openclaude
Use Claude Code with any LLM — not just Claude.
OpenClaude is a fork of the Claude Code source leak (exposed via npm source maps on March 31, 2026). We added an OpenAI-compatible provider shim so you can plug in GPT-4o, DeepSeek, Gemini, Llama, Mistral, or any model that speaks the OpenAI chat completions API. It now also supports the ChatGPT Codex backend for codexplan and codexspark, and local inference via Atomic Chat on Apple Silicon.
All of Claude Code's tools work — bash, file read/write/edit, grep, glob, agents, tasks, MCP — just powered by whatever model you choose.
Start Here
If you are new to terminals or just want the easiest path, start with the beginner guides:
If you want source builds, Bun workflows, profile launchers, or full provider examples, use:
Beginner Install
For most users, install the npm package:
npm install -g @gitlawb/openclaude
The package name is @gitlawb/openclaude, but the command you run is:
openclaude
If you install via npm and later see ripgrep not found, install ripgrep system-wide and confirm rg --version works in the same terminal before starting OpenClaude.
Fastest Setup
Windows PowerShell
npm install -g @gitlawb/openclaude
$env:CLAUDE_CODE_USE_OPENAI="1"
$env:OPENAI_API_KEY="sk-your-key-here"
$env:OPENAI_MODEL="gpt-4o"
openclaude
macOS / Linux
npm install -g @gitlawb/openclaude
export CLAUDE_CODE_USE_OPENAI=1
export OPENAI_API_KEY=sk-your-key-here
export OPENAI_MODEL=gpt-4o
openclaude
That is enough to start with OpenAI.
Choose Your Guide
Beginner
- Want the easiest setup with copy-paste steps: Non-Technical Setup
- On Windows: Windows Quick Start
- On macOS or Linux: macOS / Linux Quick Start
Advanced
- Want source builds, Bun, local profiles, runtime checks, or more provider choices: Advanced Setup
Common Beginner Choices
OpenAI
Best default if you already have an OpenAI API key.
Ollama
Best if you want to run models locally on your own machine.
Codex
Best if you already use the Codex CLI or ChatGPT Codex backend.
Atomic Chat
Best if you want local inference on Apple Silicon with Atomic Chat. See Advanced Setup.
What Works
- All tools: Bash, FileRead, FileWrite, FileEdit, Glob, Grep, WebFetch, WebSearch, Agent, MCP, LSP, NotebookEdit, Tasks
- Streaming: Real-time token streaming
- Tool calling: Multi-step tool chains (the model calls tools, gets results, continues)
- Images: Base64 and URL images passed to vision models
- Slash commands: /commit, /review, /compact, /diff, /doctor, etc.
- Sub-agents: AgentTool spawns sub-agents using the same provider
- Memory: Persistent memory system
What's Different
- No thinking mode: Anthropic's extended thinking is disabled (OpenAI models use different reasoning)
- No prompt caching: Anthropic-specific cache headers are skipped
- No beta features: Anthropic-specific beta headers are ignored
- Token limits: Defaults to 32K max output — some models may cap lower, which is handled gracefully
How It Works
The shim (src/services/api/openaiShim.ts) sits between Claude Code and the LLM API:
Claude Code Tool System
|
v
Anthropic SDK interface (duck-typed)
|
v
openaiShim.ts <-- translates formats
|
v
OpenAI Chat Completions API
|
v
Any compatible model
It translates:
- Anthropic message blocks → OpenAI messages
- Anthropic tool_use/tool_result → OpenAI function calls
- OpenAI SSE streaming → Anthropic stream events
- Anthropic system prompt arrays → OpenAI system messages
The rest of Claude Code doesn't know it's talking to a different model.
Model Quality Notes
Not all models are equal at agentic tool use. Here's a rough guide:
| Model | Tool Calling | Code Quality | Speed |
|---|---|---|---|
| GPT-4o | Excellent | Excellent | Fast |
| DeepSeek-V3 | Great | Great | Fast |
| Gemini 2.0 Flash | Great | Good | Very Fast |
| Llama 3.3 70B | Good | Good | Medium |
| Mistral Large | Good | Good | Fast |
| GPT-4o-mini | Good | Good | Very Fast |
| Qwen 2.5 72B | Good | Good | Medium |
| Smaller models (<7B) | Limited | Limited | Very Fast |
For best results, use models with strong function/tool calling support.
Files Changed from Original
src/services/api/openaiShim.ts — NEW: OpenAI-compatible API shim (724 lines)
src/services/api/client.ts — Routes to shim when CLAUDE_CODE_USE_OPENAI=1
src/utils/model/providers.ts — Added 'openai' provider type
src/utils/model/configs.ts — Added openai model mappings
src/utils/model/model.ts — Respects OPENAI_MODEL for defaults
src/utils/auth.ts — Recognizes OpenAI as valid 3P provider
6 files changed. 786 lines added. Zero dependencies added.
Origin
This is a fork of instructkr/claude-code, which mirrored the Claude Code source snapshot that became publicly accessible through an npm source map exposure on March 31, 2026.
The original Claude Code source is the property of Anthropic. This repository is not affiliated with or endorsed by Anthropic.
License
This repository is provided for educational and research purposes. The original source code is subject to Anthropic's terms. The OpenAI shim additions are public domain.
