AbrechnomatBot

Telegram bot for bill splitting. Supports an unlimited amount of debtors/creditors on a bill. Calculates as little transactions as possible to pay everybody out.

Usage

• Add it to a group (works best if you give it admin privileges)
• Send /add_payment see on it should be used
• /revert_payment to remove an added payment
• Use /bill_stats to see the current amount and needed transactions
• /close_bill after all payments are done (new bill starts immediately after that)

Development Setup

• Create bot in BotFather to get the bot api token
• cp .env.example .env.local
• Fill in fields in .env.local
• Set up env variables for current session: source .env.local
• Run: iex -S mix

Deployment

• git clone https://github.com/peterhass/abrechnomat_bot.git repo
• make build && make service
• Setup database if needed: DB_CREATE=true ~/.local/share/abrechnomat_bot/bin/abrechnomat_bot start_iex
• systemctl --user start abrechnomat_bot.service

TODO

• Nadia is dead. Migrate to https://github.com/visciang/telegram ?
• Use webhooks instead of polling
• Respect edited messages?
• Create pre-filled paypal links for final payment (user needs to configure their paypal account)
• Create some way to tip bot provider (maybe after closing the bill)
• Edge-case: Users might join or leave the group while there's an open bill
• For more advanced use cases: Use telegram bot to link into a web app, authenticate with telegram oauth, leave limitations at home