Using Claude Code with Gemini/OpenAI models

I’ve been wanting to try Anthropic’s Claude Code for a while now, and tried this out today. While exploring options, I came across Claude Code Proxy which is a neat way to use Gemini or OpenAI models with Claude code, instead of just relying on the (expensive) Anthropic models. It works by proxying prompts from claude models to Gemini/OpenAI models that you can configure. To save cost, it uses a BIG_MODEL for complex queries, and SMALL_MODEL for simpler queries. Sonnet and Haiku are the default models for Anthropic, but I tried with gemini-2.5-pro-preview-03-25 for the BIG_MODEL, and gemini-2.0-flash for the SMALL_MODEL. Use the Gemini models page for up-to-date names of these models.