Update

Author: spelluru

articles/event-grid/mqtt-how-to-http-publish.md

@@ -15,9 +15,12 @@ ms.custom:
   - ai-gen-description
 ---
 
-# How to Publish MQTT Messages via HTTP with Azure Event Grid
+# How to Publish MQTT Messages via HTTP with Azure Event Grid (preview)
 Azure Event Grid now supports publishing MQTT messages via HTTP, enabling backend systems to send messages to devices without maintaining persistent MQTT connections. This approach simplifies integration for applications that prefer stateless communication, uses secure authentication with Entra ID, and provides scalable, reliable delivery to MQTT clients. In this article, you learn how to use the HTTP Publish API, obtain the necessary credentials, and verify message delivery using popular tools like Bruno, and MQTTX.
 
+> [!NOTE]
+> This feature is currently in preview. 
+
 This article explains how to publish MQTT messages via HTTP with Azure Event Grid. 
 
 ## Get Your Connection Details
@@ -35,7 +38,7 @@ az account get-access-token --resource=https://<namespaceFQDN> --query accessTok
 
 Save this token to use in the `Authorization: Bearer <TOKEN>` header. 
 
-# [cURL](#tab/curl)
+### [cURL](#tab/curl)
 
 Here’s an example cURL command to simulate the HTTP Publish. 
 
@@ -57,7 +60,7 @@ In this sample command:
 - Add optional headers for QoS, retain flag, response topic, user properties. 
 - Payload goes in the request body. 
 
-# [Bruno](#tab/brno)
+### [Bruno](#tab/brno)
 
 ## Import to Bruno
 1. Open Bruno.

articles/event-grid/mqtt-http-publish.md

@@ -1,5 +1,5 @@
 ---
-title: Publish MQTT Messages via HTTP with Azure Event Grid
+title: HTTP Publish of MQTT messages with Azure Event Grid
 description: Publish MQTT messages via HTTP with Azure Event Grid for scalable server-to-device communication. Learn how to use the HTTP Publish API effectively.
 #customer intent: As a backend developer, I want to publish MQTT messages via HTTP so that I can integrate with Azure Event Grid without maintaining persistent MQTT sessions.  
 author: spelluru
@@ -15,31 +15,34 @@ ms.custom:
   - ai-gen-description
 ---
 
-# Overview
+# HTTP Publish of MQTT messages with Azure Event Grid (preview)
 
 The Azure Event Grid MQTT Broker HTTP Publish API empowers customers to publish MQTT messages using standard HTTP requests. This complements direct MQTT client connections, providing a simple and scalable option for server-side systems that prefer HTTP for server-to-device command-and-control, updates, or retained message management.
 
+> [!NOTE]
+> This feature is currently in preview. 
+
 Key benefits:
 
 - Allows backend services to send MQTT messages without keeping persistent MQTT sessions open.
 - Helps protect broker stability by limiting per-client MQTT sessions.
 - Ensures consistent message processing for both MQTT and HTTP-originated messages.
 
-# When to Use HTTP Publish
+## When to Use HTTP Publish
 
 Consider HTTP Publish when:
 
 - Your backend services are HTTP-native and need to send device commands or updates over MQTT.
 - You want to manage retained messages without opening an MQTT connection.
 - You need to scale up publish capacity without exhausting session limits.
 
-# How It Works
+## How It Works
 
 1. HTTP clients issue an HTTP POST request with MQTT publish details.
 1. Event Grid maps HTTP request parts to standard MQTT PUBLISH packet properties.
 1. Messages flow through the Event Grid routing and enrichment pipeline, ensuring delivery guarantees and applying any enrichment or transformation.
 
-# Example: MQTT PUBLISH Equivalent
+## Example: MQTT PUBLISH Equivalent
 
 ```http
 PUBLISH Topic Name: devices/CXa-23112/prompt  
@@ -52,7 +55,7 @@ User Property: RequestId = 55f4a7ee-b0b4-4d7f-8eb5-2edba2ced5d7
 Payload: Please accept terms of licensing and agreement
 ```
 
