This project addresses the need to use Anthropic's Claude Science platform with custom, third-party AI models without requiring a paid Claude subscription. It targets users who want to integrate their own API keys from providers like DeepSeek, Qwen, GLM, Kimi, and others into the Claude Science research environment, offering a flexible and cost-effective alternative.

How It Works

CSSwitch operates by creating a local proxy and managing an isolated environment for Claude Science. It generates a temporary, local login state for Science, circumventing the need for actual Anthropic credentials. Science is then configured to route inference requests through a local proxy. This proxy strips Anthropic authentication, injects user-provided API keys, and performs necessary protocol conversions (e.g., for OpenAI-compatible endpoints) before forwarding requests to the selected third-party model.

Quick Start & Requirements

• Installation: Download the latest CSSwitch_*.dmg release and drag it to the Applications folder. Requires macOS on Apple Silicon (arm64).
• Prerequisites: Claude Science must be installed, and the system needs Python 3. Virtual login is implemented in Rust, eliminating the need for Node.js.
• Setup: Open CSSwitch, navigate to "Third-party Model", click "+ New", select a provider, paste your API Key, and set it as current. CSSwitch validates the key and then initiates the proxy, local login, isolated environment, and opens Science in the browser via a "one-click start" process.
• Docs: Detailed development and build steps are available in docs/DEVELOPMENT.md and desktop/README.md.

Highlighted Details

• Broad Provider Support: Integrates with DeepSeek (native Anthropic endpoint), Qwen, GLM, Kimi, MiniMax, MiMo, SiliconFlow, OpenRouter, and custom OpenAI/Anthropic compatible endpoints.
• Seamless Integration: Automates proxy setup, local login generation, and Science startup. It preserves the actual model names within Science's UI, avoiding generic labels.
• Enhanced Security: API keys are stored locally with strict 0600 permissions in ~/.csswitch and are masked in the UI. The proxy only accepts local connections and strips original credentials.
• Key Validation: API keys are validated upon configuration to ensure validity before activation.
• Flexible Switching: Provides an option to easily switch back to official Claude services without CSSwitch interference.

Maintenance & Community

• Roadmap: Future plans include broader API support (e.g., Ollama), improved direct connections for native providers, a Rust rewrite of the proxy, Intel (x86_64) builds, and official code signing/notarization.
• Feedback: Users can report bugs or suggest features via GitHub Issues. Local logs are accessible at ~/.csswitch/logs/.

Licensing & Compatibility

• License: MIT.
• Usage: Intended strictly for personal learning and research. It does not utilize Anthropic's inference services; inference costs are borne by the user with their chosen third-party provider. The local login state is isolated and does not contain real Anthropic credentials.
• Restrictions: Anthropic-hosted MCP services (e.g., pubmed, clinical-trials) are unavailable when using local login. Analysis of Science's token encryption and local login generation may have implications under DMCA §1201, requiring professional legal assessment. The project has no affiliation with Anthropic.

Limitations & Caveats

• Platform Support: Currently limited to macOS on Apple Silicon (arm64); Intel (x86_64) support is planned but not yet available.
• Service Availability: Remote Anthropic MCP services hosted on *.mcp.claude.com are inaccessible.
• Legal Considerations: The method of generating local login states may raise legal questions under DMCA §1201, necessitating user discretion and professional legal advice.