Open-source coding agents let you read exactly what runs on your machine, patch it, self-host it and avoid being locked to one vendor’s models. In 2026 the list grew: Warp open-sourced its terminal in April, and Goose moved under the Linux Foundation. Here’s where each one stands.
The list
| Agent | Licence | Kind | How you pay for models |
|---|---|---|---|
| Codex CLI | Apache 2.0 | Terminal agent | ChatGPT plan or OpenAI API key |
| Gemini CLI | Apache 2.0 | Terminal agent | Code Assist licence or paid Gemini API key |
| Cline | Apache 2.0 | VS Code, CLI, desktop | Your own keys, or ClinePass ($9.99) |
| OpenCode | MIT | Terminal, desktop, mobile | Your own keys, ChatGPT/Copilot sign-in, or OpenCode Go ($10) |
| Goose | Apache 2.0 | CLI, desktop, ACP server | Your own provider or subscription |
| Warp | AGPL-3.0 (UI crates MIT) | Terminal with agents | Warp usage at API rates, your own keys, or ChatGPT |
| Zed | Open source | Editor with agent panel | Your own keys (free) or Zed Pro ($10) |
Picking one
If you live in the terminal and use ChatGPT: Codex CLI is the official, open-source agent, and works with your plan or an API key.
If you want maximum model choice: OpenCode supports more than 200 providers and local models. Cline is the strongest choice inside VS Code, with local models through Ollama or LM Studio.
If you want a foundation-governed project: Goose is now under the Agentic AI Foundation at the Linux Foundation, with no paid tier at all.
If you want an editor rather than an agent: Zed is a fast native editor whose agent panel can also host Claude Agent and Codex CLI through the Agent Client Protocol.
If you’re on Gemini CLI: it’s still open source but now limited to paid Code Assist and API users. See Gemini CLI is winding down.
Recent changes worth knowing
- Cline fixed a high-severity WebSocket hijack in its dashboard command in June (CVE-2026-59723) and is rolling out a rebuilt SDK-based extension in stages.
- Gemini CLI shipped several security hardening releases in September, including keeping credentials out of sandboxes.
- OpenCode 2.3 made subagents run in the background by default.
- Zed now sandboxes its agent’s terminal and fetch tools by default.
Open source isn’t free inference
Every agent here is free to run, but the models aren’t. You’ll still pay a model provider, a subscription, or run open-weight models locally. Our Models section lists API prices for the models these agents use, and AI coding tools that work with your own API key covers the billing side.
Frequently asked questions
Is Codex open source?
The Codex CLI is open source under the Apache 2.0 licence in the openai/codex repository. The Codex cloud service and desktop app are part of ChatGPT and aren't.
Which open-source coding agent works with the most models?
OpenCode (MIT) supports 200+ providers through Models.dev, including local models. Cline (Apache 2.0) and Goose (Apache 2.0) also work with most major providers and local models through Ollama or LM Studio.
Is Claude Code open source?
Anthropic publishes a public changelog for Claude Code on GitHub, but we haven't confirmed an open-source licence for the agent itself, so it isn't on this list.
Is Antigravity CLI open source?
No. Google's antigravity-cli repository holds the README, changelog and issue tracker only, without source code or a licence.