-# Example: HTTP Publish Request
+## Example: HTTP Publish Request
 
 ```http
 POST /mqtt/messages?topic=devices%2FCXa-23112%2Fprompt&api-version=2025-02-15-preview HTTP/1.1  
@@ -72,7 +75,7 @@ Please accept terms of licensing and agreement
 
 
 
-# Request Parameters
+## Request Parameters
 
 This table describes how HTTP request parts map to MQTT PUBLISH packet properties. Refer to the original documentation for full details.
 
@@ -95,7 +98,7 @@ This table describes how HTTP request parts map to MQTT PUBLISH packet propertie
 - Percent-encoding is required for topic and response topic.
 - Correlation Data must be base64-encoded.
 
-# High-level steps for using HTTP Publish
+## High-level steps for using HTTP Publish
 
 - Step 1: Prepare your Entra ID bearer token for authentication.
 - Step 2: Construct your HTTP POST request to your Event Grid MQTT broker endpoint.
@@ -105,14 +108,14 @@ This table describes how HTTP request parts map to MQTT PUBLISH packet propertie
 - Step 6: Send the request.
 - Step 7: Confirm delivery via logs and metrics in the Event Grid portal.
 
-# Authentication & Authorization
+## Authentication & Authorization
 
-- HTTP Publish uses Azure Entra ID for authentication.
+- HTTP Publish uses Microsoft Entra ID for authentication.
 - Add a Bearer token to the Authorization header.
-- The Entra Object ID becomes the MQTT clientId.
+- The Microsoft Entra Object ID becomes the MQTT clientId.
 - The AuthN/AuthZ model aligns with standard MQTT connections.
 
-# Routing, Enrichment & Observability
+## Routing, Enrichment & Observability
 
 - HTTP messages pass through the Event Grid routing pipeline, ensuring consistent routing, enrichment, and delivery guarantees.
 
@@ -123,148 +126,15 @@ This table describes how HTTP request parts map to MQTT PUBLISH packet propertie
   - Source IP
   - Auth principal
 
-# Best Practices
+## Best Practices
 
 - Use lowercase header keys where possible. HTTP/2 header keys are case-insensitive.
 - Monitor throughput — HTTP messages tend to be larger than direct MQTT messages.
 - HTTP Publish shares throughput limits with direct MQTT publishes.
 
-# Throttling
+## Throttling
 
 Be aware that HTTP Publish counts towards your overall MQTT throughput quota. Monitor your usage to avoid exceeding limits.
 
-
-## How to use the HTTP Publish feature
-
-### Step 1: Get Your Connection Details
-
-- Namespace fully qualified doamin name (FQDN). Example: `contoso.westus3-1.ts.eventgrid.azure.net`.
-- Topic. Example: `devices/CXa-23112/prompt`.
-- Entra ID client credentials.
-
-### Step 2: Get a bearer token
-Run the following Azure CLI command to get a bearer token. 
-
-```bash
-az account get-access-token --resource=https://<namespace> --query accessToken -o tsv
-```
-
-### Step 3: Import to Postman or Bruno
-Use steps from the Postman (or) Bruno section, depending on the tool you are comfortable with.  
-
-#### Postman
-
-1. Open Postman.
-2. Select **Import** → select `EventGrid_HTTP_Publish_Postman_Collection.json`.
-3. Go to **Variables** tab:
-   - Replace `{{namespace}}` with your namespace FQDN.
-   - Replace `{{topic}}` with your MQTT topic.
-   - Replace `{{entra_token}}` with your token from Step 2.
-4. Select **Send**. You should get 202 or 204.
-
-#### Bruno
-
-1. Open Bruno.
-2. Select **Import Collection**, and then select `EventGrid_HTTP_Publish_Postman_Collection.json`.
-3. Go to **Variables** tab:
-   - Replace `{{namespace}}` with your namespace FQDN.
-   - Replace `{{topic}}` with your MQTT topic.
-   - Replace `{{entra_token}}` with your token from Step 2.
-
-### Step 4: Verify in MQTTX
-
-- Open MQTTX, connect using your broker’s endpoint, TLS, and your normal MQTT auth.
-- Subscribe to the topic you used in the HTTP POST.
-- You should see your payload appear.
-
-### Troubleshooting
-
-- **401 Unauthorized?** — Refresh your token.
-- **403 Forbidden?** — Check your topic or permissions.
-- **Message doesn’t appear?** — Ensure topic is percent-encoded in the URL, check broker routing config, and verify you’re using the same namespace.
-
-
-# Tutorials:
-
-## Option 1: Using cURL Command
-
-### Step 1: Get Your Connection Details
