I'm trying to use apollo RESTDataSource to wrap my rest api. I need to pass some headers to the api call.

I'm following the example from the docs:

This is my code:

  willSendRequest(request: RequestOptions) {
    console.log(`request 1: ${JSON.stringify(request)}`);
    request.headers.set('Authorization', this.context.authorization);
    console.log(`request 2: ${JSON.stringify(request)}`);
  }

I'm expecting the headers to contain 'Authorization'. But it's always empty.

The log from the above code:

request 1: {"method":"POST","path":"partnerinvoices","body":{"mand": "input","params":{},"headers":{}}
request 2: {"method":"POST","path":"partnerinvoices","body":{"mand":"input","params":{},"headers":{}}

I can override body and params in willSendRequest method without any problem.

I'm trying to use apollo RESTDataSource to wrap my rest api. I need to pass some headers to the api call.

I'm following the example from the docs: https://www.apollographql./docs/apollo-server/features/data-sources#intercepting-fetches

This is my code:

  willSendRequest(request: RequestOptions) {
    console.log(`request 1: ${JSON.stringify(request)}`);
    request.headers.set('Authorization', this.context.authorization);
    console.log(`request 2: ${JSON.stringify(request)}`);
  }

I'm expecting the headers to contain 'Authorization'. But it's always empty.

The log from the above code:

request 1: {"method":"POST","path":"partnerinvoices","body":{"mand": "input","params":{},"headers":{}}
request 2: {"method":"POST","path":"partnerinvoices","body":{"mand":"input","params":{},"headers":{}}

I can override body and params in willSendRequest method without any problem.

• javascript
• apollo-server

3 Answers 3

There are few ways that you could implement this,

within your Datasources class that extends RESTDataSource set the headers before request is being made

willSendRequest(request) {
 request.headers.set('Authorization', 'Bearer .....')
}

or as a third argument in the datasource method (post, get, put, ...)

this.post('endpoint', {}, { headers: { 'Authorization': 'Bearer ...' } })

It is super important, if you are using Typescript, that you match the original signature of the willSendRequest method:

protected willSendRequest?(request: RequestOptions): ValueOrPromise<void>;

(Link to the docs)

So, make sure the method looks like this:

    protected willSendRequest?(request: RequestOptions): ValueOrPromise<void> {
        request.headers.set("Authorization", this.context.authorization);
    }

You need to use request.headers.get('Authorization') to get your desired data. Using JSON.stringify will not give you the headers values as it is not a object literal.

willSendRequest(request: RequestOptions) {
    console.log(`request 1: ${request.headers.get('Authorization')}`);
    request.headers.set('Authorization', this.context.authorization);
    console.log(`request 2: ${request.headers.get('Authorization')}`);
  }