codex-model-filter-patch.sh

codex-model-filter-patch.sh

#!/bin/bash
# ============================================================================
# Codex Desktop (ChatGPT.app) model-picker patch for macOS
# Strategy: build in /tmp, then swap back into /Applications
#
# Problem
#   After switching Codex to a third-party provider (DeepSeek, Kimi, GLM, ...),
#   the model picker only shows "Custom" instead of the real model name.
#
# Cause
#   The bundled UI filters models against a remote OpenAI whitelist
#   (useHiddenModels / available_models). Third-party slugs are dropped, so the
#   composer falls back to the "Custom" label.
#
# What this script does
#   Disables that whitelist filter inside the packaged webview JS, then repacks
#   app.asar, updates ElectronAsarIntegrity, and ad-hoc re-signs the app.
#
# Why build under /tmp
#   /Applications/ChatGPT.app is Developer ID signed and protected by macOS
#   App Management (TCC). In-place asar edits / codesign often fail with
#   "Operation not permitted" (commonly on CodexDockTilePlugin.plugin).
#   sudo does NOT bypass TCC.
#
#   Flow:
#     1) Copy the whole app to /tmp (reads are allowed)
#     2) Patch asar + recompute integrity hash + ad-hoc codesign under /tmp
#     3) Swap the finished app back into /Applications
#
#   Step 3 still needs one of:
#     (a) Your terminal app is allowed under
#         System Settings → Privacy & Security → App Management
#     (b) Manual Finder replace if the automated swap fails (no extra grant)
#
# Requirements
#   - macOS with Codex Desktop at /Applications/ChatGPT.app
#   - Node.js (npx) for @electron/asar
#   - codesign, PlistBuddy (ship with macOS)
#
# Usage
#   bash codex-model-filter-patch.sh          # apply patch
#   bash codex-model-filter-patch.sh restore  # restore latest backup
#
# Risks
#   - Modifies the local Codex / ChatGPT.app bundle
#   - App updates overwrite the patch; re-run after each update
#   - Ad-hoc signing may require re-approving Accessibility / Screen Recording
#   - Optional: everything still works without this; only the label stays Custom
#
# License: use at your own risk. Not affiliated with OpenAI.
# ============================================================================
set -euo pipefail

APP="/Applications/ChatGPT.app"
STAGE="/tmp/ChatGPT.app"   # patched + signed build output
WORK="/tmp/codex-patch-$$"
TS="$(date +%Y%m%d-%H%M%S)"
BAK_DIR="${CODEX_PATCH_BACKUP_DIR:-$HOME/codex-patch-backups}"

log() { printf '\033[1;36m>>> %s\033[0m\n' "$*"; }
err() { printf '\033[1;31m!!! %s\033[0m\n' "$*" >&2; }

# npx cache path for @electron/asar (integrity hash)
NPX_ASAR="$(find "$HOME/.npm/_npx" -type d -path '*/node_modules/@electron/asar' 2>/dev/null \
  | head -1 | xargs -I{} dirname {} | xargs -I{} dirname {} 2>/dev/null || true)"

# ---------------------------------------------------------------------------
# restore mode
# ---------------------------------------------------------------------------
if [[ "${1:-}" == "restore" ]]; then
  LAST_ASAR="$(ls -t "$BAK_DIR"/app.asar.bak.* 2>/dev/null | head -1 || true)"
  LAST_PLIST="$(ls -t "$BAK_DIR"/Info.plist.bak.* 2>/dev/null | head -1 || true)"
  [[ -z "$LAST_ASAR" ]] && { err "No backup found under $BAK_DIR"; exit 1; }
  log "Quitting ChatGPT..."
  osascript -e 'quit app "ChatGPT"' 2>/dev/null || true; sleep 2
  pkill -f "ChatGPT.app/Contents/MacOS/ChatGPT" 2>/dev/null || true; sleep 2
  log "Restoring app.asar <- $LAST_ASAR"
  cp "$LAST_ASAR" "$APP/Contents/Resources/app.asar" || {
    err "Write failed (App Management permission?). Use Finder or grant access, then retry."
    exit 1
  }
  [[ -n "$LAST_PLIST" ]] && cp "$LAST_PLIST" "$APP/Contents/Info.plist"
  log "Re-signing..."
  xattr -cr "$APP" 2>/dev/null || true
  codesign --force --deep --sign - --timestamp=none "$APP"
  codesign -v "$APP" && log "Restore complete"
  exit 0
fi

# ---------------------------------------------------------------------------
# 0. Preconditions
# ---------------------------------------------------------------------------
[[ -d "$APP" ]] || { err "App not found: $APP"; exit 1; }
command -v npx >/dev/null || { err "npx (Node.js) is required"; exit 1; }
if [[ -z "$NPX_ASAR" ]]; then
  log "Warming up @electron/asar..."
  npx -y @electron/asar --version >/dev/null 2>&1
  NPX_ASAR="$(find "$HOME/.npm/_npx" -type d -path '*/node_modules/@electron/asar' 2>/dev/null \
    | head -1 | xargs -I{} dirname {} | xargs -I{} dirname {})"
fi

