export interface BlobAndHeaders { blob: Blob; headers: Headers; } myApi(arg: string): Observable<BlobAndHeaders> { return this.http.get<BlobAndHeaders>(`${this.baseURL}/api/myapi`, { observe: 'response', responseType: 'blob' as 'json', params: {arg: arg}, }).pipe(map( response => { if(response.body === null) { throw new Error('No data received'); } return {"blob": response.body, "headers": response.headers}; } )); }