@init Doesn't seem to run locally before function execution

[Bradley-McCallion]

According to the documentation:

• https://firebase.google.com/docs/reference/functions/2nd-gen/python/firebase_functions.core
• https://firebase.google.com/docs/functions/tips#recommended_use_oninit_to_defer_initialization
• https://firebase.google.com/docs/functions/config-env#init-fn

The init function can be used as a hook for cold-start initialization code - it is a way to register code that should run once, during cold start, right after the Functions Framework loads your module and before it starts handling requests.

From some local testing however, I can't get this function to run. When I spin up the emulator locally with firebase emulators:start --project testing --only functions I can see that the function discovery is executed but the @init function is not executed (as expected). However, after calling one of the functions I would have expected the @init function to run but it doesn't seem to.

My example code is something like this:

from firebase_functions.core import init
from firebase_admin import initialize_app

print("-----------------Main module loaded-----------------------------", flush=True)

@init
def initialize() -> None:
    print("---------------------Initializing----------------------------------", flush=True)

app = initialize_app()


from functions import *

On starting the emulator I can see:

 * Running on http://127.0.0.1:8083
Press CTRL+C to quit

-----------------Main module loaded-----------------------------

127.0.0.1 - - [19/Sep/2025 10:26:15] "GET /__/functions.yaml HTTP/1.1" 200 -

127.0.0.1 - - [19/Sep/2025 10:26:15] "GET /__/quitquitquit HTTP/1.1" 200 -

Terminated

✔  functions: Loaded functions definitions from source: contact_us.

Confirming that the main module gets called. But after executing a function I would have expected to see debug line within the initialize() statement. However, after executing all I see is:

i  functions: Loaded environment variables from .env, .env.demo-abcd.
>  -----------------Main module loaded-----------------------------
>   * Serving Flask app 'contact_us'
>   * Debug mode: on
>  WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
>   * Running on http://127.0.0.1:8825
>  Press CTRL+C to quit
>   * Restarting with watchdog (inotify)
>  -----------------Main module loaded-----------------------------
>   * Debugger is active!
>   * Debugger PIN: 136-720-496
>  127.0.0.1 - - [19/Sep/2025 10:26:33] "GET /__/health HTTP/1.1" 400 -
i  functions: Beginning execution of "europe-west2-contact_us"
>  127.0.0.1 - - [19/Sep/2025 10:26:33] "POST / HTTP/1.1" 200 -
i  functions: Finished "europe-west2-contact_us" in 621.762172ms

The documentation does say something about in production so does this mean the @init won't work locally?

[CorieW]

Hi! Thanks for raising this. It's been received and we will provide updates when available.