Fetch error on Office Script (Does Bearer Authorization token for external calls work in Excel script?)

Question

Hi all, I am trying to run the following script for an external API call with a Bearer Token:

export interface DATOS {
    count: number;
    results: Result[];
    skill_memberships: SkillMemberships;
    meta: Meta;
}
export interface Meta {
    count: number;
    page_count: number;
    page_number: number;
    page_size: number;
}
export interface Result {
    key: string;
    id: string;
}
export interface SkillMemberships {
    "87530265": The87530265;
}
export interface The87530265 {
    level: number;
    max_level: number;
    created_at: string;
    updated_at: string;
    cached_skill_name: string;
    skill_id: string;
    creator_id: string;
    user_id: string;
    id: string;
}
export interface TESTBASIC {
    userId: number;
    id: number;
    title: string;
    body: string;
}
async function main(workbook: ExcelScript.Workbook): Promise<void>
{
    var myHeaders = new Headers();
    myHeaders.append("Authorization", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
    console.log("Test2");
    let url = encodeURI('https://api.xxxxxxxxxxxx.com/');
    try
    {
        let fetchResult = await fetch(url, {
            method: 'GET',
            headers: {                
                "Access-Token": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
                "Content-Type": "application/json",
                "Accept": "application/json"
            },
            redirect: 'follow'
        });
        let json: DATOS = await fetchResult.json();
        console.log(json);
    } catch(e)
    {
        console.log(e);
    }
}

But every time I try to run it to show me the result in the console, I always get the following error:

{message: "Failed to fetch", name: "TypeError", stack: "TypeError: Failed to fetch at 
self.fetch (https://c0a4c0b1-8f01-4eaa-84f0-6434f1eb8473.officescripts.microsoftusercontent.com/eed0a086-3498-4f91-a377-1e0265ecc0cc/worker.js:99:13) 
at main (blob:https://c0a4c0b1-8f01-4eaa-84f0-6434f1eb8473.officescripts.microsoftusercontent.com/5db7939c-4ae9-4802-8c9f-aed101943d56:183:45) 
at async _____wrapperMain (blob:https://c0a4c0b1-8f01-4eaa-84f0-6434f1eb8473.officescripts.microsoftusercontent.com/5db7939c-4ae9-4802-8c9f-aed101943d56:209:20)"}

One of the doubts that I have regarding this script is if Excel Office Script is directly capable of working with this type of tokens, because perhaps if it cannot work with this type of tokens, this type of error will always appear, is this true? ? Or maybe this is due to an error in the text structure or interfaces? Is there a way to do this via Office Script, or would it only be possible to do it via VBA?

Regards

Answer 1

Fetch calls to external APIs (no matter requiring bearer auth headers or not) should work in Office Scripts as long as:

• The API you are calling into allow CORS.
• There is no tenant/site/organization policy that protects the workbook or blocks external API calls. You can find more information here: https://learn.microsoft.com/en-us/office/dev/scripts/develop/external-calls.

For troubleshooting, you can also open the browser's developer tools panel (press F12) and keep an eye on the Network tab and see if there are any errors from that fetch API request while running your script. Sometimes you can also take a look at the Console tab to see if there is anything unexpected.

Also I noticed you declared a myHeaders variable with a header named Authorization. But in the actual fetch call, you used another header named Access-Token. Is that intentional?