Azure Event Hubs

Technical Preview

Overview

A client-mode connector that forwards broker data into Azure Event Hubs over the runtime REST send API. Use it to stream plant telemetry into Azure analytics (Stream Analytics, Fabric Real-Time Intelligence, Data Explorer, Databricks) without running an AMQP or Kafka client.

Event	Request	Notes
SendEvent	`POST /{hub}/messages`	One event; `application/atom+xml;type=entry;charset=utf-8`
SendEventWithPartitionKey	`POST /{hub}/messages` + `BrokerProperties`	Same key lands on the same partition (ordered per device)
SendPartitionEvent	`POST /{hub}/partitions/{id}/messages`	Explicit partition
SendBatch	`POST /{hub}/messages`	JSON array of `{"Body", "UserProperties"}`; `application/vnd.microsoft.servicebus.json`

Every request uses api-version=2014-01 and returns 201 Created with an empty body. Default BASE_ADDRESS is https://YOUR_NAMESPACE.servicebus.windows.net (no trailing slash). Topics use data/azure-event-hubs/<object>/<verb>. See the base guide: REST API Connectors.

Auth: pass the full Authorization value as {value.json.authorization}, either SharedAccessSignature sr=…&sig=…&se=…&skn=… from a policy with the Send claim, or Bearer {entra_token} (scope https://eventhubs.azure.net/.default, role Azure Event Hubs Data Sender). Prefer Hub secrets; never commit keys into the .lot.

Send only. Event Hubs has no REST receive API; consumers use AMQP or Kafka. The management plane (creating namespaces and hubs) goes through Azure Resource Manager and is not packaged. A Fabric Eventstream custom endpoint exposes an Event Hubs-compatible namespace and SAS key, so the same template applies. This template has not yet been verified against a live namespace.

Basic Syntax

DEFINE ROUTE AzureEventHubsRestApi WITH TYPE REST_API
    ADD REST_API_CONFIG
        WITH BASE_ADDRESS "https://YOUR_NAMESPACE.servicebus.windows.net"
        WITH ENABLE_CLIENT "true"
        WITH USE_SSL "true"
        WITH REQUEST_TIMEOUT '60'
        WITH DEFAULT_CONTENT_TYPE "application/json"
        # Auth: SAS or Entra Bearer via {value.json.authorization} (see header comments). Never commit real keys.
    ADD EVENT SendEvent
        WITH SOURCE_TOPIC "data/azure-event-hubs/messages/post"
        WITH DESTINATION_TOPIC "data/azure-event-hubs/messages/post/response"
        WITH METHOD "POST"
        WITH ENDPOINT "/{value.json.hub}/messages?timeout=60&api-version=2014-01"
        WITH HEADERS
            ADD "Content-Type" "application/atom+xml;type=entry;charset=utf-8"
            ADD "Authorization" "{value.json.authorization}"
        WITH BODY "{value.json.body}"
    ADD EVENT SendEventWithPartitionKey
        WITH SOURCE_TOPIC "data/azure-event-hubs/messages/keyed/post"
        WITH DESTINATION_TOPIC "data/azure-event-hubs/messages/keyed/post/response"
        WITH METHOD "POST"
        WITH ENDPOINT "/{value.json.hub}/messages?timeout=60&api-version=2014-01"
        WITH HEADERS
            ADD "Content-Type" "application/atom+xml;type=entry;charset=utf-8"
            ADD "Authorization" "{value.json.authorization}"
            ADD "BrokerProperties" "{value.json.broker_properties}"
        WITH BODY "{value.json.body}"
    ADD EVENT SendPartitionEvent
        WITH SOURCE_TOPIC "data/azure-event-hubs/partitions/messages/post"
        WITH DESTINATION_TOPIC "data/azure-event-hubs/partitions/messages/post/response"
        WITH METHOD "POST"
        WITH ENDPOINT "/{value.json.hub}/partitions/{value.json.partition_id}/messages?timeout=60&api-version=2014-01"
        WITH HEADERS
            ADD "Content-Type" "application/atom+xml;type=entry;charset=utf-8"
            ADD "Authorization" "{value.json.authorization}"
        WITH BODY "{value.json.body}"
    ADD EVENT SendBatch
        WITH SOURCE_TOPIC "data/azure-event-hubs/messages/batch/post"
        WITH DESTINATION_TOPIC "data/azure-event-hubs/messages/batch/post/response"
        WITH METHOD "POST"
        WITH ENDPOINT "/{value.json.hub}/messages?timeout=60&api-version=2014-01"
        WITH HEADERS
            ADD "Content-Type" "application/vnd.microsoft.servicebus.json"
            ADD "Authorization" "{value.json.authorization}"
        WITH BODY "{value.json.body}"

