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The client SDKs call the Core API. They handle request formatting and provide helpers for items, events, recommendations and search. The MCP server connects AI assistants to NSL. For a website that needs no custom backend, start with the Website embed. For other languages, use the REST API directly.

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Shared conventions

  • Item and context IDs are positive integers assigned by NSL. Event-type IDs are non-zero integers from your workspace. Do not substitute display names or your store’s SKU.
  • User IDs come from your application. Use the same identifier when requesting recommendations and sending events.
  • Request IDs identify a particular result set. Preserve each rail’s ID with its rendered items and send it explicitly with engagement events.
  • Session IDs group activity within a visit. A single SDK instance’s generated session is not a session for every user of your server.
  • Credentials belong on trusted servers. See Authentication before integrating a browser or mobile client.
The libraries do not expose identical methods. For example, Next.js uses recommendSets, while the other clients use getRecommendationSets. Each reference documents its own API and limits.

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Migrating an older integration

Read the integer ID migration guide if your code uses string item IDs or event names. Update stored mappings and event payloads before changing production traffic.