-
-- **Event Grid Namespace**: e.g., contoso.westus3-1.ts.eventgrid.azure.net
-- **Topic**: e.g., devices/CXa-23112/prompt
-- **Entra Client ID** and Tenant: for getting your bearer token.
-- **Audience (Resource)**: your Event Grid Namespace URL.
-
-### Step 2: Get an Entra ID Token
-
-Use **Azure CLI** or your preferred flow to get a token:
-
-```bash
-az account get-access-token \
-  --resource=https://contoso.westus3-1.ts.eventgrid.azure.net \
-  --query accessToken \
-  -o tsv
-```
-
-Save this token to use in the Authorization: Bearer `<TOKEN>` header.
-
-### Step 3: Prepare Your HTTP POST Request
-
-Here’s an example using curl to simulate the HTTP Publish.
-
-```bash
-curl -X POST "https://contoso.westus3-1.ts.eventgrid.azure.net/mqtt/messages?topic=devices%2FCXa-23112%2Fprompt&api-version=2025-02-15-preview" \
-  -H "Authorization: Bearer <ENTRA_TOKEN_HERE>" \
-  -H "mqtt-qos: 1" \
-  -H "mqtt-retain: 0" \
-  -H "mqtt-response-topic: devices%2FCXa-23112%2Freply" \
-  -H "mqtt-correlation-data: PlXCscK2wrbCuy8=" \
-  -H "mqtt-user-properties: W3siVXJnZW5jeSI6ImFsZXJ0In0seyJSZXF1ZXN0SWQiOiI1NWY0YTdlZS1iMGI0LTRkN2YtOGViNS0yZWRiYTJjZWQ1ZDcifV0=" \
-  -H "Content-Type: text/plain;charset=UTF-8" \
-  --data-raw "Please accept terms of licensing and agreement"
-```
-
-### Step 4: Verify Publish with MQTT Client
-
-Use **MQTTX** or any MQTT library (like paho-mqtt Python) to subscribe to the same topic to confirm delivery.
-
-#### Example MQTTX Steps
-
-1. Create a new connection in MQTTX:
-   - Host: contoso.westus3-1.ts.eventgrid.azure.net
-   - Port: 8883 (TLS)
-   - Client ID: same as your Entra Object ID.
-   - Username/Password: N/A — use certificate or token auth if configured.
-2. Subscribe to devices/CXa-23112/prompt.
-3. Run the HTTP Publish and watch for the message in MQTTX.
-
-### Step 5: Validate Success
-
-- If the publish succeeds, you’ll see:
-  - **HTTP Response**: 204 No Content or 202 Accepted (depending on routing rules).
-  - MQTT client sees the message instantly.
-
-#### Expected log in your MQTT client
-
-```text
-Topic: devices/CXa-23112/prompt
-Payload: Please accept terms of licensing and agreement
-QoS: 1
-```
-
-### Step 6: Handle Failures
-
-- If the token is missing or expired: You’ll get 401 Unauthorized.
-- If the topic is invalid or you don’t have rights: 403 Forbidden.
-- If routing fails internally: 500 Internal Server Error with diagnostic info.
-
-💡 Check logs in Event Grid Metrics and Diagnostic Logs for delivery status.
-
-## Option 2: Using Postman or Bruno
-
-This helps you test the HTTP Publish feature using:
-
-- Postman or Bruno collection (provided).
-- MQTTX or your MQTT client to verify delivery.
-- Entra ID for secure auth.
-
+## Next step
+See [How to publish MQTT messages using HTTP with Azure Event Grid](mqtt-how-to-http-publish.md).

articles/event-grid/mqtt-overview.md

@@ -123,7 +123,7 @@ An MQTT retain message is used to store the last known good value of a topic on
 
 ### HTTP Publish(preview) 
 
-HTTP Publish enables applications to publish MQTT messages to Azure Event Grid MQTT Broker over a simple HTTPS POST request, without maintaining an active MQTT session. It’s best suited for scenarios where MQTT clients are not feasible or necessary—such as serverless functions, cloud services, or backend applications—allowing event-driven architectures to inject MQTT messages reliably and securely. Common use cases include publishing device commands, alerts, or control signals from Azure Functions, Logic Apps, or API integrations. 
+HTTP Publish enables applications to publish MQTT messages to Azure Event Grid MQTT Broker over a simple HTTPS POST request, without maintaining an active MQTT session. It’s best suited for scenarios where MQTT clients are not feasible or necessary—such as serverless functions, cloud services, or backend applications—allowing event-driven architectures to inject MQTT messages reliably and securely. Common use cases include publishing device commands, alerts, or control signals from Azure Functions, Logic Apps, or API integrations. For more information, see [HTTP Publish of MQTT messages in Azure Event Grid](mqtt-http-publish.md).
 
