Architecture & Core Packages

The package consists of four main modules working together to convert, audit, remediate, and batch process documents, plus an optional browser-backed agent layer on top.

Architecture overview: PDF2HTML, Audit, and Remediate feed into the Batch orchestrator and produce accessible HTML output; the optional Agent layer hangs off Audit and Remediate to render, fix, re-render, and verify.

The optional agent layer (agent/) renders pages in a real headless browser to find issues static analysis cannot (computed contrast, focus visibility, the accessibility tree) and closes the loop by re-rendering to verify each fix. It is fully additive and off by default. See the Rendered & Agent Guide.

Core Packages

PDF2HTML

The PDF2HTML module handles conversion of PDF documents to HTML, including image extraction and processing.

PDF2HTML flow: a PDF source enters the PDF2HTML module, which runs BDA integration, image processing, and HTML generation, all producing the HTML output.

Key components:

  • Bedrock Data Automation (BDA) integration for PDF parsing
  • Image extraction and processing
  • HTML structure generation with preserved layout
  • Support for both single-page and multi-page output

Audit

The Audit module analyzes HTML for accessibility issues according to WCAG 2.1 and 2.2 guidelines.

Audit flow: HTML input enters the Audit module, which runs document, structure, image, and table checks, all feeding into a single audit report.

Key components:

  • Comprehensive accessibility checks
  • Issue severity classification
  • Detailed context information
  • Multiple report formats (HTML, JSON, text)

WCAG 2.2 scope: Because this tool produces static HTML converted from PDFs, it audits and remediates the WCAG 2.2 criteria that apply to non-interactive documents — currently 2.5.8 Target Size (Minimum). The remaining 2.2 criteria (2.5.7 Dragging Movements, 3.2.6 Consistent Help, 3.3.7 Redundant Entry, 3.3.8 Accessible Authentication) govern interactive web-application behaviors such as drag gestures, multi-page help, and authentication flows, which are out of scope for generated document content.

Remediate

The Remediate module fixes accessibility issues identified during audit.

Remediate flow: HTML with issues enters the Remediate module, which applies AI remediation strategies, direct fixes, and table remediation (direct and AI-powered), all producing remediated HTML.

Key components:

  • AI-powered remediation using Bedrock models
  • Direct fixes for common issues
  • Advanced table structure remediation
  • Image accessibility enhancements
  • Remediation reporting

See Accessibility Remediation for how each issue type is fixed.

Batch

The Batch module provides orchestration for processing documents at scale.

Batch flow: a document source enters the Batch module, which handles job management, AWS integration (S3 and DynamoDB), and the processing pipeline (Lambda), all converging on job completion.

Key components:

  • AWS service integrations
  • Job tracking and status management
  • Asynchronous processing
  • Lambda function support

The batch stages are wired into the event-driven managed pipeline — see the Deployable Pipeline Guide.