"How I Made Claude Code, Codex, and Gemini CLI Share One Local API"

I got tired of debugging my AI tooling by reading HTTP traces instead of writing code. Claude Code wanted Anthropic Messages. Codex CLI wanted OpenAI Responses, and sometimes its own internal /backend-api/codex/responses path. Gemini CLI wanted Google's v1beta/models/* endpoints. Every tool acted like its protocol was the normal one. The annoying part was not auth. It was compatibility. If I wanted one local gateway for all three tools, I needed to solve three problems at once: different request