Which API is optimized for Chatter objects in Salesforce?

The Chatter REST API is specifically designed to facilitate interactions with Chatter data and objects within Salesforce. This API provides endpoints that are tailored for accessing Chatter feeds, users, groups, and other related components, making it ideal for applications that need to work closely with Chatter features.

By optimizing for Chatter objects, this API allows developers to perform actions such as posting updates, commenting on posts, and managing notifications efficiently. The RESTful nature of the API ensures that it is lightweight and easy to use, which aligns well with the needs of applications that integrate social features within Salesforce.

The other options are not specifically optimized for Chatter. The Web Services API is a more general-purpose API that provides access to standard and custom objects, while the Bulk API is designed for handling large volumes of data efficiently, particularly for data import and export tasks. Custom Web Services may be created to suit specific needs but do not inherently provide the specialized capabilities that the Chatter REST API offers for managing Chatter-specific interactions effectively.