Which of the API family offering allows me to get the latest spot quote for foreign exchange USD to SGD? That means I can tap in the event of a new spot price quote, not historical data.
You can get the latest quote using Eikon Data APIs (Beta), but only as snapshot currently. The capability to subscribe to streaming data and receive quote updates is currently available through Eikon COM and .NET APIs. This capability will be added to Eikon Data APIs, but there's not committed time frame for it yet.