Natural/ADABAS Public Sector: Documenting Legacy Tax Filing Logic via Visual Reverse Engineering

The state revenue department’s core tax engine is a black box. Written in Software AG’s Natural and running on an ADABAS database, it has processed millions of filings since 1984. But the original architects are retiring, and the documentation—if it ever existed—is a stack of yellowed binders that haven't been updated since the Clinton administration. When a new legislative mandate requires a change to tax credit calculations, the risk of "breaking the mainframe" isn't just a meme; it’s a multi-million dollar liability.

For agencies involved in naturaladabas public sector documenting, the challenge isn't just reading the code; it’s understanding the business intent buried under forty years of "spaghetti" logic. According to Replay's analysis, 67% of legacy systems lack any form of usable documentation, leaving modern developers to play a high-stakes game of reverse-engineering via trial and error.

TL;DR: Documenting legacy Natural/ADABAS tax systems is notoriously slow, taking an average of 40 hours per screen. Replay uses Visual Reverse Engineering to convert recorded user workflows into documented React code and Design Systems, reducing modernization timelines by 70% and moving from 18-month projects to delivery in weeks.

The Documentation Crisis in Government Revenue Systems#

The public sector is currently facing a "grey tsunami." As the workforce that built the initial Natural/ADABAS systems reaches retirement age, the institutional knowledge of how tax filing logic actually functions is evaporating. This creates a massive bottleneck for Legacy Modernization.

The technical debt is staggering. Industry experts recommend that agencies address the $3.6 trillion global technical debt before it becomes a systemic failure. In the context of tax filing, this debt manifests as:

• •Invisible Business Rules: Validation logic for tax credits hidden in nested
  text

  IF...THEN
  statements within Natural programs.
• •Data Silos: ADABAS files that use non-relational structures, making it nearly impossible for modern BI tools to extract meaning without a translation layer.
• •UI Inconsistency: "Green screens" (Natural Maps) that require specialized terminal emulators and offer zero accessibility for modern citizens.

Video-to-code is the process of capturing these legacy interactions as video and using AI-driven visual analysis to generate functional, documented frontend components.

Why Manual NaturalADABAS Public Sector Documenting Fails#

Traditionally, documenting these systems required a "Clean Room" approach: a developer would sit with a legacy expert, watch them navigate a terminal, take notes, and then attempt to write a functional specification. This manual process takes approximately 40 hours per screen.

The failure rate of 70% in legacy rewrites is largely attributed to the "Documentation Gap." When you try to rewrite a system you don't fully understand, you miss the edge cases—the "weird" tax exemption for 19th-century farm equipment that is still on the books and hard-coded into the Natural logic.

The Replay Methodology: Documenting Tax Logic through Observation#

Instead of reading the source code first, Replay focuses on the observed behavior of the system. By recording a tax officer or a citizen navigating the filing process, Replay’s AI Automation Suite identifies patterns, input fields, and validation triggers.

Step 1: Capturing the Workflow (Flows)#

In the naturaladabas public sector documenting process, the first step is recording the "Happy Path" and "Edge Case" filings. Replay captures the terminal interaction, identifying where data is entered and how the system responds.

Step 2: Generating the Component Library#

Replay’s "Library" feature takes these recordings and extracts a unified Design System. For a tax agency, this means turning a cryptic "MAP" definition into a reusable React component.

Step 3: Mapping Logic to Blueprints#

The "Blueprints" editor allows architects to see the underlying logic. If a specific field in the Natural Map only appears when "Exemption Code X" is entered, Replay identifies that conditional logic and documents it within the React code.

Technical Implementation: From Natural MAP to React Component#

Let's look at what this looks like in practice. A typical Natural MAP might define a screen for "Income Declaration."

natural
/* Legacy Natural MAP Definition (Conceptual) */
01 INCOME-MAP
  02 #TAX-YEAR (A4)  /* Input: Tax Year */
  02 #GROSS-INC (N10) /* Input: Gross Income */
  02 #DEPENDENTS (N2) /* Input: Number of Dependents */
  02 #MSG (A40)       /* Output: Validation Message */
...
IF #GROSS-INC > 100000 AND #DEPENDENTS < 1
  MOVE 'High Income Surcharge Applies' TO #MSG
END-IF

When Replay processes a recording of this screen, it doesn't just give you a screenshot. It generates a documented, type-safe React component that mirrors the behavior and prepares it for a modern Component Library.

The Modernized React Output#

typescript
import React, { useState, useEffect } from 'react';
import { TextField, Alert, Card } from '@gov-design-system/core';

/**
 * @description Documented Tax Filing Logic extracted from Natural/ADABAS Map: INCOME-MAP
 * @logic Surcharge applied if Gross Income > 100k and Dependents < 1
 */
export const IncomeDeclaration: React.FC = () => {
  const [taxYear, setTaxYear] = useState<string>('');
  const [grossIncome, setGrossIncome] = useState<number>(0);
  const [dependents, setDependents] = useState<number>(0);
  const [message, setMessage] = useState<string | null>(null);

  useEffect(() => {
    // Replay identified this conditional logic from user workflow recordings
    if (grossIncome > 100000 && dependents < 1) {
      setMessage('High Income Surcharge Applies');
    } else {
      setMessage(null);
    }
  }, [grossIncome, dependents]);

  return (
    <Card title="Income Declaration">
      <TextField 
        label="Tax Year" 
        value={taxYear} 
        onChange={(e) => setTaxYear(e.target.value)} 
      />
      <TextField 
        label="Gross Income" 
        type="number" 
        value={grossIncome} 
        onChange={(e) => setGrossIncome(Number(e.target.value))} 
      />
      <TextField 
        label="Number of Dependents" 
        type="number" 
        value={dependents} 
        onChange={(e) => setDependents(Number(e.target.value))} 
      />
      {message && <Alert severity="info">{message}</Alert>}
    </Card>
  );
};

This code is not just a "guess." It is built from the visual reality of the legacy system. By using Replay, the 18-month average enterprise rewrite timeline is compressed into weeks because the documentation and the code generation happen simultaneously.

