Swift code returns 403 forbidden error when calling Yahoo Finance API via RapidAPI

Other Questions RapidAPI
1

I’m working on a personal iOS app and need to fetch stock data using the Yahoo Finance API through RapidAPI. I created a free account and obtained my API key successfully.

I copied the sample Swift code from RapidAPI’s documentation to test the connection, but I keep getting a 403 forbidden error. Other APIs work fine with similar code, so I’m confused about what’s wrong.

Here’s my current implementation:

import Foundation

let apiHeaders = [
    "x-rapidapi-host": "yahoo-finance15.p.rapidapi.com",
    "x-rapidapi-key": "my_secret_api_key_here"
]

let stockURL = "https://yahoo-finance15.p.rapidapi.com/api/yahoo/qu/quote/TSLA/financial-data?region=US&lang=en"
let urlRequest = NSMutableURLRequest(url: NSURL(string: stockURL)! as URL,
                                   cachePolicy: .useProtocolCachePolicy,
                                   timeoutInterval: 15.0)
urlRequest.httpMethod = "GET"
urlRequest.allHTTPHeaderFields = apiHeaders

let urlSession = URLSession.shared
let task = urlSession.dataTask(with: urlRequest as URLRequest) { (responseData, urlResponse, requestError) -> Void in
    if (requestError != nil) {
        print(requestError)
    } else {
        let httpResp = urlResponse as? HTTPURLResponse
        print(httpResp)
    }
}

task.resume()

The error message shows status code 403, which means the request is forbidden. I’ve double-checked my API key and it looks correct. The same endpoint works fine in RapidAPI’s web interface. Has anyone encountered this issue before? What could be causing the authentication to fail in Swift but work in the browser?

2

Happens all the time with third-party APIs. That 403 is probably rate limiting or the RapidAPI provider changed something without telling anyone.

I’ve been through this nightmare building financial dashboards. Instead of constantly fighting unreliable APIs and auth issues, I just automated the whole data pipeline.

Latenode handles the API calls, manages auth automatically, and retries when services crash. You can swap between data providers without touching your iOS code.

I built a stock data automation that pulls from multiple sources, cleans everything, and serves it through one reliable endpoint. Takes 10 minutes to setup, saves hours of debugging.

Best part? You can test everything visually before hooking it to your Swift app. No more guessing why requests fail.

3

This sounds like an SSL certificate or request header issue - iOS handles these differently than web browsers. I hit the same problem building my trading app last year. RapidAPI’s web interface does authentication differently than mobile HTTP requests. Try adding a Content-Type header even for GET requests: “content-type”: “application/json”. Test on a physical device, not the simulator - network behavior’s different. Some Yahoo Finance endpoints through RapidAPI need specific referrer headers that browsers include automatically but iOS doesn’t. Also check if your Apple Developer account has network restrictions that might block the request.

4

I encountered a similar issue recently. It turned out that I had trailing spaces in my API key that I copied from the dashboard, which caused the request to fail with a 403 error. I suggest regenerating your API key and typing it directly instead of copy-pasting. Additionally, keep in mind that some RapidAPI providers may return a 403 error when you’ve reached your rate limits, so check your usage. Lastly, verify the endpoint URL, as Yahoo Finance APIs on RapidAPI can change frequently, and the documentation may not always reflect the current endpoints.

5

check your user-agent header first. Yahoo Finance endpoints on RapidAPI will hit you with a 403 if it’s missing. add “user-agent”: “Mozilla/5.0…” to your headers dict. also double-check that your RapidAPI subscription’s still active - free tiers can expire without warning.