According to the documentation:
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?
According to the documentation:
The
initfunction 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 functionsI 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:
On starting the emulator I can see:
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:The documentation does say something about
in productionso does this mean the @init won't work locally?