Scaling NaturalADABAS Public Sector Documenting for Regulated Environments#

Public sector projects have unique requirements that generic AI tools can't meet. When dealing with sensitive tax data, security is paramount. Visual Reverse Engineering must happen within a secure perimeter.

1. •SOC2 and HIPAA Compliance: Replay is built for regulated environments. Whether it's healthcare data or tax records, the platform ensures that PII (Personally Identifiable Information) is handled according to federal standards.
2. •On-Premise Availability: For agencies that cannot use the cloud, Replay offers on-premise deployments. This allows for naturaladabas public sector documenting to occur entirely within the agency's firewall.
3. •Audit Trails: Every component generated by Replay includes a link back to the original recording. This "provenance" is vital for government audits, proving that the new React logic exactly matches the legacy system's behavior.

Advanced Architecture: Managing ADABAS State in React#

One of the hardest parts of naturaladabas public sector documenting is handling the state of multi-page filings. ADABAS is a transactional database, and Natural programs often use "Global Data Areas" (GDAs) to pass state between screens.

Replay's AI Automation Suite identifies these state transitions. If a user enters a Social Security Number on Screen 1 and it appears as a read-only header on Screen 5, Replay documents this data flow. This allows architects to build a modern state management solution (like Redux or React Context) that accurately reflects the legacy system's data lifecycle.

typescript
// Example of State Mapping generated by Replay
interface TaxFilingState {
  header: {
    ssn: string; // Captured from MAP-LOGIN
    filingStatus: string; // Captured from MAP-PROFILE
  };
  calculations: {
    adjustedGrossIncome: number; // Derived from MAP-INCOME
    totalCredits: number; // Derived from MAP-CREDITS
  };
}

/**
 * Replay Blueprint: Flow_Tax_Filing_v1
 * Documentation: This state object tracks the transition from the 
 * mainframe 'GDA-TAX-INFO' area into a modern front-end state.
 */

The Business Value of Visual Reverse Engineering#

The average enterprise rewrite takes 18 to 24 months. For a state agency, that's two filing seasons of running dual systems, double the maintenance cost, and double the risk. Replay targets 70% average time savings. By automating the documentation phase, agencies can move straight to the Modernization of their UI without the fear of losing critical business logic.

According to Replay's analysis, the cost of manual documentation is not just the hourly rate of the developer, but the opportunity cost of delayed features. When a legislative change takes 6 months to implement in Natural but could take 6 days in React, the "agility gap" becomes a political and economic burden.

Key Benefits for Public Sector Agencies:#

• •Reduced Risk: No more guessing what the code does; see what it does.
• •Accessibility (Section 508): Automatically convert legacy maps into WCAG-compliant React components.
• •Developer Onboarding: New developers can read documented React code instead of learning a dead language like Natural.
• •Future-Proofing: Once your logic is in a documented React library, you are no longer locked into any single vendor or mainframe provider.

For more information on these strategies, see our guide on Automating UI Documentation.

Frequently Asked Questions#

How does Replay handle PII during the recording process?#

Replay includes built-in PII masking and is SOC2 and HIPAA-ready. For highly sensitive government environments, we offer On-Premise deployments where no data ever leaves your secure network. The AI processes the visual patterns without needing to store sensitive taxpayer identifiers.

Can Replay document complex conditional logic in Natural?#

Yes. By recording multiple "Flows" (e.g., a filing for a single person vs. a filing for a married couple), Replay's AI identifies the differences in the UI and documents them as conditional logic in the generated React components. This captures the "as-is" behavior of the system, which is often more accurate than the "as-intended" documentation from decades ago.

Does this require access to the Natural source code?#

No. Replay is a visual reverse engineering platform. It documents the system based on the user interface and observed behavior. While having source code can be helpful for backend migration, Replay focuses on the most critical part of the user experience: the logic and data flow of the frontend.

What is the typical timeline for a Natural/ADABAS documenting project?#

While manual documentation can take years for a large tax system, Replay typically delivers a documented Component Library and functional "Flows" in a matter of weeks. We have seen agencies move from "discovery" to a "functional pilot" in less than a month.

Conclusion: The Path Forward for Tax Agencies#

The era of manual naturaladabas public sector documenting is over. The risks are too high, and the timelines are too long. As technical debt continues to mount globally, reaching $3.6 trillion, the public sector must adopt automated tools to preserve institutional knowledge and modernize service delivery.

Replay offers a bridge from the mainframe era to the modern web. By capturing the visual reality of your tax filing logic, we provide the documentation and the code needed to move forward with confidence. Don't let your agency's logic retire with your senior developers.

Ready to modernize without rewriting? Book a pilot with Replay