キャッシュとWebhookで転送量を抑えつつ最新表示

1. High traffic and data transfer

With cache + CDN, many users at once do not cause a big spike in microCMS data transfer.

Nitro serves most requests from cache; the CDN serves many before they even reach your server. So microCMS is only called when a cache entry is missing or revalidating.

2. Why use a Webhook?

Caching keeps transfer low but can delay when new content appears (e.g. up to 1 hour).

Webhook = “content changed in microCMS” → your app reacts (e.g. invalidate cache or rebuild) so the next request gets fresh data.

So you get both: low data transfer (cache) and fast content updates (webhook-triggered invalidation). That’s why microCMS Webhook is used.

3. What was added

docs/CACHE_AND_WEBHOOK.md – Short explanation of cache + webhook and how they work together.
POST /api/webhook – Webhook receiver that:
- Verifies x-microcms-signature with MICROCMS_WEBHOOK_SECRET
- Clears Nitro cache (list/article/featured-news) so the next request hits microCMS and returns fresh data
runtimeConfig.microcms.webhookSecret – Reads from MICROCMS_WEBHOOK_SECRET (server-only).

4. How to use it

In microCMS: API設定 → Webhook → カスタム通知 → URL: https://your-domain.com/api/webhook, set the same secret in “Webhookのセキュリティ保護”.
In your env: set MICROCMS_WEBHOOK_SECRET to that secret.
When you publish/update/delete content, microCMS POSTs to /api/webhook → cache is cleared → new article (and list) appear on the next request without waiting for cache TTL.

So: traffic spike is still handled by cache; new articles appear quickly because of the webhook.