qwed-finance 0.1.0

Deterministic verification middleware for banking and financial AI

QWED-Finance 🏦

Deterministic verification middleware for banking and financial AI.

Part of the QWED Ecosystem - Verification Infrastructure for AI

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🎯 What is QWED-Finance?

QWED-Finance is a middleware layer that applies QWED's deterministic verification to banking and financial calculations. It ensures AI-generated financial outputs are mathematically correct before they reach production.

Key Features

Feature	Description
NPV/IRR Verification	Validate net present value and internal rate of return calculations
Loan Amortization	Verify payment schedules and interest calculations
Compound Interest	Check compound interest formulas with precision
Currency Safety	Prevent floating-point errors in money calculations
ISO 20022 Schemas	Built-in support for banking message standards

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🛡️ The Three Guards

1. Compliance Guard (Z3-Powered)

KYC/AML regulatory verification with formal boolean logic proofs.

from qwed_finance import ComplianceGuard

guard = ComplianceGuard()

# Verify AML flagging decision
result = guard.verify_aml_flag(
    amount=15000,        # Over $10k threshold
    country_code="US",
    llm_flagged=True     # LLM flagged it
)
# result.compliant = True ✅

Supports:

• AML/CTR threshold checks (BSA/FinCEN)
• KYC completion verification
• Transaction limit enforcement
• OFAC sanctions screening

2. Calendar Guard (Day Count Conventions)

Deterministic day counting for interest accrual - no date hallucinations.

from qwed_finance import CalendarGuard, DayCountConvention
from datetime import date

guard = CalendarGuard()

# Verify 30/360 day count
result = guard.verify_day_count(
    start_date=date(2026, 1, 1),
    end_date=date(2026, 7, 1),
    llm_days=180,
    convention=DayCountConvention.THIRTY_360
)
# result.verified = True ✅

Supports:

• 30/360 (Corporate bonds)
• Actual/360 (T-Bills)
• Actual/365 (UK gilts)
• Business day verification

3. Derivatives Guard (Black-Scholes)

Options pricing and margin verification using pure calculus.

from qwed_finance import DerivativesGuard, OptionType

guard = DerivativesGuard()

# Verify Black-Scholes call price
result = guard.verify_black_scholes(
    spot_price=100,
    strike_price=105,
    time_to_expiry=0.25,   # 3 months
    risk_free_rate=0.05,
    volatility=0.20,
    option_type=OptionType.CALL,
    llm_price="$3.50"
)
# result.greeks = {"delta": 0.4502, "gamma": 0.0389, ...}

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## 🚀 Quick Start

### Installation

```bash
pip install qwed-finance

Usage

from qwed_finance import FinanceVerifier

verifier = FinanceVerifier()

# Verify NPV calculation
result = verifier.verify_npv(
    cashflows=[-1000, 300, 400, 400, 300],
    rate=0.10,
    llm_output="$180.42"
)

if result.verified:
    print(f"✅ Correct: {result.computed_value}")
else:
    print(f"❌ Wrong: LLM said {result.llm_value}, actual is {result.computed_value}")

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📊 Supported Verifications

1. Time Value of Money

# Net Present Value
verifier.verify_npv(cashflows, rate, llm_output)

# Internal Rate of Return
verifier.verify_irr(cashflows, llm_output)

# Future Value
verifier.verify_fv(principal, rate, periods, llm_output)

# Present Value
verifier.verify_pv(future_value, rate, periods, llm_output)

2. Loan Calculations

# Monthly Payment
verifier.verify_monthly_payment(principal, annual_rate, months, llm_output)

# Amortization Schedule
verifier.verify_amortization_schedule(principal, rate, months, llm_schedule)

# Total Interest Paid
verifier.verify_total_interest(principal, rate, months, llm_output)

3. Interest Calculations

# Compound Interest
verifier.verify_compound_interest(
    principal=10000,
    rate=0.05,
    periods=10,
    compounding="annual",  # "monthly", "quarterly", "daily"
    llm_output="$16,288.95"
)

# Simple Interest
verifier.verify_simple_interest(principal, rate, time, llm_output)

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🏗️ Architecture

┌─────────────────────────────────────────────────┐
│              YOUR APPLICATION                    │
└─────────────────────────────────────────────────┘
                      │
                      ▼
┌─────────────────────────────────────────────────┐
│              QWED-FINANCE                        │
│  ┌─────────────┐  ┌─────────────┐               │
│  │   Finance   │  │   Banking   │               │
│  │  Verifier   │  │   Schemas   │               │
│  └─────────────┘  └─────────────┘               │
└─────────────────────────────────────────────────┘
                      │
                      ▼
┌─────────────────────────────────────────────────┐
│           QWED-VERIFICATION (Core)               │
│  ┌─────────┐  ┌─────────┐  ┌─────────┐         │
│  │  Math   │  │  Logic  │  │ Schema  │         │
│  │ (SymPy) │  │  (Z3)   │  │ (JSON)  │         │
│  └─────────┘  └─────────┘  └─────────┘         │
└─────────────────────────────────────────────────┘

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🔒 Why Deterministic?

Financial calculations must be exact. AI hallucinations in banking can cause:

• 💸 Wrong loan payments
• 📉 Incorrect investment projections
• ⚖️ Regulatory violations
• 🏦 Customer trust issues

QWED-Finance uses SymPy (symbolic math) instead of floating-point arithmetic, ensuring:

# Floating-point problem
>>> 0.1 + 0.2
0.30000000000000004

# QWED-Finance (SymPy)
>>> verifier.add_money("$0.10", "$0.20")
"$0.30"  # Exact!

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📦 Related Packages

Package	Description
qwed-verification	Core verification engine
qwed-ucp	E-commerce verification
qwed-mcp	Claude Desktop integration

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📄 License

Apache 2.0 - See LICENSE

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🤝 Contributing

Contributions welcome! Please read CONTRIBUTING.md first.

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Built with ❤️ by QWED-AI