Setting custom headers for individual requests

I’d like to set custom headers for individual requests, e.g. not when initialising ApolloClient.

I am running a query like this:

client.query({ query: /* some graphql query */});

I have tried like this:

	query: /* some graphql query */,
	contenxt: {
		headers: {
			"SomeCustomHeader": 123

But that did not work. Is there another way to do it, on the fly?

I have found this, but it does not work: Advanced HTTP networking - Apollo GraphQL Docs

@apolloinspace May I ask if you ever found a solution to this? I"m currently having the same trouble, with custom headers not being sent upstream to the GQL end-point?

Also throwing out the question to the rest of the community: I’m noticing the same thing happening, using authentication via the ApolloLink() approach from the above link about Advanced HTTP Networking.

As far as I can see, only the Authorization header gets sent upwards; my custom headers (set from the ApolloLink in the JS client) aren’t being bound to the onwards query, I think. It’s hard to tell as I don’t have access to the backend’s logging.

Now, if I use a custom dataSource, and add the headers to the request there (then call the request via a custom set of resolvers, then it works fine & the headers are apparently set). However this adds maintenance and complexity to the codebase as we’re using microservices and a lot of stitched schemas.

This is very confusing,

I created a middleware on my client in order to pass additional headers to my GraphQL instance.

// link to pass current language on every query
const middleware = new ApolloLink((operation, forward) => {
	const headers = {
		// send language requested in headers
		language: "en",
		// another header 
		clientType: "BACKEND",

	// add the authorization to the headers

	return forward(operation);

// and then in my client (i use Batch but should work with the normal one)
const httpLink = new BatchHttpLink({
	uri: "",

const client = new ApolloClient({
	link: new ApolloLink.from([middleware, httpLink]),
	cache: new InMemoryCache(), 

Actual example is here: Advanced HTTP networking - Apollo GraphQL Docs