Codex Desktop + DroidProxy Model Selector: A Shareable Guide

Help me configure Codex Desktop on this Mac so I can keep the standard OpenAI models and also select models routed through DroidProxy.

Work through the setup end to end. Inspect my existing Codex, DroidProxy, shim, and model-catalogue configuration before changing anything. Reuse what is already working and ask me only for values you cannot discover locally, such as the DroidProxy model mappings or a non-default port. Never print or expose credentials, tokens, cookies, auth files, private prompts, or sensitive logs.

The target setup is:
- Codex Desktop talks to one local OpenAI-compatible Responses API shim, bound to 127.0.0.1 (prefer http://127.0.0.1:8765/v1 unless my setup already uses another port).
- The shim routes standard OpenAI models normally and sends clearly named custom model IDs to DroidProxy.
- Codex uses a combined local model catalogue that retains the standard OpenAI entries and adds visible DroidProxy entries with unique IDs.
- ~/.codex/config.toml uses a custom provider with wire_api = "responses" and an absolute model_catalog_json path.

First verify the backend with codex debug models. If the DroidProxy entries are missing there, fix the catalogue, shim, or routing layer before touching Codex Desktop. If the backend lists the custom models but the Desktop selector still hides them, check whether the current release or openai/codex#19694 has fixed the issue. Only if the workaround is still required, use a version-aware macOS patch that:
- checks /Applications/ChatGPT.app/Contents/Resources/app.asar;
- requires exactly one use_hidden_models marker and no use_hidden_modelZ marker;
- creates a version-specific backup without overwriting an existing backup;
- changes only the same-length marker use_hidden_models to use_hidden_modelZ;
- restores the backup automatically if verification fails;
- ad-hoc signs the app and verifies the signature;
- stops without forcing anything if the marker counts or expected byte differ.

Have me save my work and quit Codex Desktop before patching. Keep every proxy service on localhost unless I explicitly request and secure remote access. Afterward, verify the listening services, backend model list, patch marker, app signature, selector entries, and one harmless request through a DroidProxy model.

Show me each proposed change before making it, explain anything you cannot verify, and finish with the exact verification and rollback commands. Never reuse an app.asar backup from a different Codex Desktop version and never package or distribute the patched app, app.asar, or its backup.

Codex Desktop
  -> local Codex shim on 127.0.0.1
      -> standard OpenAI models
      -> DroidProxy models

model_provider = "codex_shim"
model_catalog_json = "/Users/YOUR_USERNAME/.codex/combined-models.json"

[model_providers.codex_shim]
name = "OpenAI + DroidProxy"
base_url = "http://127.0.0.1:8765/v1"
wire_api = "responses"

droidproxy-grok-example
droidproxy-claude-example
droidproxy-gpt-example

codex debug models | jq -r '.models[] | [.slug, .visibility] | @tsv'

use_hidden_models
use_hidden_modelZ

#!/bin/zsh
set -euo pipefail

app_path="/Applications/ChatGPT.app"
info_path="$app_path/Contents/Info.plist"
asar_path="$app_path/Contents/Resources/app.asar"
backup_dir="$HOME/.codex/backups"

if [[ ! -f "$info_path" || ! -f "$asar_path" ]]; then
  print -u2 "ChatGPT/Codex Desktop application bundle was not found."
  exit 1
fi

app_version=$(/usr/libexec/PlistBuddy -c 'Print :CFBundleShortVersionString' "$info_path")
backup_path="$backup_dir/ChatGPT-app.asar-$app_version-original"

count_marker() {
  { grep -abo "$1" "$asar_path" || true; } | wc -l | tr -d ' '
}

original_count=$(count_marker 'use_hidden_models')
patched_count=$(count_marker 'use_hidden_modelZ')

if [[ "$original_count" == "0" && "$patched_count" == "1" ]]; then
  print "Already patched for ChatGPT/Codex Desktop $app_version"
  exit 0
fi

if [[ "$original_count" != "1" || "$patched_count" != "0" ]]; then
  print -u2 "Unexpected marker counts. The application layout may have changed."
  print -u2 "Original marker: $original_count; patched marker: $patched_count"
  exit 1
fi

offset=$(grep -abo 'use_hidden_models' "$asar_path" | cut -d: -f1)
target_offset=$((offset + 16))
current_byte=$(dd if="$asar_path" bs=1 skip="$target_offset" count=1 2>/dev/null)

if [[ "$current_byte" != "s" ]]; then
  print -u2 "Expected the final marker byte to be s; found $current_byte"
  exit 1
fi

mkdir -p "$backup_dir"

if [[ -e "$backup_path" ]]; then
  print -u2 "Refusing to overwrite existing backup: $backup_path"
  exit 1
fi

cp -p "$asar_path" "$backup_path"
printf 'Z' | dd of="$asar_path" bs=1 seek="$target_offset" count=1 conv=notrunc 2>/dev/null

if [[ "$(count_marker 'use_hidden_modelZ')" != "1" || "$(count_marker 'use_hidden_models')" != "0" ]]; then
  cp -p "$backup_path" "$asar_path"
  print -u2 "Patch verification failed. The original app.asar was restored."
  exit 1
fi

codesign --force --deep --sign - "$app_path"
codesign --verify --deep --strict "$app_path"

print "Patched Codex Desktop version: $app_version"
print "Backup: $backup_path"
print "Patched SHA-256: $(shasum -a 256 "$asar_path" | cut -d' ' -f1)"

chmod 700 /ABSOLUTE/PATH/TO/patch-codex-model-picker.sh

lsof -nP -iTCP:8765 -sTCP:LISTEN
lsof -nP -iTCP:8317 -sTCP:LISTEN

codex debug models | jq -r '.models[] | [.slug, .visibility] | @tsv'

grep -abo 'use_hidden_modelZ' /Applications/ChatGPT.app/Contents/Resources/app.asar
grep -abo 'use_hidden_models' /Applications/ChatGPT.app/Contents/Resources/app.asar

codesign --verify --deep --strict /Applications/ChatGPT.app

/usr/libexec/PlistBuddy -c 'Print :CFBundleShortVersionString' /Applications/ChatGPT.app/Contents/Info.plist

cp -p "$HOME/.codex/backups/ChatGPT-app.asar-VERSION-original" \
  /Applications/ChatGPT.app/Contents/Resources/app.asar

codesign --force --deep --sign - /Applications/ChatGPT.app
codesign --verify --deep --strict /Applications/ChatGPT.app