Liberator’s functions and features

Access to data

With Liberator you can access a wide variety of sources of data and external systems, including pricing information, trading, and permissioning systems. Just use the Caplin Integration Suite to implement one or more Integration Adapters that connect to your external systems and data feeds, and then connect Liberator to the Adapters.

Active subscriptions

Your client applications can subscribe to just the data they are interested in by sending requests to Liberator. Liberator manages the subscriptions and reliably sends the subscribing clients updates to the data over the Internet in real-time with very low latency.

Client publishing

With appropriate permissions, client applications can also publish data back to Liberator for onward transmission to other subscribing clients and external systems.

For more, see Client publication.

Trade messaging

Liberator’s bi-directional messaging capability allows your client applications to trade with external trading systems. Liberator handles the flow of trade messages between the clients and the trading systems (via Trading Adapters).

For more, see Trade messaging.

Supported data types

Liberator has in-built support for financial data types, such as:

For more, see Data types.

Data caching

Liberator caches data so that when multiple clients subscribe to the same subjects, the data is supplied efficiently to the clients. Overall network traffic is reduced, because clients don’t connect directly to the sources of data (only Liberator has these connections), and Liberator only subscribes to a source once for a given subject.

Performance and scalability

Liberator can handle many thousands of concurrent users, and its high performance publishing engine can deliver hundreds of thousands of updates per second from a single server. The latency of data delivery can be critical in trading platforms; Liberator’s designed to keep message latency as low as possible.

For more, see Performance.


Liberator is highly configurable and is blade-ready. The Caplin Deployment Framework comes with a number of built-in Config blades.

For more, see Configuration and blades.

Resilience and failover

Liberator can participate in a resiliently configured Platform architecture, providing a highly available service - clients can fail over to alternative Liberator instances, and Liberators can fail over to alternative Transformer and Integration Adapter instances.

User authentication and permissioning

Liberator supports a modular system for authenticating users and permissioning them (granting users permission to access data). Using Caplin KeyMaster you can set up Liberator to participate in your single sign-on system. KeyMaster creates secure authentication tokens (user credentials tokens) and Liberator use these to authenticate login requests. This method works with any single sign on system.

Throttling and batching

You can use these techniques to reduce the amount of data that Liberator sends to a client when the client application subscribes to a lot of data, or the data rate is very high, Throttling restricts the rate at which updates are sent to the client. Batching (also called bursting) concatenates messages together into larger packets containing multiple messages. You can configure throttling and batching to meet your requirements.

For more, see Throttling and Bursting.

Monitoring and management

Liberator logs comprehensive information about its run-time operation. Additionally, if you configure JMX, you can monitor and manage Liberator operation through a management application such as the Caplin Management Console.

For more, see Monitoring and management.


You can configure Liberator as a node within a cluster of Liberators. The clustered Liberators share information about the number of licences, users logged on, and information about data and subscriptions.

For more, see Clustering.

Licence management

Liberator manages the user-based licencing scheme for the Caplin Platform.

For more, see Licence management.

Development tools

Liberator comes with a local web site that enables you to monitor Liberator usage, view or download documentation for the Liberator and associated components, and view demonstration applications that use the StreamLink JS API. You also get the Liberator Explorer diagnostic tool, which allows you to quickly and easily inspect the values of the objects being managed by the Liberator.