My Trading Bot's Silent Killer: How Forgetting to Load `.env` Across Scripts Silenced Discord Notifications

Hey everyone, it's your friendly neighborhood dev-dad here. Mid-thirties, full-time engineer by day, battling AI trading bots by night (weekends, really). Today, I want to share a subtle but potentially catastrophic bug I found in my bot. Seriously glad I caught this before deploying with real money. The symptom: Discord notifications for order fills just weren't arriving. The culprit: I forgot to load my .env variables consistently across multiple Python scripts. This is a super common pitfall when you're linking several Python scripts in a personal project, and it can be a real headache. What Happened: A "Silent Failure" Uncovered by a DRY_RUN Last weekend, I was running my usual DRY_RUN tests for my FX bot. My bot's logic is split into two main parts: planner.py , which strategizes trades, and executor.py , which actually sends orders to the exchange. The console logs looked perfectly normal. executor.py seemed to be doing its job: I saw messages like "[DRY_RUN] Order placed: ...". But the Discord notifications, which should have been firing, never appeared. At first, I thought it was a Discord outage or just a delay. But after 30 minutes, nothing. Something was definitely wrong. Thinking about what would have happened if this were real money sent shivers down my spine. "I thought I placed an order, but it never went through." "I thought I closed a position, but I was still holding it." Bugs in notification systems are terrifying because they create these silent failures. You think everything is okay, but it's not. This is precisely how real money gets lost. The Investigation: Unmasking the Culprit To narrow things down, I first tried calling notify.py (which handles all notifications) directly. It worked flawlessly; the Discord notification came through. This pointed to an issue within executor.py , which calls notify.py . I re-examined executor.py 's logs more carefully and immediately saw it: the webhook URL being passed to the notification function was None .