MQTT examples

SendEvent (data/azure-event-hubs/messages/post), expect 201 Created with an empty body:

{
  "hub": "press-telemetry",
  "authorization": "SharedAccessSignature sr=https%3A%2F%2FYOUR_NAMESPACE.servicebus.windows.net%2Fpress-telemetry&sig=...&se=1767225600&skn=coreflux-send",
  "body": {
    "DeviceId": "press-01",
    "Temperature": 37.0,
    "ts": "2026-10-05T00:21:00Z"
  }
}

SendEventWithPartitionKey (data/azure-event-hubs/messages/keyed/post), expect 201 Created with an empty body:

{
  "hub": "press-telemetry",
  "authorization": "SharedAccessSignature sr=...&sig=...&se=...&skn=coreflux-send",
  "broker_properties": "{\"PartitionKey\":\"press-01\"}",
  "body": {
    "DeviceId": "press-01",
    "rpm": 1450
  }
}

SendPartitionEvent (data/azure-event-hubs/partitions/messages/post), expect 201 Created with an empty body:

{
  "hub": "press-telemetry",
  "partition_id": "0",
  "authorization": "SharedAccessSignature sr=...&sig=...&se=...&skn=coreflux-send",
  "body": {
    "DeviceId": "press-02",
    "state": "RUN"
  }
}

SendBatch (data/azure-event-hubs/messages/batch/post), expect 201 Created with an empty body:

{
  "hub": "press-telemetry",
  "authorization": "Bearer <entra_access_token>",
  "body": [
    {
      "Body": "{\"DeviceId\":\"press-01\",\"t\":37.1}",
      "UserProperties": {
        "line": "A"
      }
    },
    {
      "Body": "{\"DeviceId\":\"press-02\",\"t\":36.8}"
    }
  ]
}

body becomes the HTTP body, so control fields (hub, authorization, partition_id, broker_properties) are never sent to Azure.

Generating a SAS token

The signature is HMAC-SHA256(key, url_encode(resource_uri) + "\n" + expiry), base64-encoded and URL-encoded. With Azure CLI you can read the policy key:

az eventhubs eventhub authorization-rule keys list -g YOUR_RG --namespace-name YOUR_NAMESPACE --eventhub-name press-telemetry -n coreflux-send

Then build the token with the snippet from Generate SAS token. Keep expiry short and rotate through Hub secrets.

Notes

Replace YOUR_NAMESPACE in BASE_ADDRESS before deploy.
Max event or batch size is 1 MB (Standard and above); 256 KB on Basic.
UserProperties in headers are ignored for batches; put them inside each batch item.
Suggested branches: feat/rest-api-route-azure-event-hubs, feat/docs-rest-api-azure-event-hubs (Hugo pushes).

Quick Start

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Overview

Basic Syntax

MQTT examples

Generating a SAS token

Notes

​Overview

​Basic Syntax

​MQTT examples

​Generating a SAS token

​Notes

​Related

Overview

Basic Syntax

MQTT examples

Generating a SAS token

Notes

Related