 ## Concepts
 See the following articles for concepts of MQTT broker in Azure Event Grid: 

articles/event-grid/mqtt-retain.md

@@ -11,7 +11,7 @@ ms.custom:
   - ai-gen-description
 ---
 
-## MQTT retain support in Azure Event Grid (preview)
+# MQTT retain support in Azure Event Grid (preview)
 The MQTT Retain feature in Azure Event Grid (Preview) ensures that the last known good value of a topic is stored and readily available for new subscribers. This capability allows new clients to instantly receive the most recent message upon connection, eliminating the need to wait for the next publish. It is beneficial in scenarios such as device state reporting, control signals, or configuration data, where timely access to the latest message is critical. 
 
 This article provides an overview of how the MQTT Retain feature works, its billing implications, storage limits, message deletion methods, and retain management considerations.

articles/event-grid/overview.md

@@ -56,7 +56,7 @@ Here are some highlights of MQTT messaging support in Azure Event Grid:
 - MQTT over WebSockets - Enable connectivity for clients in firewall-restricted environments.
 - Custom domain names - Allows users to assign their own domain names to Event Grid namespace's MQTT endpoints, enhancing security and simplifying client configuration.
 - Client Life Cycle events - Allow applications to react to events about the client connection status or the client resource operations.
-- **HTTP Publish** - Enables devices and services to send MQTT messages to Azure Event Grid over HTTPS, simplifying integration with non-MQTT clients. 
+- [HTTP Publish](mqtt-http-publish.md) - Enables devices and services to send MQTT messages to Azure Event Grid over HTTPS, simplifying integration with non-MQTT clients. 
 - [MQTT Retain](mqtt-retain.md) - Ensures the last known message on a topic is automatically delivered to new subscribers, enabling instant state synchronization. 
 
 For more information about MQTT broker, see the following articles: 

articles/event-grid/whats-new.md

@@ -16,12 +16,13 @@ The following features of Event Grid Namespaces moved from public preview to gen
 
 - [OAuth 2.0 (JSON Web Token) authentication ( Refresh- with Direct upload of (Privacy-Enhanced Mail) PEM certificates)](authenticate-with-namespaces-using-json-web-tokens.md#configure-oauth-20-jwt-authentication-settings-on-your-event-grid-namespace---direct-upload) 
 - [Custom Webhook Authentication](authenticate-with-namespaces-using-webhook-authentication.md) 
-- [MQTT Compliance – Supports assigned client identifier](mqtt-support.md#assigned-client-identifiers-preview).
+- [MQTT Compliance – Supports assigned client identifier](mqtt-support.md#assigned-client-identifiers).
 - [MQTT limit change](quotas-limits.md) – Inbound MQTT publishing requests per session: 1,000 messages per second.
 
 The following features are released in Preview: 
 - MQTT Compliance – [MQTT Retain support](mqtt-retain.md).
-- HTTP Publish capability.
+- [HTTP Publish of MQTT messages in Azure Event Grid](mqtt-http-publish.md).
+
 
 ## May 2025
 The following features of Event Grid Namespaces moved from public preview to general availability (GA).
@@ -49,7 +50,7 @@ The following features are released in Preview:
 - [OAuth 2.0 (JSON Web Token) authentication ( Refresh- with Direct upload of (Privacy-Enhanced Mail) PEM certificates)](authenticate-with-namespaces-using-json-web-tokens.md#configure-oauth-20-jwt-authentication-settings-on-your-event-grid-namespace---direct-upload) 
 - [Custom Webhook Authentication](authenticate-with-namespaces-using-webhook-authentication.md)
 - [Send MQTT events directly to Microsoft Fabric using Azure Event Grid ](mqtt-events-fabric.md)
-- MQTT Compliance –  [Supports assigned client identifier](mqtt-support.md#assigned-client-identifiers-preview). 
+- MQTT Compliance –  [Supports assigned client identifier](mqtt-support.md#assigned-client-identifiers). 
 - [MQTT limit change](quotas-limits.md) – Inbound MQTT publishing requests per session: 1,000 messages per second. 
 
 ## November 2024