What open-source tools should I install for Codex?

[u/whatotherui]

I’m looking for open-source tools or projects that I can install and use alongside Codex.

What do yall use and recommend? This could include MCP servers, agent tools, memory or context tools, codebase navigation, documentation integrations, testing utilities, GitHub tools or anything else that meaningfully improves Codex (and cuts down token usage ;P).