Tax LINE Bot

A Thai-language LINE assistant for capturing receipts, tracking payments in Google Sheets, and viewing summaries.

Features

• Receipt OCR through Google Cloud Vision, with a Groq vision fallback.
• Groq parsing of receipt amounts, dates, and descriptions.
• Google Sheets customer and payment records.
• Payment history, search, yearly summaries, and PDF reports.
• LINE rich menus, experimental tax estimates, and scheduled reminders.

Quick start

Use Node.js 22.3+ (Node.js 24 LTS recommended). The PDF parser also supports Node.js 20.16+, but not Node.js 18 or 21.

git clone https://github.com/thinandyavin-tech/tax-line-bot.git
cd tax-line-bot
npm ci
Copy-Item .env.example .env

On macOS/Linux, use cp .env.example .env.

Fill in your local .env:

Variable	Purpose
LINE_CHANNEL_ACCESS_TOKEN	LINE Messaging API token
LINE_CHANNEL_SECRET	Webhook signature verification
GROQ_API_KEY	OCR fallback, receipt parsing, and chat
SPREADSHEET_ID	Destination Google spreadsheet
GOOGLE_SERVICE_ACCOUNT_KEY	Local service-account JSON file path
GOOGLE_CREDENTIALS_JSON	Alternative to a key file: service-account JSON in an environment variable
DRIVE_OWNER_EMAIL	Optional operator email to share newly created receipt root folders with
PORT	Server port, default 3000

The template uses Groq, matching the current OCR and assistant services.

Enable the Google Sheets and Drive APIs for your project, plus Cloud Vision for the primary OCR path. Share the destination spreadsheet with the service account as an editor. The app can create customer and payment tabs during use.

npm start

Open http://localhost:3000/health. A response containing "status":"ok" confirms the HTTP server is running; it does not verify external integrations.

Expose the server over HTTPS and set your LINE webhook to https://YOUR-HOST/webhook. Enable webhooks in the LINE channel.

Try it

Add the LINE account as a friend and follow the registration prompts. Select the receipt action, send a sample receipt image, and review the record in Google Sheets. Use the menus for payment history and yearly summaries.

The commands npm run setup-menu and npm run setup-menus update LINE rich menus. Review the scripts' configuration before running them.

Deployment

render.yaml installs the locked dependencies and prompts for the LINE credentials, GROQ_API_KEY, SPREADSHEET_ID, and GOOGLE_CREDENTIALS_JSON. Paste the service-account JSON into the hosting environment variable, never into the repository. If an operator needs browser access to new receipt folders, set DRIVE_OWNER_EMAIL explicitly in the service environment.

Receipt storage

New uploads inherit their parent folder's permissions. The bot does not grant anyone-with-the-link access or share folders with a built-in email address. A Drive URL alone does not grant access; use an authorized Google account to open it.

DRIVE_OWNER_EMAIL only affects newly created root folders. For an existing folder, review sharing in Google Drive. This update does not revoke permissions on previously uploaded files or change inherited permissions; review old receipts and parent folders before using real customer data. Customer names label folders and are not an access-control boundary.

Current limitations

• Conversation state and temporary downloads are held in memory and are lost on restart.
• /status performs live integration checks and can expose service errors. Restrict access before production use.
• OCR results and tax estimates need checking against original records.
• Evaluate with sample data. Keep credentials and customer records out of Git.

Source layout

Run npm test to exercise PDF text extraction, invalid PDFs, receipt-sharing defaults, and folder lookup with apostrophes and backslashes. Tests use the real PDF parser and mock AI/Drive requests; no credentials or network access are required.

Path	Responsibility
src/index.js	Express server and LINE webhook
src/handlers/messageHandler.js	Conversation and receipt workflows
src/services/	OCR, storage, reports, reminders, and calculations
src/setup/	Rich-menu setup and images