CurrencyNotification

Monitors AUD/CNY and GBP/CNY exchange rates and sends a Telegram alert when the current price moves into historically extreme territory (top or bottom of the last 3 years of monthly averages).

How it works

1. Fetches 3 years of daily price history for each currency pair via yfinance.
2. Calculates the average closing price for every calendar month and sorts those values.
3. Compares today's price against the sorted monthly averages:
   • Price ≥ all-time monthly max → ALERT (consider selling)
   • Price ≥ 3rd-highest monthly avg → NOTICE (upper range)
   • Price ≤ all-time monthly min → ALERT (consider buying)
   • Price ≤ 3rd-lowest monthly avg → NOTICE (lower range)
4. Sends any triggered message to a Telegram chat, then exits.

Requirements

• Python 3.10+
• A Telegram bot token and chat ID (see setup below)

Setup

1. Clone and enter the repo

git clone https://github.com/your-user/CurrencyNotification.git
cd CurrencyNotification

2. Create and activate a virtual environment

python -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate

3. Install dependencies

pip install -r requirements.txt

4. Configure credentials

Copy the example env file and fill in your Telegram details:

cp .env.example .env

Edit .env:

TELEGRAM_TOKEN=123456789:ABCDefGhIJKlmNoPQRsTUVwxyZ
TELEGRAM_CHAT_ID=987654321

• TELEGRAM_TOKEN – get this from @BotFather after creating a bot.
• TELEGRAM_CHAT_ID – your personal or group chat ID. You can retrieve it by messaging @userinfobot.

If .env is missing or the values are empty the script still runs and prints alerts to stdout instead of sending them.

Usage

python main.py

Example output:

CurrencyNotification starting ...

Checking AUD2CNY (AUDCNY=X) ...
  Current price       : 4.7123
  Historical max avg  : 5.1042
  3rd-highest avg     : 4.9876
  Historical min avg  : 4.3201
  3rd-lowest avg      : 4.4512
  No alert: price is within the normal historical range.

Checking GBP2CNY (GBPCNY=X) ...
  Current price       : 9.2340
  Historical max avg  : 9.1800
  ...
  [Telegram sent] [GBP2CNY] ALERT: price 9.2340 >= historical MAX monthly avg 9.1800. Consider selling.

All checks complete. Exiting.

Adding more currency pairs

Open main.py and add entries to the CURRENCIES dict. The keys are display names and the values are Yahoo Finance ticker symbols:

CURRENCIES: dict[str, str] = {
    "AUD2CNY": "AUDCNY=X",
    "GBP2CNY": "GBPCNY=X",
    "EUR2CNY": "EURCNY=X",   # example addition
}

Deploying to Railway (recommended)

Railway runs the script on a schedule with no server to manage. The repo already includes a railway.toml that runs the check at 09:00 UTC, Monday through Thursday.

Steps

1. Push this repo to GitHub.

2. Go to railway.com → New Project → Deploy from GitHub repo → select this repo.

3. Once the service is created, open its Variables tab and add:

   Key	Value
   TELEGRAM_TOKEN	your bot token
   TELEGRAM_CHAT_ID	your chat ID

4. Railway will detect railway.toml automatically. The service type will be Cron and it will run python main.py every day at 09:00 UTC.

To change the schedule, edit cronSchedule in railway.toml using standard cron syntax — for example "0 1 * * 1-4" for 01:00 UTC Monday–Thursday.

The script calls sys.exit(0) when finished, which is required for Railway cron jobs to register a successful run.

Automating locally with cron

If you prefer to run it on your own machine instead:

crontab -e

Add:

0 9 * * * /path/to/.venv/bin/python /path/to/CurrencyNotification/main.py