Also viewed

GET /recommendations/also-viewed returns items that other users viewed in the same session as the seed item. Backed by precomputed co-view co-occurrence — not semantic similarity.

Request

GET /recommendations/also-viewed?indexId=<id>&itemId=<id>&limit=10
Authorization: Bearer <api-key>

Param	Type	Required	Notes
`indexId`	string	yes	Source index.
`itemId`	string	yes	Seed item.
`limit`	number	no	1–50, default 10.

Response

{
  "items": [
    { "id": "sku-9001", "score": 142, "data": { ... } }
  ],
  "anchorId": "sku-0001",
  "engine": "also-viewed"
}

score is the raw co-view count over the trailing window (default 30 days).

When to use

PDP "Customers also viewed" rail — Classic ecommerce surface; complements similar (semantic) with behavioural data.
Search results dwell page — When a user views one result, suggest others people clicked from the same query.

If the seed item has no co-view history (< 10 sessions), the engine falls back to Trending within the same category. The response's engine field will be "trending" in that case — branch your UI on it if you want different labelling.

Latency

p95 ~50 ms on Pro. The co-occurrence map is precomputed nightly; the API is a hash lookup.

Code path

packages/api/modules/recommendations/procedures/also-viewed.ts.