Respond with PDF from API route

How to respond with a PDF from an API route

api/pdf/index.ts

const result = await fetch("https://pdf.service", {
	headers: {
		Accept: "application/pdf"
	}
})

// Do your error handling

response.writeHead(200, {
	'Content-Type': 'application/pdf',
	'Content-Disposition': 'attachment; filename="filename.pdf"'
})

response.end(
	Buffer.from(await result.arrayBuffer())
)

This will take the incoming PDF from a service and forward the response to the User. Setting the Content-Disposition in this way will result in the PDF being downloaded. Removing attachment will serve the PDF in browser.