How to fix functions/not-found in Firebase

Check the Firebase Console to confirm your function exists and is deployed.

1. Go to [Firebase Console](https://console.firebase.google.com)
2. Select your project
3. Navigate to Functions
4. Look for your function name in the list
5. Confirm it shows a green checkmark and is in a "Deployed" state

If the function is not listed, proceed to step 2.

If the function is not deployed, deploy it using the Firebase CLI:

firebase deploy --only functions

To deploy a specific function:

firebase deploy --only functions:myFunctionName

Wait for the deployment to complete. You should see output like:

✔  Deploy complete!

Check that the function name in your client code exactly matches the deployed function name.

In your functions/index.ts (backend):

export const helloWorld = functions.https.onCall((data, context) => {
  return { message: "Hello from Firebase!" };
});

In your client code:

import { getFunctions, httpsCallable } from "firebase/functions";

const functions = getFunctions();
const helloWorld = httpsCallable(functions, "helloWorld"); // Must match exactly

await helloWorld({ data: "test" });

Function names are case-sensitive.

If you are using the Firebase emulator and getting a 404 error, use the complete function URL instead of just the emulator host.

Instead of:

useFunctionsEmulator(functions, "localhost", 5001);

Use:

if (process.env.NODE_ENV === "development") {
  connectFunctionsEmulator(functions, "localhost", 5001);
}

Or use the full project-specific URL:

const helloWorld = httpsCallable(
  functions,
  "helloWorld",
  { timeout: 10000 }
);

Start the emulator with:

firebase emulators:start --only functions

Ensure the necessary APIs are enabled in your Google Cloud project:

1. Go to [Google Cloud Console](https://console.cloud.google.com)
2. Select your project
3. Navigate to APIs & Services > Enabled APIs & services
4. Search for and enable these APIs:
- Cloud Functions API
- Cloud Build API
- Cloud Logging API

If deploying functions that use Firebase Services (Messaging, Database, etc.), also enable the corresponding APIs in the Cloud Console.

If the deploy command succeeds but the function is not callable, check the build logs:

firebase functions:log

Or check the Cloud Build logs in the Google Cloud Console:

1. Go to [Google Cloud Console](https://console.cloud.google.com)
2. Navigate to Cloud Build > History
3. Look for your recent builds
4. Click on a failed build to see error details

Common build failures include:
- TypeScript compilation errors
- Missing dependencies in package.json
- Runtime errors in function initialization