Examples

These examples show complete Cache patterns you can adapt inside Layeron route handlers.

API Response Cache

Cache a public list endpoint and purge it after writes.

const apiCache = cache({
  name: "public-api",
  ttlSeconds: 60,
  tags: ["products"],
})

app.use(apiCache)

app.get("/api/products", async (request) => {
  const cached = await apiCache.match(request)

  if (cached) {
    return cached
  }

  const products = await listProducts()
  const response = Response.json({ products })

  await apiCache.put(request, response.clone(), {
    tags: ["products"],
  })

  return response
})

app.post("/api/products", async (request) => {
  const input = await request.json()
  const product = await createProduct(input)

  await apiCache.purge({
    tags: ["products"],
  })

  return Response.json({ product }, { status: 201 })
})

Detail Page With Precise Tags

Attach list and item tags to detail responses.

app.get("/api/products/:id", async (request) => {
  const pathSegments = new URL(request.url).pathname.split("/")
  const id = pathSegments[3]
  const cached = await apiCache.match(request)

  if (cached) {
    return cached
  }

  const product = await findProduct(id)

  if (!product) {
    return Response.json({ error: "Missing product" }, { status: 404 })
  }

  const response = Response.json({ product })

  await apiCache.put(request, response.clone(), {
    tags: ["products", `product:${id}`],
    ttlSeconds: 120,
  })

  return response
})

app.patch("/api/products/:id", async (request) => {
  const pathSegments = new URL(request.url).pathname.split("/")
  const id = pathSegments[3]
  const input = await request.json()
  const product = await updateProduct(id, input)

  await apiCache.purge({
    tags: ["products", `product:${id}`],
  })

  return Response.json({ product })
})

Localized Content

Use vary when the same path can produce different languages.

const contentCache = cache({
  name: "content",
  ttlSeconds: 300,
  vary: ["accept-language"],
})

app.use(contentCache)

app.get("/api/homepage", async (request) => {
  const cached = await contentCache.match(request)

  if (cached) {
    return cached
  }

  const language = request.headers.get("accept-language") ?? "en"
  const page = await loadHomepage(language)
  const response = Response.json({ page })

  await contentCache.put(request, response.clone(), {
    tags: ["homepage"],
  })

  return response
})

Webhook-Driven Invalidation

Purge cached content after a CMS or commerce webhook.

app.post("/webhooks/catalog", async (request) => {
  const event = await verifyCatalogWebhook(request)

  if (event.type === "product.updated") {
    await apiCache.purge({
      tags: ["products", `product:${event.productId}`],
    })
  }

  if (event.type === "catalog.rebuilt") {
    await apiCache.purge({
      tags: ["products"],
    })
  }

  return Response.json({ ok: true })
})