codex-model.sh

#!/usr/bin/env bash
# codex-model-switch — toggle the OpenAI Codex CLI/App between a LOCAL model
# (Ollama / any OpenAI-compatible provider) and the NATIVE cloud model.
#
#   https://github.com/cnvipstar/codex-model-switch        MIT License
#
# Usage:
#   codex-model                  Interactive menu (lists installed local + cloud models)
#   codex-model local  [MODEL]   Switch to a local provider model   (default: $CODEX_MODEL_DEFAULT_LOCAL)
#   codex-model native [MODEL]   Switch back to Codex native cloud   (default: $CODEX_MODEL_DEFAULT_NATIVE)
#   codex-model status           Show the current mode
#   codex-model -h | --help      Show this help
#
# Only the top-level keys  model / model_provider / oss_provider  in config.toml are rewritten;
# everything else (projects, MCP servers, plugins, desktop settings, …) is preserved untouched.
# Every switch writes atomically and keeps a timestamped backup next to config.toml.

set -euo pipefail

CONFIG="${CODEX_HOME:-$HOME/.codex}/config.toml"
CODEX_DIR="$(dirname "$CONFIG")"
LOCAL_API_BASE="${CODEX_MODEL_LOCAL_API:-http://localhost:11434/v1}"   # OpenAI-compatible endpoint
PROVIDER_ID="${CODEX_MODEL_PROVIDER_ID:-ollama}"                        # value written to model_provider
OSS_PROVIDER="${CODEX_MODEL_OSS_PROVIDER:-ollama}"                      # value written to oss_provider
DEFAULT_LOCAL="${CODEX_MODEL_DEFAULT_LOCAL:-gpt-oss:20b}"
DEFAULT_NATIVE="${CODEX_MODEL_DEFAULT_NATIVE:-gpt-5.5}"

die(){ echo "❌ $*" >&2; exit 1; }

usage(){
  awk 'NR==1{next} /^#/{sub(/^# ?/,""); print; next} {exit}' "$0"
}

[ -f "$CONFIG" ] || die "config.toml not found at: $CONFIG  (set CODEX_HOME if it lives elsewhere)"

# ── List local models from the OpenAI-compatible /models endpoint (works for Ollama & LM Studio) ──
list_local_models(){
  curl -sf "$LOCAL_API_BASE/models" 2>/dev/null \
    | python3 -c "import sys,json;[print(x.get('id','')) for x in json.load(sys.stdin).get('data',[])]" 2>/dev/null \
    || true
}

# ── Show current mode ──
show_status(){
  python3 - "$CONFIG" <<'PY'
import sys, re
lines = open(sys.argv[1], encoding='utf-8').read().split('\n')
top = []
for l in lines:
    if re.match(r'\s*\[', l): break
    top.append(l)
top = '\n'.join(top)
def g(k):
    m = re.search(rf'(?m)^\s*{k}\s*=\s*"([^"]*)"', top)
    return m.group(1) if m else None
model, prov = g('model'), g('model_provider')
if prov:
    print(f"current: 🖥  LOCAL   (model_provider={prov}, model={model})")
else:
    print(f"current: ☁️  NATIVE  (cloud, model={model})")
PY
}

# ── Apply a switch:  apply_switch <local|native> <model> ──
apply_switch(){
  local MODE="$1" MODEL="$2"

  if [ "$MODE" = "local" ]; then
    local models
    models="$(list_local_models)"
    if [ -z "$models" ]; then
      echo "⚠️  Local endpoint not reachable at $LOCAL_API_BASE — Codex won't be able to connect after switching."
    elif ! printf '%s\n' "$models" | grep -qxF "$MODEL"; then
      echo "⚠️  Model '$MODEL' not found at $LOCAL_API_BASE. Pull/load it first (e.g. 'ollama pull $MODEL') or check the name."
    fi
  fi

  local bak="$CONFIG.bak-codex-model-$(date +%Y%m%d-%H%M%S)"
  cp "$CONFIG" "$bak"

