Upstream README

Use this fork instead of hex/hexpm to have mix deps.get work in OpenAI Codex Cloud.

Add this to your setup script:

curl -o openai_codex_setup.sh "https://raw.githubusercontent.com/650health/hex/refs/heads/latest/openai_codex_setup.sh"
chmod +x openai_codex_setup.sh
./openai_codex_setup.sh

mix deps.get

This will:

• Download this patched version of hex
• Download rebar3, needed to download erlang packages

When running code in Codex, one must send requests via the proxy server.

Running mix deps.get fails in the base environment of the container. When run for the first time, mix deps.get uses Erlang/OTP httpc module to make get requests, which has an incompatibility with the Codex proxy server. By default, it sends an empty te header if the caller doesn't supply one.

The fundamental issue is that the Codex proxy returns a 503 if te header is set to "".

This patch changes the header to something semantically equivalent (deflate;q=0), which is equivalent to sending nothing.

This issue in httpc causes mix and hex to fail in multiple ways:

• When running mix for the first time, if it detects Hex dependencies, it will first attempt to download hex package manager (using a httpc get request). This will fail due to the httpc issue above.
• It will also attempt to download rebar3, also using a httpc get requests, also failing.
• Hex also downloads packages with a httpc get request, which would also fail without this patch.

The first two issues are in mix, which openai_codex_setup.sh is able to get around by downloading this patched version of hex using git and rebar3 using curl and installing manually. The latter issue is in hex, which the patch in this repo corrects. This is not a patch for mix, so any other HTTP GET requests made by mix may still fail since it also uses httpc get requests.

In the meantime, I have opened an issue in Erlang/OTP to fix the root cause in httpc: erlang/otp#10065.