---
title: SAIF.Domain overview
summary: High-level purpose, scope, and responsibilities for this library.
status: draft
owner: SAIF Doc Gen
last_reviewed: 2026-09-24
library: SAIF.Domain
reference_type: package
---

# SAIF.Domain overview

> **Documentation context:** Packaged Component (NuGet)

SAIF.Domain is the domain-logic layer of the SAIF platform's electronic-billing (ebilling), claims, and policy-correspondence subsystems: it wraps NHibernate-mapped entities supplied by SAIF.Data and SAIF.Data.Guidewire in domain objects that expose business behaviour, and it is consumed exclusively by SAIF.Services in production. It ships inside the `SAIF.SAIFCode.Core` NuGet package as `lib\net462\SAIF.Domain.dll`.

## Purpose
- Assigns, indexes, and generates CBP (converted-bill-processing) bills from inbound electronic bills, parses and builds the surrounding EDI files (837, 835, 277, 999-style acknowledgements), and generates explanation-of-benefits (EOB) records from Guidewire payment extracts.
- Manages bill audits and audit notes, bill regeneration, policy certificate-holder lifecycle, document-packet assembly for policy correspondence, and a Guidewire-backed `Claim` read model that merges legacy WCIS data with live ClaimCenter API data.
- Consumed exclusively by SAIF.Services in production, which owns all transaction (`IUnitOfWork.Begin`/`Commit`) boundaries around calls into this library.

## Responsibilities
- Wrap SAIF.Data entities in domain objects that expose behaviour methods such as `Bill.ModifyStatus`, `Bill.SendToAudit`, `Audit.AllowAllServices`, and `CertificateHolder.Expire`.
- Drive the ebilling lifecycle end to end: patient/provider/service indexing, bill assignment, CBP bill generation, EDI file parsing/building, and EOB generation.
- Manage bill audits, audit notes, and bill regeneration.
- Manage policy certificate-holder lifecycle (create, update, expire, reinstate, supersede).
- Present a Guidewire-backed `Claim` read model for consumers that need combined legacy/ClaimCenter claim data.
- Generate document packets for policy correspondence.

## Key components
- `DomainBase<TItem>` / `DomainQueryBase<TItem,TQueryProvider>` / `DomainRepositoryBase<TItem>`: shared base classes every domain wrapper builds on.
- `BillAssignment`, `PatientIndexer`, `ProviderIndexerV2`, `BillServiceIndexer`, `GenerateCbpBills`: the ebilling assignment/indexing/CBP-generation pipeline.
- `File837Extractor`, `File835Builder`, `File277CaBuilder`, `File837AckBuilder`, `EdiBuildSegments`: EDI file parsing and building.
- `EobBuilder`, `EobGenerator`, `EobExtensions`: EOB record generation and rendering.
- `Bill`, `Audit`, `AuditNote`, `BillRegenerator`: bill lifecycle, auditing, and note-taking.
- `Claim`, `ClaimAdjuster`, `ClaimReserveGenerator`, `Worker`: the Guidewire-backed claim read model.
- `CertificateHolder`: policy certificate-holder lifecycle management.
- `PacketManager`, `PacketGenerator`, `PacketDefinition`: document-packet assembly for policy correspondence.

## Related documentation
- [Index](index.md)
- [Architecture](architecture.md)
- [Dependencies](dependencies.md)
- [Operations and processes](operations-processes.md)
- [Business rules](business-rules.md)
- [Database tables](database-tables.md)
- [SQL catalog](sql/index.md)
- [API reference](api/index.md)

## Sources
- `Domain/SAIF.Domain/SAIF.Domain.csproj`
- `Core/SAIF.Core/SAIF.SAIFCode.Core.nuspec`
- `Domain/SAIF.Domain/packages.config`