Local plugin giving {"code":"UNIMPLEMENTED"}

Capacitor
1

Hi, I’m developing an Angular + Capacitor app for iOS and I’m trying to use a simple native plugin (like the Echo example) by following the official Capacitor documentation: Capacitor iOS Plugin Guide | Capacitor Documentation

I did not create the plugin as a separate package using npx @capacitor/plugin generate. Instead, I created the Swift files manually and added them directly inside the iOS project in Xcode, next to AppDelegate.swift.

My plugin class EchoPlugin implements CAPPlugin and CAPBridgedPlugin, and defines the echo method properly. I also have an Echo.swift file that simply returns the value passed to it.

In AppDelegate.swift, I register the plugin manually with bridge.bridge?.registerPluginInstance(EchoPlugin()).

In the frontend, I use registerPlugin('Echo') and call the method using Echo.echo({ value: 'test' }).

However, the result I get is:

{"code":"UNIMPLEMENTED"}

There’s no output in the Xcode logs, so it seems the native method is never triggered.

Things I already checked:

  • The plugin has @objc, uses CAPBridgedPlugin, and defines pluginMethods correctly.
  • The jsName is "Echo" and matches what I use in registerPlugin on the frontend.
  • I ran npx cap sync ios and opened the Xcode project with npx cap open ios.
  • The Swift files are added to the project and are included in the App target.
  • I tried both registering the plugin manually in AppDelegate.swift, and letting Capacitor detect it automatically — neither approach worked.
  • I cleaned the build folder and recompiled the app.

My question is: what am I doing wrong? Is there something specific I need to do if I add Swift plugin files directly into the iOS project, instead of generating a separate plugin package?

Thanks in advance for any help or clarification.

2

An example for a “local plugin” is here - Building a Capacitor Plugin | Capacitor Documentation. Is that what you followed?

Please share your full code so we can take a look and help you better.

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