💸 QWED-Tax

The Verification Gate for AI-Generated Tax Decisions

Tax software answers: "What is the correct calculation?"

QWED-Tax answers: "Should this AI-generated tax decision be allowed to execute?"

QWED-Tax sits between AI agents and execution systems (Gusto, Avalara, Stripe) — verifying that tax decisions are legally sound before they execute. Not a calculator. Not a filing platform. A deterministic verification layer powered by Z3 and Decimal math.

⚔️ Why QWED-Tax?

Unlike calculators (Avalara) or executors (Gusto), QWED is a Verifier. We sit between the AI and the Execution.

🚨 The Problem: Unverified AI Tax Decisions

AI agents are making payroll and tax decisions that execute unchecked — misclassifying workers, miscalculating withholding, and filing incorrect returns.

QWED-Tax is the verification gate:

AI-generated tax decision
        ↓
Deterministic verification (Allow / Block / Unverifiable)
        ↓
Execution system (Gusto, Avalara, Stripe)

"Death, Taxes, and Deterministic Verification."

🏗️ Architecture: The "Swiss Cheese" Defense

graph TD
    A["🤖 AI Agent"] -->|"Intent"| B{"🛡️ QWED-Tax Pre-Flight"}
    
    subgraph "Deterministic Guards"
    C["Personal Tax<br/>(Payroll, 1099 vs W2)"]
    D["Trading Tax<br/>(F&O, Crypto, STCG)"]
    E["Corporate Tax<br/>(Sec 185 Loans, Valuations)"]
    end
    
    B --> C & D & E
    C & D & E -->|"Audit Result"| B
    
    B -- "✅ Verified" --> F["🚀 Fintech API (Avalara/Gusto)"]
    B -- "🛑 Blocked" --> G["🚫 Stop & Throw Error"]
    
    style B fill:#00C853,stroke:#333,stroke-width:2px,color:white
    style G fill:#ff4444,stroke:#333,stroke-width:2px,color:white

🧠 Procedural Accuracy (MSLR Aligned)

Unlike standard calculators, qwed-tax verifies the procedure, not just the result. This aligns with Multi-Step Legal Reasoning (MSLR) to prevent "Right Answer, Wrong Logic" errors.

• Step 1: Sanction Check $\rightarrow$ Is this transaction legal? (e.g., RelatedPartyGuard blocks illegal loans before rate checks).
• Step 2: Limit Check $\rightarrow$ Is it within quota? (e.g., RemittanceGuard checks LRS limit before TCS).
• Step 3: Calculation $\rightarrow$ Apply math.

📊 Real World Failures We Blocked (From Audit Logs)

💡 Verification Coverage

Deterministic Tax Verification Layer for AI Agents A verification layer for tax decisions supported by z3-solver and python-decimal. It verifies claims across multiple jurisdictions — it does not calculate, file, or execute.

Note: Guards verify specific deterministic rules. Full tax compliance (GSTR filing, GSTN integration, HSN/SAC classification) is explicitly out of scope. See What QWED-Tax Is Not.

🚫 What QWED-Tax Is Not

QWED-Tax verifies decisions. It does not originate them, file them, or maintain the data pipelines that compliance platforms require.

Explicitly out of scope:

• GSTN portal integration / live GSTIN status lookup — QWED validates GSTIN format and checksum, not registration status
• GSTR-1 / GSTR-2B / GSTR-3B reconciliation — filing workflows belong in a compliance platform
• e-Invoicing / IRN generation — execution-side operations, not verification
• HSN/SAC classification — corpus maintenance is a data-curation problem, not a verification problem
• Tax filing or return preparation — QWED verifies claims; it does not originate filings
• Regulatory change tracking as a service — notifications, circulars, per-state rate updates
• Payroll processing or execution — QWED verifies payroll math; it does not run payroll
• Tax calculation as a standalone engine — QWED verifies a claimed result against statutory rules; it does not compute taxes for filing

If a feature requires live data sync, classification-corpus maintenance, or filing workflows, it belongs in a compliance platform — not in QWED-Tax.

🛡️ The Guards

🇺🇸 United States (IRS)

1. PayrollGuard: Verifies Gross-to-Net logic and enforces 2025 FICA Limit ($176,100).
2. ClassificationGuard (IRS Common Law): Uses deterministic rules to verify W-2 vs 1099 status.
3. ReciprocityGuard: Deterministically verifies state tax withholding (NY vs NJ rules).
4. NexusGuard: Verifies Economic Nexus thresholds ($100k/$500k sales) to catch missing tax liabilities.

