Codex 作業完了を Slack 通知する

Codex には Claude Code の hooks 相当がないため、~/.codex/sessions を監視して assistant 応答を検知し、Slack Incoming Webhook に送る方式で実現します。

構成

• 監視スクリプト: ~/.codex/hooks/codex-watch-notify.sh
• 機密設定: ~/.codex/slack-notify.env
• 常駐: ~/Library/LaunchAgents/com.example.codex.slack-notify.plist
• 状態保存: ~/.codex/slack-notify-state/

1. Slack Incoming Webhook を作成

1. Slack API で Create New App を押す
2. From scratch を選択し、アプリ名と Workspace を指定
3. 左メニュー Incoming Webhooks を開く
4. Activate Incoming Webhooks を On にする
5. Add New Webhook から通知先チャンネルを選んで許可
6. 発行された Webhook URL を控える（https://hooks.slack.com/services/...）

2. Webhook を環境ファイルに保存

~/.codex/slack-notify.env を作成:

SLACK_WEBHOOK_URL="https://hooks.slack.com/services/XXX/YYY/ZZZ"

権限を絞る:

chmod 600 ~/.codex/slack-notify.env

3. 監視スクリプトを配置

~/.codex/hooks/codex-watch-notify.sh:

#!/bin/bash
set -euo pipefail

SESSIONS_DIR="${HOME}/.codex/sessions"
STATE_DIR="${HOME}/.codex/slack-notify-state"
LAST_SESSION_FILE="${STATE_DIR}/last_session_path"
LAST_LINE_FILE="${STATE_DIR}/last_line"
LAST_SENT_KEY_FILE="${STATE_DIR}/last_sent_key"
POLL_INTERVAL_SEC="${POLL_INTERVAL_SEC:-5}"
QUIET_SEC="${QUIET_SEC:-90}"
ENV_FILE="${HOME}/.codex/slack-notify.env"
PENDING_MESSAGE_FILE="${STATE_DIR}/pending_message"
PENDING_TITLE_FILE="${STATE_DIR}/pending_title"
PENDING_EPOCH_FILE="${STATE_DIR}/pending_epoch"

mkdir -p "${STATE_DIR}"
WEBHOOK_URL=""

load_webhook_url() {
  WEBHOOK_URL=""
  if [ -f "${ENV_FILE}" ]; then
    # shellcheck disable=SC1090
    . "${ENV_FILE}"
    WEBHOOK_URL="${SLACK_WEBHOOK_URL:-}"
    WEBHOOK_URL="$(printf '%s' "${WEBHOOK_URL}" | tr -d '\r')"
  fi
}

session_tail_path() {
  local latest_file=""
  local latest_mtime=0
  local file_path mtime
  while IFS= read -r -d '' file_path; do
    mtime="$(stat -f '%m' "${file_path}" 2>/dev/null || echo 0)"
    if [ "${mtime}" -gt "${latest_mtime}" ]; then
      latest_mtime="${mtime}"
      latest_file="${file_path}"
    fi
  done < <(find "${SESSIONS_DIR}" -type f -name "*.jsonl" -print0 2>/dev/null)
  printf '%s\n' "${latest_file}"
}

read_state() {
  LAST_SESSION_PATH=""
  LAST_LINE=0
  LAST_SENT_KEY=""
  PENDING_MESSAGE=""
  PENDING_TITLE=""
  PENDING_EPOCH=0

  [ -f "${LAST_SESSION_FILE}" ] && LAST_SESSION_PATH="$(cat "${LAST_SESSION_FILE}" 2>/dev/null || true)"
  [ -f "${LAST_LINE_FILE}" ] && LAST_LINE="$(cat "${LAST_LINE_FILE}" 2>/dev/null || echo 0)"
  [ -f "${LAST_SENT_KEY_FILE}" ] && LAST_SENT_KEY="$(cat "${LAST_SENT_KEY_FILE}" 2>/dev/null || true)"
  [ -f "${PENDING_MESSAGE_FILE}" ] && PENDING_MESSAGE="$(cat "${PENDING_MESSAGE_FILE}" 2>/dev/null || true)"
  [ -f "${PENDING_TITLE_FILE}" ] && PENDING_TITLE="$(cat "${PENDING_TITLE_FILE}" 2>/dev/null || true)"
  [ -f "${PENDING_EPOCH_FILE}" ] && PENDING_EPOCH="$(cat "${PENDING_EPOCH_FILE}" 2>/dev/null || echo 0)"
}

write_state() {
  printf '%s\n' "${CURRENT_SESSION_PATH}" > "${LAST_SESSION_FILE}"
  printf '%s\n' "${CURRENT_LINE_COUNT}" > "${LAST_LINE_FILE}"
  printf '%s\n' "${LAST_SENT_KEY}" > "${LAST_SENT_KEY_FILE}"
  printf '%s\n' "${PENDING_MESSAGE}" > "${PENDING_MESSAGE_FILE}"
  printf '%s\n' "${PENDING_TITLE}" > "${PENDING_TITLE_FILE}"
  printf '%s\n' "${PENDING_EPOCH}" > "${PENDING_EPOCH_FILE}"
}

notify_slack() {
  local message="$1"
  local title="$2"
  [ -z "${WEBHOOK_URL}" ] && return 0

