CDN setup

The public delivery endpoint is built to sit behind a CDN. The CDN absorbs read traffic; the origin only serves cache misses and revalidations.

i18n client ──▶ CDN (edge cache) ──▶ origin  GET /cdn/:slug/:locale/:ns(.json)
                     │                      │
                  by URL path        Translation::Artifact (Active Storage blob)
                                            └─ falls back to compiling live

Origin contract

DeliveryController already emits everything a CDN needs:

The ETag is derived from the compiled content, so it changes the instant a translation is published, unpublished, edited, or deleted. A client (or CDN) holding a stale copy gets a new body on its next revalidation.

Cloudflare configuration

Cache rule (or legacy Page Rule) matching the delivery path:

• Match: */cdn/*
• Cache eligibility: Eligible for cache
• Edge TTL: Use cache-control header from origin (honors max-age=3600)
• Browser TTL: Respect origin
• Cache key: URL path (no cookies, no query — the endpoint takes none)
• Leave Respect strong ETags / origin revalidation on, so If-None-Match is forwarded and 304s are honored.

No Worker is required for caching. stale-while-revalidate is honored natively.

Cache invalidation on publish

Two layers, in order of preference:

1. Automatic (no action needed). stale-while-revalidate=300 means a publish propagates within ~5 minutes everywhere, with no purge call. For most content this is enough.

2. Instant purge (optional). For zero-delay propagation, purge the specific URL when a Translation::Publication is created or its artifact is rebuilt. The targeted path is deterministic:

   https://<delivery-host>/cdn/<project-slug>/<locale-code>/<namespace-name>.json

   Cloudflare purge-by-URL:

   curl -X POST \
     "https://api.cloudflare.com/client/v4/zones/$CF_ZONE_ID/purge_cache" \
     -H "Authorization: Bearer $CF_API_TOKEN" \
     -H "Content-Type: application/json" \
     -d '{"files":["https://cdn.example.com/cdn/demo-app/en/common.json"]}'

   The natural trigger is Translation::Artifact.rebuild — it runs on exactly the content changes that need a purge. Wiring this as an outbound call belongs with the webhook/delivery-job work (#43): it needs retries, timeouts, and to run off the request path, plus the CF_ZONE_ID / CF_API_TOKEN secrets. Until then, layer 1 covers propagation.

Local / development

No CDN. Requests hit the origin directly; the same Cache-Control/ETag headers apply, so behavior matches production minus the edge cache.