Known limits
Every gateway has a list like this. Most of them do not publish it.
Codex CLI
Codex speaks OpenAI’s Responses API. MagmaRouter serves chat completions and Anthropic messages, and no environment variable bridges the two. A Responses dialect is the fix and it is on the list. Any guide claiming Codex works against a chat-completions gateway today is describing a different tool.
Cursor
Partial. It accepts a custom OpenAI base URL, but the override is documented only in staff forum posts and some paths still check against OpenAI directly.
Server-side tools
Anthropic’s hosted tools, web search among them, have no chat-completions equivalent upstream, so they cannot be offered here regardless of model.
Tool calling on uncensored models
One uncensored model supports tools today. See tool calling before designing an agent around the uncensored catalogue.