MQTT GeneralInstall

Summary

Publish a structured MQTT message to trigger a Developer action to capture a webpage screenshot, optionally waiting for and returning a response.

Inputs

• Topic (required) — MQTT topic to which the capture command payload is published.
• QoS — Quality of Service level for the MQTT publish (0, 1, or 2).
• Include Input Items — Whether to include data fields selected from the incoming items as part of the payload.inputs.inputItems.
• Include Input Items Fields — Comma or newline-separated list of fields from input items to include in payload.inputItems when Include Input Items is enabled.
• Wait For Response — Whether to subscribe and wait for a response message on a specified response topic before completing.
• Response Topic (required) — MQTT topic to receive the response message if waiting for response; defaults to RES_.
• Response Timeout (ms) — Maximum time in milliseconds to wait for the response message when waiting for response.
• Parse Response As JSON — Whether to parse the response payload as JSON when possible.
• Workflow — Name of the workflow used to isolate temporary cache files during capture.
• Folder — Target directory or mailbox folder path for the captured output.
• Full Page — If true, capture or search the entire page; if false, only the viewport is captured/searched.

Output shape

a list of items, each containing MQTT message details and optionally the response data if waiting for reply.

If Wait For Response is true, the node waits for a response message on the given response topic within the timeout and includes it in output; otherwise, outputs the published message details immediately. Includes original input data merged with MQTT metadata under mqtt key.

Examples

Example 1: Publish a capture command to topic 'developer/capture' capturing the full page, without waiting for a response.

Topic: 'developer/capture', Full Page: true, Wait For Response: false

Example 2: Publish a capture command and wait for a JSON response on a prefixed response topic for up to 10 seconds.

Topic: 'developer/capture', Response Topic: 'RES_developer/capture', Wait For Response: true, Response Timeout: 10000, Parse Response As JSON: true

Links

• n8n community nodes installation guide