When testing your Flutter app on an iPhone, you might encounter a common issue: the app cannot call a locally hosted API. This happens because localhost refers to the device running the app (your iPhone) rather than your computer where the API is hosted. Here's how you can resolve this issue step by step:
Configure Your Local API
To make the API accessible over your network, you need to update its settings to bind to 0.0.0.0 instead of localhost. This allows it to listen for requests from any device on the same network.
For ASP.NET Core API Users:
- Navigate to the
Properties/launchSettings.jsonfile in your project.
Locate the
applicationUrlsetting.Update it from
http://localhost:<port>tohttp://0.0.0.0:<port>Save the file and restart your API.
"profiles": {
"http": {
"commandName": "Project",
"launchBrowser": true,
"launchUrl": "swagger",
"applicationUrl": "http://localhost:5132", -> "http://0.0.0.0:5132"
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
},
"dotnetRunMessages": true
},
# ...other
}
}
Update the API URL in Your Flutter App
Your iPhone needs the computer’s local IP address to reach the API. Here’s how to update the API URL in your Flutter code:
Find Your Computer’s IP Address:
Go to Settings → Wi-Fi on your Macbook.
Tap the Details next to the connected network.
Note the IP Address listed under the network details (e.g.,
192.168.0.100).
Update Your Flutter Code:
Replace the API URL in your Flutter app with the full address, including the correct port. For example: const apiUrl = "http://192.168.0.100:5132";
Ensure the Devices Are on the Same Network: Confirm that your iPhone and computer are connected to the same Wi-Fi network.
After completing these steps, your Flutter app should successfully connect to the local API while running on an iPhone. This setup is also useful for debugging and testing mobile apps in real-world scenarios before deploying to production.
By following these instructions, you can ensure a smooth development and testing process for your Flutter project. Happy coding! 🚀