The Document node sends a document to the chatbot from a local file or from a URL or from a Buffer passed by an upstream node (the simplest way to use it to chain with to File node or a Http node).

Some file types are not supported by a specific platform, for example Telegram only supports .zip, .pdf, .gif. If a file not supported is automatically compressed and converted in a ZIP file.

To programmatically send a document, in the upstream Function node

msg.payload.document = '/my-file.pdf';
return msg;

Or using a Buffer:

msg.payload.document = new Buffer(<my-buffer>);
msg.payload.filename = 'my-file-name.pdf';
return msg;

In case the upstream node pass through a Buffer, the node tries to extract a proper file name (visible to user in the chat client) using the payload of the upstream File node or the name of the node itself.

Available parameters for the msg.payload