Bussin: Azure Service Bus Explorer

Bussin is a client-side Azure Service Bus explorer. It runs entirely in your browser as a Progressive Web App (PWA). You can access the live version at https://bussin.dev.

Because all connections are established directly from your browser to Azure, there is no backend proxy or intermediate server transiting your credentials or messaging payloads.

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Features

• Background Operations: Run connection-safe bulk actions in the background without freezing the user interface.
• Batch Transmissions: Send high-volume message payloads using concurrent AMQP pipelining.
• Bulk Management: Resubmit or delete combinations of active and dead-letter messages with dynamic depth-locking to prevent data loss.
• Namespace Organization: Manage multiple Entra ID environments using folder nesting and text searching.
• Message Search: Search and peek messages using property and body pattern matching.

For visual walkthroughs, screenshots, and detailed guides of these features, visit the website at bussin.dev.

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Current Limitations

While Bussin supports most Azure Service Bus operations directly in the browser, there are a few limitations to keep in mind:

• Batch Send on Session-Enabled Entities: Batch sending does not currently support session-enabled queues or topic subscriptions (which require a Session ID for each message).
• Partitioned & Session-Enabled Entities: Certain administrative actions (such as the portal-based fast batch delete/purge API) are not supported by the Service Bus broker on partitioned or session-enabled entities. Bussin automatically falls back to compatible data-plane receiver flows (such as parallel receivers or sequential session loops) in these cases to complete the operation safely.

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• Direct Client-Side Architecture: Your data never leaves your browser. Bussin communicates directly with Azure APIs.
• Zero Installation: Access the tool online at https://bussin.dev or install it as a PWA.
• Entra ID Integration: Authenticate securely using your existing Azure identity and Role-Based Access Control (RBAC) roles.

Architecture and Security

Bussin operates under a 100% proxy-free, client-side security model.

When you open Bussin, your browser acts as the direct orchestrator of all network and authentication flows, bypassing intermediate relay servers or third-party databases.

graph TD
    subgraph "Browser Sandbox (100% Client-Side)"
        direction TB
        UI["Blazor WASM UI / Blades"]
        State["ExplorerViewModel & Cache"]
        MSAL["MSAL.js Authentication"]
        
        subgraph "Network Stack"
            ARMClient["ARM HTTP Client"]
            AMQPClient["Rhea AMQP-over-WebSockets"]
        end
    end

    subgraph "Azure Cloud Endpoints"
        direction TB
        AAD["Entra ID"]
        ARM["Azure Resource Manager <br> management.azure.com"]
        ASBData["Service Bus Data Plane <br> namespace.servicebus.windows.net"]
    end

    %% Authentication flows
    MSAL -.->|"1. Authenticate and Consent"| AAD
    AAD -.->|"2. Return Access Tokens"| MSAL
    
    %% ARM Resource Discovery
    UI -->|"Discover Namespaces"| State
    State -->|"3. Query Resources <br> REST + CORS"| ARMClient
    ARMClient -->|"HTTPS GET <br> Auth: Bearer ARM Token"| ARM

    %% Service Bus Data Plane Operations
    State -->|"4. Active Messaging Operations"| AMQPClient
    AMQPClient -->|"WSS Tunnel <br> Bypasses CORS"| ASBData
    AMQPClient -->|"5. CBS Handshake <br> Auth: SB Token"| ASBData

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Protocol and Connection Mechanics

1. Azure Resource Manager (ARM) Discovery: Bussin queries the Azure management API over HTTPS using standard CORS (Cross-Origin Resource Sharing) requests. This enables automatic resource discovery of subscriptions, resource groups, namespaces, queues, and topics without typing connection strings.
2. Azure Service Bus Data Plane (CORS Bypass): Standard Azure Service Bus data-plane REST endpoints lack CORS headers, which prevents standard browser HTTPS REST calls. Bussin bypasses this restriction by establishing direct AMQP 1.0 connections over secure WebSockets (wss://<namespace>.servicebus.windows.net:443/$servicebus/websocket), which do not fall under CORS restrictions.
3. Identity and Claims-Based Security: All communication is secured using your active Entra ID tokens. The client performs an AMQP Claims-Based Security (CBS) handshake with the $cbs node of the namespace directly, matching standard enterprise security policies without storing credentials.

Alternatives

Bussin serves as a cross-platform, web-native alternative to traditional desktop messaging clients:

• No Backend: Unlike other web-based explorers, Bussin has no backend. Your Service Bus connection strings or tokens are never sent to external servers.
• Clean UI: A responsive interface built with Blazor WebAssembly.
• Dev-Focused: Simple debugging for queues, topics, and subscriptions.

Permissions and Security

Bussin respects your Azure RBAC configuration. It uses two-step delegated consent:

1. Azure Management API: To list namespaces and entities.
2. Azure Service Bus: For data-plane operations (Peek, Send, etc.).

Required Roles: Azure Service Bus Data Owner, Receiver, or Sender.

Development

Requirements:

• .NET 10 SDK
• Node.js 20+

# Build client-side AMQP library
cd client-js && npm ci && npm run build

# Build Blazor WASM app
cd ../src && dotnet publish -c Release

Releases

When creating a new release of Bussin on GitHub, please ensure the release notes include a link pointing back to the official site: For more details and live usage, visit https://bussin.dev.

License

Business Source License 1.1 (BSL) - See LICENSE file for details.

• Usage of the software is always free for personal, educational, or internal business use.
• Commercial redistribution, rebranding, or hosting this software as a service (SaaS) by third parties is prohibited.

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Disclaimer: Bussin is a community tool and is not officially supported by Microsoft. Use at your own risk.

Looking for the marketing website or documentation source code? Visit sgebb/bussin-site.