Cumulocity is pleased to announce that the Cumulocity MQTT Service is now generally available.
The MQTT Service provides a single, unified endpoint for integrating MQTT devices with the Cumulocity platform that is simple, secure, and scalable.
Simple
- Connect any MQTT device with any payload and topic structure, using MQTT version 3.1.1 or 5.0.
- Devices using the Cumulocity core MQTT protocols, SmartREST and JSON-over-MQTT, are supported alongside generic devices with their own application-layer protocols.
Secure
- Full device isolation and bi-directional TLS support by default.
- Works with the Cumulocity Certificate Authority, or with your existing external CA.
Scalable
- Optimized for high message throughput with large numbers of connected devices.
- Validated with 100 million connected devices publishing 1 million unique messages per second.
See the user documentation for more details of the MQTT Service architecture and how to integrate your devices and applications with it.
Availability
The MQTT Service is available to all tenants in Cumulocity environments following the Continuous Delivery (CD) release line, and in the 2026 annual release.
Usage of the service is billable, as described in the license metrics documentation.
Per-tenant usage quotas are enforced to ensure reliable operation of Cumulocity’s shared environments.
These quotas can be adjusted to support larger use cases in shared and dedicated environments.
See service quotas for details of the applicable quotas.
Migrating from the Public Preview
Some features were deprecated and replaced during the Public Preview of the MQTT Service.
These features are not supported after the transition to General Availability.
Users migrating from the Public Preview must ensure that all their applications and devices have been updated to use only Generally Available features.
See the previous announcement for details of these features that have been removed:
- Tenant-level isolation
- MQTT Service Java client SDK
- Non-TLS endpoint on shared environments
- Basic authentication for users without the Mqtt-service ADMIN permission
Limitations
The first generally available release of the MQTT Service has some limitations that will be addressed in future updates:
- Support for Core MQTT devices using SmartREST or JSON-over-MQTT is still in Public Preview status and subject to breaking changes before it becomes generally available.
See Core MQTT device support for details of these specific limitations:
- Structured client identifiers allowed by the Cumulocity core MQTT endpoint are not supported.
- Pending operations must be explicitly requested by a device when it connects.
- Messages may be acknowledged by the MQTT Service before they have been processed by the Cumulocity core.
- Devices are not automatically disconnected after sending invalid Core MQTT messages.
- Availability monitoring is not supported for “push connection” traffic to devices.
- The “delivery” fragment on an operation is not updated after the operation is delivered to the device.
- WebSocket connections to the MQTT Service are not supported.
- Retained messages are not supported.
- Last Will messages are not sent when devices disconnect from the MQTT Service.
- Messages using the Correlation Data field are not forwarded to the Messaging Service.