🇮🇳 India (CBDT / CBIC / FEMA)

1. CryptoTaxGuard: Enforces Section 115BBH (No set-off of VDA losses).
2. InvestmentGuard: Distinguishes Intraday (Speculative) from Delivery (Capital Gains) using strict rules.
3. GSTGuard:
   • Reverse Charge Mechanism (RCM): Verifies liability for notified services — GTA, Legal, Security, Director, Sponsorship, Renting of motor vehicle, and Import of service.
   • CGST/SGST/IGST split: Verifies the tax breakup against the place of supply (intra-state vs inter-state).
4. RemittanceGuard (FEMA):
   • LRS Limit: Enforces $250,000 annual limit per PAN.
   • Prohibited: Blocks Gambling, Lottery, and Racing remittances.
   • TCS: Applies 20% Tax Collected at Source on generic investments/tours.
5. Accounts Payable Guards:
   • InputCreditGuard: Blocks ITC on 'Blocked List' (Sec 17(5)) like Food/Motor Vehicles.
   • TDSGuard: Enforces withholding tax (1% vs 10%) on Contractor/Professional payments.

🔒 Zero-Data Leakage

Unlike cloud APIs (Avalara/Vertex), qwed-tax runs 100% Locally.

• Privacy First: Your payroll/trading data never leaves your server.
• No API Latency: Checks are instant (microseconds).
• GDPR/DPDP Compliant: Ideal for sensitive Fintech environments.

📖 See Determinism Guarantee for how QWED ensures 100% reproducible verification.

📦 Installation

pip install qwed-tax

⚡ Usage

from decimal import Decimal
from qwed_tax import PayrollGuard, TaxVerifier

# 1. US FICA Check
pg = PayrollGuard()
result = pg.verify_fica_tax(
    gross_ytd=Decimal("180000"), current_gross=Decimal("5000"), claimed_ss_tax=Decimal("310.00")
)
print(result.message)
# -> "❌ FICA Error: Expected $68.20 (Hit Limit)"

# 2. India Crypto Check
in_tax = TaxVerifier(jurisdiction="INDIA")
res = in_tax.verify_india_crypto(losses={"VDA": Decimal("-5000")}, gains=None)
print(res.message)
# -> "⚠️ Section 115BBH Alert: VDA loss cannot be set off."

🧾 Accounts Payable Verification

qwed-tax verifies tax decisions in the Procure-to-Pay cycle for AI Agents:

• Validation: Checks GSTIN/VAT ID formats.
• Verification: Blocks Input Tax Credit (ITC) on "Personal" categories (Food, Cars, Gifts).
• Withholding: Verifies TDS/Retention amounts before commercial payment.

🌐 TypeScript SDK

Run verification checks proactively in the browser/frontend.

npm install @qwed-ai/tax

import { TaxPreFlight } from '@qwed-ai/tax';

const result = TaxPreFlight.audit({
  action: "hire",
  worker_type: "1099",
  worker_facts: { provides_tools: true, reimburses_expenses: true, indefinite_relationship: true } // implies Employee
});

if (!result.allowed) {
   alert(" Verification Block: " + result.blocks.join(", "));
}

🔐 Fail-Closed Contract: TaxPreFlight is strict by design. Missing, ambiguous, or unsupported intent payloads are blocked (allowed = false) rather than treated as a successful verification.

⚡ Usage (Frontend)

from qwed_tax.verifier import TaxPreFlight

preflight = TaxPreFlight()
report = preflight.audit_transaction({
    "action": "hire",
    "worker_type": "1099",
    "worker_facts": {
        "provides_tools": True,
        "reimburses_expenses": True,
        "indefinite_relationship": True
    }, # Employee traits
    "state": "NY", 
    "sales_data": {"amount": 600000} # Crosses Nexus
})

if not report["allowed"]:
    print(f"🛑 BLOCKED: {report['blocks']}")

ℹ️ A claim is considered verified only when a supported action is provided and at least one deterministic check is actually executed.

ℹ️ Python: worker_type must be one of W2 / W-2 / EMPLOYEE or 1099 / 1099-NEC / CONTRACTOR / INDEPENDENT CONTRACTOR (any case). Other text is rejected, not interpreted. All three worker_facts must be booleans. The TypeScript SDK compares worker_type exactly, so pass "W2" or "1099" there.

📂 Examples

Check the examples/ directory for runnable scripts:

• examples/demo_payroll.py: US FICA & Payroll verification.
• examples/demo_advanced.py: Complex Investment & Trading checks.

🗺️ Roadmap

Expanding verification guard coverage to more jurisdictions and tax rules. Check out our Detailed Roadmap for 2026 plans including:

• 🇬🇧 UK (HMRC) & 🇨🇦 Canada (CRA) Verification Guards
• Transfer Pricing & BEPS Verification Guards
• ERP Verification Connectors — verify tax decisions before they enter SAP/Oracle

📦 Related Packages

🤝 Contributing

We welcome contributions from Tax Experts and Developers! See CONTRIBUTING.md for guidelines.

📄 License

Apache 2.0