MQTT Code is a high-performance, developer-friendly MQTT explorer, topic visualiser, and message publisher directly integrated into Visual Studio Code. It provides a native Activity Bar sidebar for broker profile and subscription management, alongside an interactive editor Webview dashboard for real-time topic tree exploration, payload inspection, and message publishing.
Key Features
Unified Broker Configuration Dialogue: Create and edit broker connections with all settings (Host, Port, Protocol, Auth, MQTT 5.0, TLS Certificates) visible in a structured, accessible editor panel with real-time Test Connection validation.
Multi-Broker Management: Save and organise multiple broker configurations (TCP, TLS/SSL, WebSocket, Secure WebSocket).
Secure Credential Storage: Passwords and private keys are encrypted using VS Code's native SecretStorage API rather than plain configuration files.
Hierarchical Live Topic Tree: Real-time aggregation of received topic paths (e.g. sensors/living-room/temperature) with message counters, retained message flags (R), and update indicators.
Multi-Format Payload Inspector: Inspect messages with automatic syntax colourisation for JSON, formatted plain text, byte dumps in Hexadecimal, and Base64.
Topic Search & Filtering: Instantly search and filter deep topic hierarchies by path or payload content.
Publishing Suite: Built-in publisher supporting QoS levels (0, 1, 2), message retention, JSON formatting, and MQTT 5.0 User Properties.
Message History Timeline: View chronological message history per topic without overwhelming system memory.
Commands & Usage
Command
Identifier
Description
Add Broker Connection
mqtt-code.add-broker
Create and save a new broker connection profile.
Connect to Broker
mqtt-code.connect-broker
Establish connection to the selected broker.
Disconnect from Broker
mqtt-code.disconnect-broker
Terminate the active broker connection.
Open Live Topic Explorer
mqtt-code.open-explorer
Open the interactive topic hierarchy and payload dashboard.
Add Topic Subscription
mqtt-code.add-subscription
Subscribe to a topic filter (e.g. # or sensors/+/temp).
Quick Publish Message
mqtt-code.quick-publish
Publish a message directly from the VS Code Command Palette.
Extension Settings
The following configuration options can be customised in your VS Code settings.json:
mqttCode.maxMessagesPerTopic: Maximum number of historical messages retained per topic in memory (default: 100).
mqttCode.autoOpenExplorerOnConnect: Automatically open the Live Topic Explorer panel when connecting to a broker (default: true).
mqttCode.defaultQoS: Default Quality of Service level for new subscriptions and publications (default: 0).
