Codex can’t properly fetch dependencies for Elixir mix projects (like Phoenix). Doing a simple mix deps.get is causing all kinds of issues with the proxy that the Codex Cloud VM is using. Elixir is a popular programming language and currently to get it working with Codex, we need to use alternative…

Alright, I put my final solution into a small Golang proxy. With this set I can now natively resolve hex.pm packages in Codex Maintenance Script: mise use -g go:github.com/dvcrn/hexpm-envoy-proxy@latest if ! pgrep -f hexpm-envoy-proxy > /dev/null 2>&1; then nohup mise x -- hexpm-envoy-proxy > /t…

2026 and Codex is still unable to properly install deps from hex due to proxy issues. I can get sometimes get around it with a bunch of hacky reverse-proxy stuff but it’s still very fragile. I’d much rather have a single setup script that just does a mix deps.get instead of trying to funnel everyth…

I defered to using github instead. e.g. {:postgrex, github: “elixir-ecto/postgrex”, tag: “v0.17.4”}, It works great so far.

How are you installing hex and friends?

[image] LazyCloud: I wasn’t able to find where to report feedback or bugs Issues for Codex can be reported at https://github.com/openai/codex/issues [image] openai/codex Lightweight coding agent that runs in your terminal - openai/codex Before postin…

Alright, I’ve now tried to update all deps to use github, and install hex + rebar3 from github It works for my own deps, but all transitive deps are still failing. So if one dep is having a dep on something else, it still tries to pull this from hex, and the Codex Cloud MITM proxy is failing

@EricGT this issue is specific to the Codex Cloud environment. The CLI works fine so it doesn’t really fit into that GitHub repository

Thanks. I don’t use the cloud environment. OpenAI staff don’t visit this forum regularly, but they do monitor GitHub issues. If this were my issue, I would still file it as a Codex issue—there’s a chance someone from OpenAI would respond there. That’s the best guidance I can offer. I hope you’r…

Created an on GitHub #10502 (This forum doesn’t allow me to include links) Codex Cloud can't fetch deps from hex.pm (Elixir package manager) opened 11:34AM - 03 Feb 26 UTC (UTC) [image] dvcrn …

Free moderator service, added link to post.

I think I finally figured out what’s causing codex to not work with hex.pm The issue is with httpc that it uses to connect to hex. 2 issues here: Missing certificates, fix with HEX_CACERTS_PATH=/usr/local/share/ca-certificates/envoy-mitmproxy-ca-cert.crt httpc sends empty headers (like Te: ) whic…

Codex Cloud has severe issues with hex.pm (Elixir package manager)

Codex

EricGT February 3, 2026, 10:06am 5

Issues for Codex can be reported at

https://github.com/openai/codex/issues

Before posting always check if this has been reported and also check for closed issues as they may have a solution or workaround posted with them.

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Codex Cloud has severe issues with hex.pm (Elixir package manager)

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