Watchlist API key features

Caplin Trader’s Watchlist API introduces a new model for managing watchlists that enables watchlists to be synchronised in real time between a user’s devices.

The new model has moved responsibility for the persistence of watchlist configurations from Webcentric to Transformer, from where they may be shared in real time between supporting StreamLink clients.

The two watchlist models contrasted

The table below contrasts the original Webcentric-persisted model with the new Transformer-persisted model.

Webcentric-Persisted Watchlists Transformer-Persisted Watchlists

Client-side interface

Webcentric’s layout XML

Watchlist API

Persistence store

Webcentric’s layout XML and the Webcentric database.

Private containers hosted on Transformer and persisted by Transformer’s Persistence Service.

Role of Webcentric

Webcentric stores the full definition of a watchlist within the layout XML of a Grid.

Webcentric stores only the ID of the Transformer-hosted watchlist within the layout XML of a Grid.

Role of Transformer

Transformer hosts a watchlist’s content in a temporary container that exists only for the duration that the watchlist is displayed in a Grid

Transformer hosts a watchlist’s metadata and content in containers that are persistent across user sessions and server restarts

When watchlists are persisted

When the Webcentric layout is saved by the user


Lifespan of a watchlist’s subject container on Transformer

Temporary. Exists for the duration of the user session only.

Permanent. A watchlist persists across user sessions until the user deletes the watchlist.

Namespace of watchlist containers on Transformer



Client support

Caplin Trader only

Any StreamLink client with support for Transformer-persisted watchlists

When watchlist configurations are read by Caplin Trader

Once, when the Webcentric layout is loaded

Clients subscribe to live configurations on Transformer and receive updates in real time

See also: