The Solace PubSub+ Messaging API for C, version 7.29.0 (also referred to as SolClient) is specifically designed to provide high message throughput and low latency with the lowest CPU utilization possible. In addition to the common Enterprise API features, the PubSub+ Messaging API for C enables fine-grained control of threading and message processing through additional features like:

  • Allows fine-tuning of API behavior, such as whether operations should be blocking or non-blocking in nature.
  • Allows for the option of application file descriptors to be monitored within the API, providing the application with callbacks for readable and writable events.
  • Allows for the option of the application taking over control of file descriptors created within the API to connect to event brokers, where the application must provide readable and writable events to the API.
  • Support for timer services.

Message Exchange Patterns

The PubSub+ Messaging API for C supports all common message exchange patterns.

  • Publish / Subscribe
  • Point-to-Point
  • Request / Reply

For more information, see Message Exchange Patterns.


For the list of features that are supported for the PubSub+ Messaging API for C, see the C column in the table in Feature Support in PubSub+ Messaging APIs.

Support for Solaris/SunOS is now deprecated and the last release was v7.23.0 (September 2022). For more details, see the Deprecated Features list on the Product Lifecycle Policy page.

Get Started

These tutorials introduce you to developing applications using the C API, and will get you up-to-speed and sending messages with Solace technology as quickly as possible. They cover common messaging requirements such as pub/sub.

There are three ways you can get started using a PubSub+ event broker:

  1. If you have PubSub+ event brokers already deployed, obtain the hostname or IP address of an event broker to test against, a username and password to access it, and a Message VPN in which you can produce and consume messages.
  2. You can set up a software event broker as a container or machine image. For more information, see one of the following:
  3. You can spin up an event broker service, which is a SaaS-based software event broker running in PubSub+ Cloud.

Start Tutorials

C API Reference

Click below to access the developer reference for the Solace PubSub+ Messaging API for C.

C API Reference

C API Release Notes

Click below to download the latest release notes for the Solace PubSub+ Messaging API for C.

C API Release Notes