To modify request or response headers, you’ll first need to make a copy of the object in order to make it mutable. You can then use the Headers interface to add, change, or remove headers.
Set a new header on your response before returning it the end user.
addEventListener('fetch', event => {
event.respondWith(handleRequest(event.request))
})
async function handleRequest(request) {
let response = await fetch(request)
// Make the headers mutable by re-constructing the Response.
response = new Response(response.body, response)
response.headers.set('x-my-header', 'custom value')
return response
}Set a new header on the request before fetching a response from the origin.
addEventListener('fetch', event => {
event.respondWith(handleRequest(event.request))
})
async function handleRequest(request) {
// Make the headers mutable by re-constructing the Request.
request = new Request(request)
request.headers.set('x-my-header', 'custom value')
return await fetch(request)
}