Claude Code with Local LLMs and ANTHROPIC_BASE_URL: Ollama, LM Studio, llama.cpp, vLLM

Native Anthropic endpoints, tool-call compatibility, and context-window sizing for local Claude Code. Last tested: April 2026. See Changelog at the bottom. TL;DR cheat sheet Goal Use MacBook Air Gemma 4 26B-A4B Q4, 32K context , LM Studio or Ollama MacBook Pro Gemma 4 26B-A4B Q4 / UD-Q4, 64K context , llama.cpp or LM Studio Claude Code minimum 32K context (anything below is a chat demo) Best local backend LM Studio or Ollama first; llama.cpp for advanced; vLLM for servers Avoid 8K / 16K context,