while building our own vision.
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