The Qpid Proton C API enables writing clients and servers that send and receive messages using the AMQP protocol. It is part of the Qpid Proton suite of messaging APIs.


The @ref core module is a collection of types and functions representing AMQP concepts and key elements of the API. Together they form a “protocol engine” API to create AMQP @ref connection “connections” and @ref link “links”, handle @ref event “events”, and send and receive @ref message “messages”.

The @ref types module contains C types and functions for handling AMQP- and API-specific data types.

The @ref codec module has functions for AMQP data encoding and decoding.

The @ref io module contains interfaces for integrating with platform-native network IO. See @ref io_page for more information.


Elements of the API marked as Unsettled API, including any elements contained within them, are still evolving and thus are subject to change. They are available to use, but newer versions of Proton may require changes to your application source code.

Elements marked Deprecated are slated for removal in a future release.