What is open and what is not
anthropics/claude-codeon GitHub is the public issue tracker and docs, not the source.anthropics/claude-code-action(GitHub Action) and the Claude Agent SDKs are open source.anthropics/skillsis open — the document skills and the skill-creator.- The plugin and skill formats are open specifications; anyone can publish a marketplace.
The source-map exposure
In 2026 an npm release shipped with source maps, exposing readable internals of the CLI. It circulated widely and was analysed in detail — our write-up is linked below. It did not make Claude Code open source: the licence is unchanged, and the exposed code cannot be legally redistributed or built upon. What it did do is confirm the architecture people had inferred: an agent loop over a tool set, a permission system, and a lot of prompt engineering.
Open-source alternatives that use the same API
- OpenCode — terminal agent, multi-provider, closest in feel.
- Aider — the original pair-programming CLI, git-native, very token-efficient.
- Cline / Roo Code / Kilo Code — VS Code agents with a similar autonomous edit loop.
- Goose — Block's extensible agent with MCP at its core.
- All of them accept an Anthropic-compatible base URL, so a gateway key works unchanged; each has a setup guide in the Learn section.
Does it matter?
For most users, no: the tool's value is the model behind it, and that is available through the API to any client. Where it matters is auditability and lock-in, and the open agents above are the answer to both.
Frequently asked questions
Can I read the Claude Code source code?
Not legitimately as a licensed source release. The npm package is minified; the 2026 source-map exposure was an accident, not a publication.
Is there an open-source version of Claude Code?
No official one. OpenCode, Aider, Cline and Goose are open agents that cover the same ground and work with the same API.
Is the Claude Code SDK open source?
Yes — the Claude Agent SDK for Python and TypeScript is published openly, as is the GitHub Action.
Run Claude Code on the gateway
Same models, two environment variables, credits at 7.69× face value — or a flat-rate unlimited plan.
Get an API key See unlimited plansAI Prime Tech is an independent API gateway and is not affiliated with, endorsed by, or sponsored by Anthropic. “Claude” and “Claude Code” are trademarks of Anthropic. Claude Code features described here follow Anthropic’s public documentation at the time of writing and change frequently; prices and model lists on this page are read from this gateway’s live settings.