UDP Server Trigger

Start a UDP server and trigger workflow when data is received

Overview

This node implements a UDP server trigger that listens for incoming UDP datagrams on a specified host and port. When data is received, it triggers the workflow with details about the message and sender. It can optionally send a response back to the client.

Common scenarios include:

Receiving sensor or IoT device data sent via UDP.
Listening for log messages or alerts broadcast over UDP.
Integrating with systems that communicate using UDP packets.

Practical example:

A network monitoring system sends status updates as UDP packets; this node captures those packets and triggers workflows to process or store the data.

Properties

Name	Meaning
Port	The UDP port number to listen on (1–65535).
Host	The IP address or hostname to bind the UDP server to. Use `127.0.0.1` for localhost or `0.0.0.0` for all interfaces.
Options	Collection of additional options:
- Encoding	Text encoding used to decode incoming UDP data. Options: UTF-8, ASCII, Base64, Hex.
- Send Response	Whether to send a response message back to the UDP client after receiving data (true/false).
- Response Message	The message text to send back if "Send Response" is enabled.
- Buffer Size	Maximum buffer size in bytes for incoming messages (64–65536).

Output

The node outputs JSON data with the following structure:

protocol: Always "udp".
server: Object containing host and port where the server is listening.
client: Object with details about the sender:
- address: IP address of the client.
- port: Client's source port.
- family: IP family (e.g., IPv4).
- size: Size of the received message in bytes.
data: The received message decoded as a string using the selected encoding.
encoding: The text encoding used.
bytes: Number of bytes received.
timestamp: ISO timestamp when the message was received.
responseSent: Boolean indicating if a response was sent back to the client.

If binary data is present, it is included under the binary field as base64 encoded data with MIME type application/octet-stream.

Dependencies

Uses Node.js built-in dgram module to create the UDP socket.
Requires no external API keys or services.
No special environment variables needed.

Troubleshooting

Port already in use error: If the configured port is occupied by another process, the node will throw an error indicating the port conflict. To resolve, choose a different port number.
UDP Server Error: Other socket errors will be reported with their message. Check network permissions and firewall settings.
No data received: Ensure the UDP client is sending data to the correct host and port matching the node configuration.
Response not received by client: Verify that "Send Response" is enabled and the response message is set correctly.