Cumulocity

Cumulocity MQTT Service API

Standards-compliant, multi-tenant MQTT broker for application-level messaging that does not need Cumulocity's domain model. Topics are tenant-scoped, persistent, and bridgeable to the Cumulocity domain model via the Dynamic Mapper. Use it as a general-purpose MQTT broker inside your Cumulocity tenant.

Cumulocity MQTT Service API is one of 19 APIs that Cumulocity publishes on the APIs.io network, described by an AsyncAPI event-driven specification.

This API exposes 1 machine-runnable capability that can be deployed as REST, MCP, or Agent Skill surfaces via Naftiko.

Tagged areas include IoT, MQTT, Streaming, and Application Integration. The published artifact set on APIs.io includes API documentation, an AsyncAPI specification, and 1 Naftiko capability spec.

GitHub

Documentation

📖
Documentation
https://cumulocity.com/docs/device-integration/mqtt-service/

Specifications

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AsyncAPI
https://raw.githubusercontent.com/api-evangelist/cumulocity/refs/heads/main/asyncapi/cumulocity-mqtt-service-asyncapi.yml

Other Resources

🔗
NaftikoCapability
https://raw.githubusercontent.com/api-evangelist/cumulocity/refs/heads/main/capabilities/mqtt-service-topics.yaml

AsyncAPI Specification

cumulocity-mqtt-service-asyncapi.yml Raw ↑ 
asyncapi: 2.6.0
info:
  title: Cumulocity MQTT Service
  version: 2025.1
  description: |
    Standards-compliant, multi-tenant MQTT broker for application-level messaging that does not need
    Cumulocity's domain model. Topics are tenant-scoped, persistent, and bridgeable to the Cumulocity
    domain model via the Dynamic Mapper.
servers:
  production:
    url: 'mqtt.{tenant}.cumulocity.com:8883'
    protocol: mqtts
    description: TLS-secured multi-tenant MQTT 5.0 broker.
    variables:
      tenant:
        default: example
    security:
    - basicAuth: []
defaultContentType: application/json
channels:
  '{tenantId}/{topic}':
    description: Tenant-scoped topic hierarchy for arbitrary application messages. Topics are isolated per tenant
      and persisted; subscribers receive missed messages on reconnect when using MQTT 5.0 session expiry.
    parameters:
      tenantId:
        schema: {type: string}
      topic:
        schema: {type: string}
    publish:
      operationId: publishGeneric
      summary: Publish to a tenant-scoped MQTT topic.
      message:
        $ref: '#/components/messages/GenericMessage'
    subscribe:
      operationId: subscribeGeneric
      summary: Subscribe to a tenant-scoped MQTT topic.
      message:
        $ref: '#/components/messages/GenericMessage'
components:
  messages:
    GenericMessage:
      name: genericMessage
      title: Generic MQTT Message
      summary: Arbitrary application payload published on a tenant-scoped topic.
      payload:
        oneOf:
        - type: object
          additionalProperties: true
        - type: string
  securitySchemes:
    basicAuth:
      type: userPassword