Do not use externalUserId as a public runtime lookup key from shipped clients.
JavaScript Setup
Install, validate, and configure the reference JavaScript SDK.
This is the shortest path to a real Persistly integration. Use the public JavaScript SDK repo, validate the pinned contract bundle, and start with a ps_test_ runtime key.
Install
Install the public JavaScript package instead of building from a private checkout.
npm install @persistly/sdk-js
Package
Use the public package and repository as the integration source of truth.
Package: @persistly/sdk-js | Repository: https://github.com/persistly/persistly-sdk-js
Avoid These Mistakes
Set the integration boundary correctly from the first commit.
Do not treat runtime keys as privileged admin secrets.
Do not invent slot_id semantics at the platform layer; put save-selection labels in metadata instead.