OpenCode: Best Open Source Claude Code Alternative
Best for: developers who want a terminal-native AI coding agent that works across any editor and any model provider.
OpenCode is the most-starred open source AI coding tool I found: 162k+ GitHub stars and counting. The SST team built it as the open source answer to Claude Code: a terminal-native agent with a full TUI, a desktop app, and IDE extensions. Where Claude Code locks you to Anthropic, OpenCode works with 75+ providers through Models.dev, including Claude, OpenAI, Gemini, and local models. Same workflow, full model choice.
The repository was active during this review window, and the client/server architecture means you can run the server on a remote machine and drive it from your terminal, desktop, or mobile app.
Key Features
- 75+ LLM providers: Claude, OpenAI, Gemini, Ollama, and other providers through Models.dev (not locked to any single vendor)
- Two built-in agents: “build” (full access to read, write, and execute) and “plan” (read-only analysis and exploration), switchable with Tab
- LSP support: Automatically loads the correct language server for the language in your working directory
- Multi-session: Run multiple agents on the same project in parallel
- Share links: Share a link to any session for debugging or review
- Cross-platform: Terminal TUI, desktop app (macOS, Windows, Linux beta), and IDE extensions
- Privacy-first: No code or context data stored server-side
- GitHub Copilot and ChatGPT login: Sign in with existing GitHub Copilot or ChatGPT Plus subscriptions to use those model credits
Pros
- 162k+ GitHub stars, the largest open source AI coding community I found
- Provider-agnostic: swap models without changing your workflow
- Terminal-native design serves developers who live in the command line
- Privacy guarantee: zero data stored, runs fully local with Ollama
Cons
- Terminal UI has a steeper learning curve than GUI-native tools
- No deep integration with a specific editor (editor-agnostic means no editor-native features)
- Optional “Zen” managed model tier is paid; the free path requires your own API keys
License and Hosting
MIT licensed. Runs entirely on your machine. No data leaves your system unless you send it to an AI provider. Install via curl -fsSL https://opencode.ai/install | bash, npm, Homebrew, or Scoop.
Best For
Developers who want a Claude Code-style terminal agent without the Anthropic lock-in. Strong for anyone switching editors frequently, working in multiple codebases, or running agents on remote machines.
Skip OpenCode if you want deep VS Code integration (Cline gives you Plan/Act oversight inside VS Code) or a fully autonomous agent that returns a complete PR (OpenHands handles that better).
List of free AI models supported
| Model ID | Model Name | Context | Output |
|---|---|---|---|
| big-pickle | Big Pickle | 200K | 32K |
| mimo-v2.5-free | MiMo-V2.5 Free | 200K | 32K |
| laguna-s-2.1-free | Laguna S 2.1 Free | 256K | 32K |
| ling-3.0-flash-free | Ling-3.0-flash Free | 262K | 32K |
| north-mini-code-free | North Mini Code Free | 256K | 64K |
| nemotron-3-ultra-free | Nemotron 3 Ultra Free | 1M | 128K |
| deepseek-v4-flash-free | DeepSeek V4 Flash Free | 200K | 128K |
Benchmark
| Model | Size (total params.) | SWE-bench Verified | SWE-bench Multilingual | SWE-Bench Pro (Public Dataset) | Terminal-Bench 2.0 |
|---|---|---|---|---|---|
| Laguna XS 2.1 | 33B | 70.9% | 63.1% | 47.6% | 37.5% |
| Laguna XS.2 | 33B | 69.9% | 57.7% | 46.3% | 35.7% |
| Qwen3.6-35B-A3B | 35B | 73.4% | 67.2% | 49.5% | 51.5% |
| North Mini Code | 30B | 67.6% | - | 40.2% | 36.0% |
| MAI-Code-1-Flash | 137B | 71.6% | 65.5% | 51.2% | 54.8% |
| gpt-oss-120B | 120B | - | - | 16.2% | 18.7% |
| Claude Haiku 4.5 | - | 73.3% | - | 39.5% | 29.8% |
| GPT-5.4 Nano | - | - | - | 52.4% | 46.3% |