What is The Error Code?

Received an error like:

Code=1590 \"The operation couldn't be completed. (Cocoa error 1590.)

And you have no clue what the code means? Use this app to find a description:

Supported error domains

  • NSCocoaErrorDomain
  • NSURLErrorDomain
  • kCFErrorDomainCFNetwork

Can I help contribute?

Yes, please! Feel free to open a PR and add new error descriptions to this JSON file.

Using ChatGPT to generate JSON

ChatGPT has been a great help in creating JSON output from header files like this one. I’ve used the following prompt:

Create a JSON array of the following input and use property names key, code, and description: 
NSPersistentStoreTimeoutError                    = 134090, // failed to connect to the persistent store within the specified timeout (see NSPersistentStoreTimeoutOption)
NSPersistentStoreUnsupportedRequestTypeError	 = 134091, // an NSPersistentStore subclass was passed an NSPersistentStoreRequest that it did not understand

I just want to use the app and keep it up to date with the latest errors

Download RocketSim and use it from the Menu Bar. (Coming in version 10.1)


This library is created by Antoine van der Lee after getting enough likes.


WhatTheErrorCode is available under the MIT license. See the LICENSE file for more info.


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