MQTT GeneralInstall

Summary

Check if a specified image exists on the current page by publishing an MQTT message with image matching parameters and optionally wait for a response.

Inputs

• Topic (required) — MQTT topic to publish the message for checking image existence.
• QoS — Quality of Service level for MQTT publishing (0, 1, or 2).
• Include Input Items — Optionally include selected input fields from the previous node in the payload.
• Include Input Items Fields — Fields from previous input to include when 'Include Input Items' is enabled.
• Wait For Response — Whether to wait for a reply MQTT message before returning output.
• Response Topic (required) — MQTT topic to subscribe to for receiving response messages (default is RES_). Required if waiting for response.
• Response Timeout (ms) — Maximum time in milliseconds to wait for the response message.
• Parse Response As JSON — Whether to parse the response payload as JSON.
• Image Input (required) — File path or URL of the sample image used for matching the image on the current page.
• Confidence — Confidence threshold for image matching, between 0.01 and 1.
• Workflow — Workflow name used to isolate temporary cache files for this image matching operation.
• Full Page — If true, the entire page is captured/searched; otherwise, only the viewport is considered.
• Max Results — Maximum number of matching results to return.

Output shape

a list of items with MQTT request details and optionally response data

Each output item includes the original input JSON with an added 'mqtt' property containing the topic, action metadata, sent payload inputs, and if applicable, a response property with topic, raw message, and parsed payload. If 'Wait For Response' is enabled, output includes the response; otherwise, only request details are included.

Links

• n8n community nodes installation guide