# ---------------------------------------------------------------------------
# 1. Quit ChatGPT / Codex
# ---------------------------------------------------------------------------
log "Step 1: quitting ChatGPT..."
osascript -e 'quit app "ChatGPT"' 2>/dev/null || true; sleep 2
pkill -f "ChatGPT.app/Contents/MacOS/ChatGPT" 2>/dev/null || true; sleep 2

# ---------------------------------------------------------------------------
# 2. Copy app to /tmp (read-only w.r.t. App Management)
# ---------------------------------------------------------------------------
log "Step 2: copying app to $STAGE ..."
rm -rf "$STAGE"
cp -R "$APP" "$STAGE"

log "  Backing up original asar/plist to $BAK_DIR ..."
mkdir -p "$BAK_DIR"
cp "$APP/Contents/Resources/app.asar" "$BAK_DIR/app.asar.bak.$TS"
cp "$APP/Contents/Info.plist"         "$BAK_DIR/Info.plist.bak.$TS"

RES="$STAGE/Contents/Resources"
ASAR="$RES/app.asar"
UNPACKED="$RES/app.asar.unpacked"
PLIST="$STAGE/Contents/Info.plist"

# ---------------------------------------------------------------------------
# 3. Extract asar under /tmp
# ---------------------------------------------------------------------------
log "Step 3: extracting app.asar ..."
rm -rf "$WORK"; mkdir -p "$WORK/extract"
npx -y @electron/asar extract "$ASAR" "$WORK/extract"

# ---------------------------------------------------------------------------
# 4. Locate and patch filter code (chunk hashes change every build)
#   Older builds:
#     l=o&&e!==`amazonBedrock`  ->  l=!1
#   Newer builds (app-initial):
#     B1 useHiddenModels:n.success?n.data:X.useHiddenModels -> useHiddenModels:!1
#     B2 i&&t!==`amazonBedrock`?n.has(r.model):!r.hidden     -> !r.hidden
#     B3 i.useHiddenModels&&r!==`amazonBedrock`?i.availableModels.has(e.model):!e.hidden
#        -> !e.hidden
# ---------------------------------------------------------------------------
log "Step 4: locating model filter code..."
ASSETS="$WORK/extract/webview/assets"
PATCHED=0

# --- Path A: older minified assignment ---
TARGET_OLD="$(grep -rl 'l=o&&e!==`amazonBedrock`' "$ASSETS/" 2>/dev/null | head -1 || true)"
if [[ -n "$TARGET_OLD" ]]; then
  log "  [old] target: ${TARGET_OLD#$WORK/extract/}"
  perl -pi -e 's/l=o&&e!==`amazonBedrock`/l=!1/' "$TARGET_OLD"
  grep -q 'l=o&&e!==`amazonBedrock`' "$TARGET_OLD" && { err "Old-pattern replace failed"; exit 1; }
  log "  [old] l=o&&e!==\`amazonBedrock\`  ->  l=!1"
  PATCHED=$((PATCHED + 1))
fi

# --- Path B: useHiddenModels / availableModels whitelist ---
TARGET_NEW=""
while IFS= read -r f; do
  if grep -q 'amazonBedrock' "$f" && grep -q 'availableModels' "$f"; then
    TARGET_NEW="$f"
    break
  fi
done < <(grep -rl 'useHiddenModels' "$ASSETS/" --include='*.js' 2>/dev/null || true)

if [[ -n "$TARGET_NEW" ]]; then
  log "  [new] target: ${TARGET_NEW#$WORK/extract/}"
  BEFORE_HASH="$(cksum "$TARGET_NEW" | awk '{print $1" "$2}')"
  NEW_HITS=0

  # B1: force useHiddenModels off
  # Note: Perl s/// interpolates; escape $ inside the character class as \$
  if grep -qE 'useHiddenModels:n\.success\?n\.data:[A-Za-z0-9_$]+\.useHiddenModels' "$TARGET_NEW"; then
    perl -pi -e 's/useHiddenModels:n\.success\?n\.data:[A-Za-z0-9_\$]+\.useHiddenModels/useHiddenModels:!1/g' "$TARGET_NEW"
    log "  [new] useHiddenModels forced to !1"
    NEW_HITS=$((NEW_HITS + 1)); PATCHED=$((PATCHED + 1))
  fi
  # B2: single-model visibility
  if grep -q 'i&&t!==`amazonBedrock`?n.has(r.model):!r.hidden' "$TARGET_NEW"; then
    perl -pi -e 's/i&&t!==`amazonBedrock`\?n\.has\(r\.model\):!r\.hidden/!r.hidden/g' "$TARGET_NEW"
    log "  [new] item filter -> !r.hidden"
    NEW_HITS=$((NEW_HITS + 1)); PATCHED=$((PATCHED + 1))
  fi
  # B3: list filter
  if grep -q 'i.useHiddenModels&&r!==`amazonBedrock`?i.availableModels.has(e.model):!e.hidden' "$TARGET_NEW"; then
    perl -pi -e 's/i\.useHiddenModels&&r!==`amazonBedrock`\?i\.availableModels\.has\(e\.model\):!e\.hidden/!e.hidden/g' "$TARGET_NEW"
    log "  [new] list filter -> !e.hidden"
    NEW_HITS=$((NEW_HITS + 1)); PATCHED=$((PATCHED + 1))
  fi