  python3 - "$CONFIG" "$MODE" "$MODEL" "$PROVIDER_ID" "$OSS_PROVIDER" <<'PY'
import sys, re, os
path, mode, model, provider_id, oss_provider = sys.argv[1:6]
lines = open(path, encoding='utf-8').read().split('\n')
first = len(lines)
for i, l in enumerate(lines):
    if re.match(r'\s*\[', l):
        first = i; break
top, rest = lines[:first], lines[first:]
# drop any existing top-level model / model_provider / oss_provider
top = [l for l in top if not re.match(r'\s*(model|model_provider|oss_provider)\s*=', l)]
new = [f'model = "{model}"']
if mode == 'local':
    new += [f'model_provider = "{provider_id}"', f'oss_provider = "{oss_provider}"']
out = '\n'.join(new + top + rest)
with open(path + '.tmp', 'w', encoding='utf-8') as f:
    f.write(out)
os.replace(path + '.tmp', path)
PY

  echo "✅ switched"
  show_status
  echo "📦 backup: $bak"
  if pgrep -f "Codex.app" >/dev/null 2>&1; then
    echo "🔁 Codex App is running — restart it (or open a new conversation) for the change to take effect."
  else
    echo "🔁 Takes effect next time Codex starts / on a new conversation."
  fi
}

# ── Interactive menu ──
interactive_menu(){
  echo "════════════ Codex model switch ════════════"
  show_status
  echo

  local -a names modes
  names=(); modes=()

  echo "── 🖥  Local ($LOCAL_API_BASE) ──"
  local local_list; local_list="$(list_local_models)"
  if [ -n "$local_list" ]; then
    while IFS= read -r m; do
      [ -z "$m" ] && continue
      names+=("$m"); modes+=("local")
      printf "  %2d) %s\n" "${#names[@]}" "$m"
    done <<< "$local_list"
  else
    echo "  (endpoint unreachable — start your local server, or use 'm' below)"
  fi

  echo "── ☁️  Codex native (cloud) ──"
  local native_list
  native_list="$(python3 - "$CODEX_DIR/models_cache.json" <<'PY' 2>/dev/null || true
import sys, json
try:
    d = json.load(open(sys.argv[1], encoding='utf-8'))
except Exception:
    sys.exit(0)
found = set()
def walk(o):
    if isinstance(o, dict):
        for k, v in o.items():
            if k in ('id', 'slug') and isinstance(v, str) and v.startswith('gpt-'):
                found.add(v)
            walk(v)
    elif isinstance(o, list):
        for v in o: walk(v)
walk(d)
for m in sorted(found): print(m)
PY
)"
  [ -z "${native_list:-}" ] && native_list=$'gpt-5.5\ngpt-5.4\ngpt-5.4-mini'
  while IFS= read -r m; do
    [ -z "$m" ] && continue
    names+=("$m"); modes+=("native")
    printf "  %2d) %s\n" "${#names[@]}" "$m"
  done <<< "$native_list"

  echo "  ───────────────"
  echo "   m) ✍️  enter a model name manually"
  echo "   q) cancel"
  echo
  printf "Select a number: "
  local choice; read -r choice

  case "$choice" in
    ""|q|Q) echo "cancelled, no changes."; exit 0;;
    m|M)
      printf "model name: "; local mm; read -r mm
      [ -z "$mm" ] && { echo "nothing entered, cancelled."; exit 0; }
      printf "type [1=local / 2=native cloud]: "; local mt; read -r mt
      case "$mt" in
        1) apply_switch local  "$mm";;
        2) apply_switch native "$mm";;
        *) die "invalid type: $mt";;
      esac
      ;;
    *[!0-9]*) die "invalid input: $choice";;
    *)
      local idx=$((choice-1))
      [ "$choice" -ge 1 ] 2>/dev/null && [ -n "${names[$idx]:-}" ] || die "number out of range: $choice"
      apply_switch "${modes[$idx]}" "${names[$idx]}"
      ;;
  esac
}

# ── Entry point ──
cmd="${1:-MENU}"
arg="${2:-}"
case "$cmd" in
  MENU)            interactive_menu;;
  status)          show_status;;
  local)           apply_switch local  "${arg:-$DEFAULT_LOCAL}";;
  native)          apply_switch native "${arg:-$DEFAULT_NATIVE}";;
  -h|--help|help)  usage;;
  *) die "unknown command: $cmd  (use: no-args = menu | local | native | status | --help)";;
esac