iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Keep a shared market-data API key on a server you control, not in browser JavaScript. Have the web app call an endpoint on your server; that endpoint authenticates with the provider and returns only the data the interface needs. CORS does not hide a key, and protecting the credential does not grant permission to show or redistribute market data.
Why a key in the browser is exposed
Anything delivered to a visitor’s browser can be inspected. A key embedded in JavaScript can be found in the downloaded code, and a key sent with a browser request can be seen in that request. Obfuscating a bundle or limiting cross-origin requests does not turn a shared secret into a secret.
MarketData.app explicitly warns against embedding its token in an unauthenticated public website and says, “Never Expose Your Token on a Public Website” in its CORS documentation. Its authentication guidance treats the bearer token as a secret, comparable to a username and password.
Use a server endpoint between the app and provider
The browser should request data from your own backend, serverless function, or backend-for-frontend route. That server checks the request, reads the provider credential from server-side configuration or a managed secret store, calls the market-data API, and sends the UI a limited response.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
- Create an app endpoint. Define a route for the specific data the interface needs, such as a quote or a bounded historical range.
- Store the key server-side. Use your deployment platform’s server-only environment configuration or secret manager. Do not use a build-system variable convention that exposes values in the browser bundle.
- Call the provider from the server. Follow the selected API’s authentication method. For MarketData.app, use its recommended bearer-token header rather than putting the token in a URL, where credentials may be stored or cached.
- Return only necessary data. Shape the response for the UI; never include the provider key in JSON, HTML, source maps, or error messages.
- Constrain and protect the route. Validate symbols, time ranges, and other inputs server-side. Apply your app’s access checks and request limits so the endpoint cannot be used as an unrestricted proxy.
- Handle failures safely. Avoid logging credentials. Return useful but non-sensitive errors, and revoke and replace a credential if it is exposed. MarketData.app says a compromised token should be revoked and reissued through its helpdesk.
The exact route design, validation rules, and limits depend on your app; they are implementation safeguards rather than a universal provider-prescribed recipe.
Choose the authentication flow for the API you actually use
Providers and products do not all authenticate the same way. Use the documentation for the precise API product and account involved; do not assume that one vendor’s header or token flow applies to another.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
| API example | Documented authentication | What to do in your app |
|---|---|---|
| MarketData.app | Bearer-token authentication; its guidance recommends header authentication rather than URL credentials. | Keep the token server-side and send it to the provider in the documented header. See MarketData.app authentication. |
| Alpaca Trading API | Credentials are sent in the APCA-API-KEY-ID and APCA-API-SECRET-KEY headers. |
Send credentials from your server using the Trading API’s documented method. See Alpaca market-data documentation. |
| Alpaca Broker API | A client-credentials exchange produces a short-lived access token. | Implement the exchange and token handling documented for the Broker API; do not substitute the Trading API’s credential pattern. |
CORS does not protect an API key
CORS controls whether browser code from one origin may read certain cross-origin responses. It does not conceal code or requests from the person using that browser, authenticate your visitors, or prevent a shared key in the page from being copied. A CORS allowlist is therefore not a substitute for keeping a shared credential on the server.
MarketData.app describes its CORS headers as a convenience for personal browser use and local development, not as protection for a public-site token. Its CORS guidance specifically warns against exposing the token on an unauthenticated public website.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Check market-data rights separately from key security
A backend proxy protects the credential; it does not decide whether your product may display, cache, export, or redistribute the data. Check the selected provider’s current terms for your audience, geography, exchange and data type, caching, public display, and downstream sharing. If the intended use is unclear, ask the provider for written licensing guidance.
MarketData.app’s CORS page states that public-facing display of its data requires a commercial redistribution license under its terms. Its separate BYOK material describes a restricted user-key model: the key stays on the user’s device and data remains within the app subject to that page’s restrictions; it is not general permission for exports or onward sharing. These are MarketData.app-specific terms and should not be generalized to other providers. See its CORS documentation and BYOK information.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
When a user-provided key is a different option
A user-key design means each user supplies and retains their own credential rather than your app distributing one shared application key. That changes who owns the credential, but it does not automatically authorize your app to export or redistribute data, nor does it remove the need to follow the provider’s key-handling rules. MarketData.app’s BYOK conditions are specific to its program; review the applicable provider terms before adopting this model.
PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchQuick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
If a key has already reached the browser
- Revoke or rotate the exposed credential with the provider; deleting it from the current source code alone does not invalidate copies already seen.
- Remove it from client code, browser-visible configuration, and responses, then move provider calls behind a server endpoint.
- Review logs and deployment artifacts for accidental disclosure, and avoid reproducing the key in support messages or error reports.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
