MQTT GeneralInstall

Summary

Publish a JSON payload to a specified MQTT topic to perform an image search using a sample image, receiving matching regions from a Playwright-controlled browser session and optionally waiting for a response on a designated MQTT topic.

Inputs

• Topic (required) — The MQTT topic to which the image search payload is published (e.g., 'playwright/mouse/click').
• QoS — Quality of Service level for the MQTT message: 0 (at most once), 1 (at least once), or 2 (exactly once). Defaults to 1.
• Include Input Items — If enabled, includes selected fields from the input items in the payload under 'inputItems'.
• Include Input Items Fields — Specifies which fields from the input items to include in the payload if 'Include Input Items' is true.
• Wait For Response — If true, the node subscribes to a response MQTT topic and waits for a reply message before proceeding.
• Response Topic (required) — The MQTT topic to listen to for the response message if 'Wait For Response' is enabled (default is 'RES_' + Topic).
• Response Timeout (ms) — Maximum wait time in milliseconds for a response message before timing out. Defaults to 10000 ms.
• Parse Response As JSON — If true, attempts to parse the response payload as JSON. Defaults to true.
• Image Input (required) — File path or URL of the sample image used for matching within the browser viewport or full page.
• Confidence — Confidence threshold for image matching, a number between 0.01 and 1. Defaults to 0.9.
• Workflow — Name of the workflow used to isolate temporary cache files for the operation. Defaults to 'workflow'.
• Full Page — If true, the operation searches the entire page; if false, only the viewport is searched. Defaults to false.
• Max Results — Maximum number of matching image regions to return. Must be at least 1. Defaults to 20.

Output shape

a list of items passing through with added mqtt field containing the topic, action metadata, the original payload sent, and if requested, a response object received from the response topic

Outputs input items enriched with an 'mqtt' field that includes published topic/action/payload and optionally response data if 'Wait For Response' is enabled and a reply is received within the timeout period. If multiple input items are provided, each is returned with corresponding metadata. On failure, errors are thrown or returned based on node configuration.

Examples

Example 1: Publish an image search action with a sample image URL and confidence threshold, waiting for response on a designated response topic with JSON parsing enabled.

Topic set to 'playwright/image/search', QoS 1, includeInputItems false, waitForResponse true, responseTopic set to 'RES_playwright/image/search', timeout 10000ms, parse JSON true, Image Input URL 'https://example.com/target.png', confidence 0.9, workflow 'workflow', fullPage false, maxResults 20

Links

• n8n community nodes installation guide