@o-lang/bank-account-lookup

Secure, read-only O-Lang resolver for bank account balance lookups using SQLite.

🔒 Security Features

• Read-only database access - no mutations possible
• Parameterized queries - SQL injection protected
• Sanitized output - only returns balance (no PII)
• Explicit initialization - no hidden side effects

📥 Installation

npm install @0-lang/bank-account-lookup

Initialize the database 👈 CRITICAL STEP

npx init-bank-db ./bank.db

This creates a SQLite database with sample customer

Customer 12345: $1,500 Customer 67890: $250

3. Use in your O-Lang workflow

Allow resolvers:

• bank-account-lookup

Step 1: Action bank-account-lookup "{customer_id}" Save as account_info

🔑 Why This Placement Works

1. Early visibility → Users see it in the first 5 seconds
2. Numbered steps → Clear progression (Install → Initialize → Use)
3. Highlighted as critical → Prevents the #1 user mistake (forgetting to initialize)
4. Shows output → Users know what to expect

⚠️ What Happens If You Don’t Include It

Users will:

1. Install your resolver ✅
2. Try to run their workflow ❌
3. Get this confusing error:

Error: bank-account-lookup requires "bank_db_path" in context or BANK_DB_PATH environment variable

4. Give up or open a GitHub issue

By including the npx init-bank-db command prominently, you prevent 90% of support requests.

💡 Pro Tips for README

1. Use emojis → 🛠️ npx init-bank-db ./bank.db
2. Show full workflow:

Complete example

npm install @o-lang/bank-account-lookup npx init-bank-db ./bank.db npx olang run bank-demo.ol -i customer_id=12345 -i bank_db_path=./bank.db -r @o-lang/bank-account-lookup

❓ Troubleshooting

"Command not found: init-bank-db"
→ Make sure you ran npm install first

"Database file not found"
→ Run npx init-bank-db ./bank.db to create it