  AFTER_HASH="$(cksum "$TARGET_NEW" | awk '{print $1" "$2}')"
  if [[ "$NEW_HITS" -eq 0 || "$BEFORE_HASH" == "$AFTER_HASH" ]]; then
    err "Found a new-pattern target file but no replacements applied."
    err "Inspect useHiddenModels near amazonBedrock in the extracted assets."
    exit 1
  fi
fi

if [[ "$PATCHED" -eq 0 ]]; then
  err "Neither old nor new filter patterns were found."
  err "Codex may have changed minified code. Search for useHiddenModels / amazonBedrock."
  grep -rl 'useHiddenModels' "$ASSETS/" --include='*.js' 2>/dev/null | head || true
  exit 1
fi
log "  Applied $PATCHED replacement(s)"

# ---------------------------------------------------------------------------
# 5. Native modules that must stay unpacked
# ---------------------------------------------------------------------------
log "Step 5: computing unpack list for native modules..."
UNPACK_MODS="$(find "$UNPACKED/node_modules" -maxdepth 1 -mindepth 1 -type d 2>/dev/null \
  | sed 's|.*/||' | sort -u | paste -sd'|' -)"
if [[ -z "$UNPACK_MODS" ]]; then
  err "No modules found under app.asar.unpacked/node_modules; aborting to avoid a broken pack."
  exit 1
fi
log "  unpack modules: $UNPACK_MODS"

# ---------------------------------------------------------------------------
# 6. Repack (keep native modules unpacked)
# ---------------------------------------------------------------------------
log "Step 6: repacking asar..."
npx -y @electron/asar pack "$WORK/extract" "$WORK/app.asar.new" \
  --unpack-dir "node_modules/@($UNPACK_MODS)"

log "  Copying any missing unpacked files..."
( cd "$UNPACKED" && find . -type f ) | while read -r f; do
  if [[ ! -f "$WORK/app.asar.new.unpacked/$f" ]]; then
    mkdir -p "$WORK/app.asar.new.unpacked/$(dirname "$f")"
    cp "$UNPACKED/$f" "$WORK/app.asar.new.unpacked/$f"
  fi
done

# ---------------------------------------------------------------------------
# 7. Integrity hash = SHA256 of asar headerString (not the whole file)
# ---------------------------------------------------------------------------
log "Step 7: computing integrity hash..."
NEW_HASH="$(NODE_PATH="$NPX_ASAR" node -e "
  const a=require('@electron/asar'),c=require('crypto');
  process.stdout.write(c.createHash('sha256').update(a.getRawHeader(process.argv[1]).headerString).digest('hex'));
" "$WORK/app.asar.new")"
log "  hash: $NEW_HASH"

# ---------------------------------------------------------------------------
# 8. Install into the staged app under /tmp
# ---------------------------------------------------------------------------
log "Step 8: applying patch inside $STAGE ..."
cp "$WORK/app.asar.new" "$ASAR"
rm -rf "$UNPACKED"
cp -R "$WORK/app.asar.new.unpacked" "$UNPACKED"
/usr/libexec/PlistBuddy -c \
  "Set :ElectronAsarIntegrity:Resources/app.asar:hash $NEW_HASH" "$PLIST"

# ---------------------------------------------------------------------------
# 9. Ad-hoc re-sign under /tmp (no App Management restriction)
# ---------------------------------------------------------------------------
log "Step 9: clearing xattrs and ad-hoc signing..."
xattr -cr "$STAGE" 2>/dev/null || true
codesign --force --deep --sign - --timestamp=none "$STAGE"
codesign -v --verbose=2 "$STAGE" && log "  Signature OK (ad-hoc)"

# ---------------------------------------------------------------------------
# 10. Swap into /Applications (needs App Management; Finder fallback)
# ---------------------------------------------------------------------------
log "Step 10: swapping into /Applications ..."
if rm -rf "$APP" 2>/dev/null && cp -R "$STAGE" "$APP" 2>/dev/null; then
  xattr -cr "$APP" 2>/dev/null || true
  codesign -v "$APP" && log "  Installed to /Applications and verified"
  rm -rf "$WORK"
  log "Done. Open Codex; the model picker should show your third-party model name."
  log "Backup dir: $BAK_DIR"
  log "Restore: bash $0 restore"
else
  rm -rf "$WORK"
  err "Could not write /Applications: this terminal lacks App Management permission."
  err "sudo will not help; this is TCC, not Unix permissions."
  err "Staged build is ready at: $STAGE"
  err ""
  err "Finish install with one of:"
  err "  (a) System Settings → Privacy & Security → App Management"
  err "      enable this terminal, fully quit and reopen it, then re-run,"
  err "      or run: bash $(dirname "$0")/install-patched-codex.sh"
  err "  (b) Finder: quit ChatGPT → move /Applications/ChatGPT.app to Trash"
  err "      → drag /tmp/ChatGPT.app into /Applications → open and verify."
  exit 2
fi