  local ts payload
  ts="$(date "+%Y-%m-%d %H:%M:%S")"
  payload="$(
    jq -n \
      --arg text "🔔 ${title}" \
      --arg msg "${message}" \
      --arg time "${ts}" \
      '{
        text: $text,
        attachments: [{
          color: "good",
          fields: [
            { title: "Message", value: $msg, short: false },
            { title: "Time", value: $time, short: true }
          ]
        }]
      }'
  )"

  curl -sS -X POST \
    -H "Content-Type: application/json" \
    -d "${payload}" \
    "${WEBHOOK_URL}" >/dev/null 2>&1 || true
}

queue_notification() {
  local message="$1"
  local title="$2"
  PENDING_MESSAGE="${message}"
  PENDING_TITLE="${title}"
  PENDING_EPOCH="$(date +%s)"
}

flush_notification_if_quiet() {
  [ -z "${PENDING_MESSAGE}" ] && return 0
  local now
  now="$(date +%s)"
  if [ $((now - PENDING_EPOCH)) -ge "${QUIET_SEC}" ]; then
    notify_slack "${PENDING_MESSAGE}" "${PENDING_TITLE:-Codex: response ready}"
    PENDING_MESSAGE=""
    PENDING_TITLE=""
    PENDING_EPOCH=0
  fi
}

extract_notifications() {
  local file_path="$1"
  local start_line="$2"
  tail -n +"$((start_line + 1))" "${file_path}" 2>/dev/null | jq -cr '
    select(.type == "response_item")
    | select(.payload.type == "message")
    | select(.payload.role == "assistant")
    | .payload as $p
    | ($p.content // []) as $content
    | ($content[]? | select(.type == "output_text") | .text) as $text
    | select($text != null and $text != "")
    | { ts: (.timestamp // ""), text: $text }
  ' 2>/dev/null
}

while true; do
  load_webhook_url
  read_state
  CURRENT_SESSION_PATH="$(session_tail_path)"
  if [ -z "${CURRENT_SESSION_PATH}" ] || [ ! -f "${CURRENT_SESSION_PATH}" ]; then
    sleep "${POLL_INTERVAL_SEC}"
    continue
  fi

  CURRENT_LINE_COUNT="$(wc -l < "${CURRENT_SESSION_PATH}" | tr -d ' ')"
  START_LINE="${LAST_LINE}"
  [ "${CURRENT_SESSION_PATH}" != "${LAST_SESSION_PATH}" ] && START_LINE=0
  [ "${CURRENT_LINE_COUNT}" -lt "${START_LINE}" ] && START_LINE=0

  if [ "${CURRENT_LINE_COUNT}" -gt "${START_LINE}" ]; then
    while IFS= read -r row; do
      [ -z "${row}" ] && continue
      ts="$(echo "${row}" | jq -r '.ts')"
      text="$(echo "${row}" | jq -r '.text')"
      first_line="$(printf '%s' "${text}" | tr '\n' ' ' | sed -E 's/[[:space:]]+/ /g' | cut -c1-180)"
      notify_key="${CURRENT_SESSION_PATH}|${ts}|${first_line}"
      [ "${notify_key}" = "${LAST_SENT_KEY}" ] && continue
      queue_notification "${first_line}" "Codex: response ready"
      LAST_SENT_KEY="${notify_key}"
    done < <(extract_notifications "${CURRENT_SESSION_PATH}" "${START_LINE}")
  fi

  flush_notification_if_quiet
  write_state
  sleep "${POLL_INTERVAL_SEC}"
done

実行権限:

chmod +x ~/.codex/hooks/codex-watch-notify.sh

4. launchd で常駐

~/Library/LaunchAgents/com.example.codex.slack-notify.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>com.example.codex.slack-notify</string>
  <key>ProgramArguments</key>
  <array>
    <string>/bin/bash</string>
    <string>/Users/<your_username>/.codex/hooks/codex-watch-notify.sh</string>
  </array>
  <key>RunAtLoad</key><true/>
  <key>KeepAlive</key><true/>
  <key>WorkingDirectory</key><string>/Users/<your_username></string>
  <key>StandardOutPath</key><string>/Users/<your_username>/.codex/log/codex-watch-notify.log</string>
  <key>StandardErrorPath</key><string>/Users/<your_username>/.codex/log/codex-watch-notify.err.log</string>
  <key>EnvironmentVariables</key>
  <dict>
    <key>PATH</key><string>/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin</string>
    <key>POLL_INTERVAL_SEC</key><string>5</string>
    <key>QUIET_SEC</key><string>90</string>
  </dict>
</dict>
</plist>

起動:

launchctl bootstrap gui/$(id -u) ~/Library/LaunchAgents/com.example.codex.slack-notify.plist
launchctl kickstart -k gui/$(id -u)/com.example.codex.slack-notify

停止:

launchctl bootout gui/$(id -u) ~/Library/LaunchAgents/com.example.codex.slack-notify.plist

状態確認:

launchctl print gui/$(id -u)/com.example.codex.slack-notify

5. 連投抑制の考え方

• POLL_INTERVAL_SEC=5: 5秒ごとにセッションを監視
• QUIET_SEC=90: 最終応答から90秒静止した時点で1件だけ通知
• SLACK_WEBHOOK_URL: ループごとに再読込（slack-notify.env 更新を再起動なしで反映）

このため、短時間に何度も応答が返る場合でも Slack には最後の要約1件だけが届きます。

6. 注意点

• Webhook URL を Git 管理ファイルに含めない
• セッション先頭テキストを送る設計なので、機密情報の取り扱いに注意
• Codex 側 JSON 形式変更時は jq 抽出条件の見直しが必要