--- title: Service registration summary: Services, options, startup base classes, middleware, and hosted services this library contributes to a consuming application. status: draft owner: Framework last_reviewed: 2026-10-02 library: SAIF.NetCore.NHibernate reference_type: package --- # Service registration This library exposes one modern registration surface, `AddNhibernateServices`/`AddNhibernateServices`, which registers a singleton `IUnitOfWorkFactory` and a scoped `UnitOfWorkAccessor` for any ASP.NET Core or generic-host application. It also retains 13 legacy registration methods on `IServicesNhibernateExtensions` as `[Obsolete("Due to functional changes between .net core 2.2 and .net core 3.1, this method is obsolete to avoid startup errors.", true)]` compile-time errors, kept only to force migration off the pre-.NET Core 3.1 API; none of the 13 registers any service at runtime, although their body mechanics differ (see the catalog below). ## Registration extension catalog | Extension method | Hosting context | Parameters | Source | | --- | --- | --- | --- | | `AddNhibernateServices(this IServiceCollection services, IEnumerable assemblyMappings, bool debugOutputSql)` | web \| API \| worker \| console | `assemblyMappings`: assemblies scanned for Fluent `ClassMap` and HBM mappings, fixed for the factory's lifetime. `debugOutputSql`: when `true`, attaches `SqlDebugOutputInterceptor` to stateful sessions (active only while a debugger is attached). | `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Extensions/IServicesCollectionExtensions.cs` | | `AddNhibernateServices(this IServiceCollection services, bool debugOutputSql = false)` | web \| API \| worker \| console | `T`: any type in the single mapping assembly to scan (`Assembly.GetAssembly(typeof(T))`). `debugOutputSql` defaults to `false`. | Same file | | `AddUnitOfWorkAccessor(this IServiceCollection services)` **[Obsolete, compile-error]** | N/A | None (no parameters beyond the `this IServiceCollection services` extension receiver) | `Extensions/IServicesNhibernateExtensions.cs` — no registration side effect; `return services;` only | | `UseOracleSession(this IServiceCollection services, IEnumerable mappings, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `mappings`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `UseOracleSession(this IServiceCollection services, Assembly mappings, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `mappings`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `UseOracleSession(this IServiceCollection services, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `T`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — `T` is actually used to resolve a mapping assembly before delegating to the `IEnumerable` overload above, which then discards it; still no registration side effect | Same file — no registration side effect | | `UsePostGreSqlSession(this IServiceCollection services, IEnumerable mappings, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `mappings`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `UsePostGreSqlSession(this IServiceCollection services, Assembly mappings, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `mappings`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `UsePostGreSqlSession(this IServiceCollection services, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `T`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; unlike the Oracle generic overload, `T` is never actually inspected (literal `return services;` body) | Same file — no registration side effect | | `UseSqlSession(this IServiceCollection services, IEnumerable mappings, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `mappings`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `UseSqlSession(this IServiceCollection services, Assembly mappings, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `mappings`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `UseSqlSession(this IServiceCollection services, bool statelessSession = false, bool formatSql = false, int batchSize = 20, bool showSql = false)` **[Obsolete, compile-error]** | N/A | `T`, `statelessSession`, `formatSql`, `batchSize`, `showSql` — all accepted but ignored; unlike the Oracle generic overload, `T` is never actually inspected (literal `return services;` body) | Same file — no registration side effect | | `AddOracleUnitOfWork(this IServiceCollection services, string unitOfWorkInstanceName, string oracleInstance, string userName)` **[Obsolete, compile-error]** | N/A | `unitOfWorkInstanceName`, `oracleInstance`, `userName` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `AddSqlUnitOfWork(this IServiceCollection services, string unitOfWorkInstanceName, string sqlServerName, string sqlServerInstance, string userName)` **[Obsolete, compile-error]** | N/A | `unitOfWorkInstanceName`, `sqlServerName`, `sqlServerInstance`, `userName` — all accepted but ignored; no registration side effect | Same file — no registration side effect | | `AddPostGreSqlUnitOfWork(this IServiceCollection services, string unitOfWorkInstanceName, string serverName, string instance, string userName)` **[Obsolete, compile-error]** | N/A | `unitOfWorkInstanceName`, `serverName`, `instance`, `userName` — all accepted but ignored; no registration side effect | Same file — no registration side effect | All 13 rows marked **[Obsolete, compile-error]** above are `[Obsolete("Due to functional changes between .net core 2.2 and .net core 3.1, this method is obsolete to avoid startup errors.", true)]` on `IServicesNhibernateExtensions` — calling any of them is a **compile-time error** (the `true` argument), and every one of the 13 has zero registration side effect and no service lifetime to report, even though `UseOracleSession` performs a discarded `Assembly.GetAssembly(typeof(T))` call internally before its final no-op delegation (see [BR-NH-16](business-rules.md#br-nh-16-legacy-registration-api-is-a-compile-time-error)). The checked-in `README.md` still documents this obsolete API and should not be treated as current.* ## Service registration catalog | Service type | Implementation | Lifetime | Registered by | Condition | Source | | --- | --- | --- | --- | --- | --- | | `IUnitOfWorkFactory` | factory lambda: `new UnitOfWorkFactory(assemblyMappings, debugOutputSql)` | Singleton | `AddNhibernateServices` (internal `AddUnitOfWorkFactory`) | Always | `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Extensions/IServicesCollectionExtensions.cs` | | `UnitOfWorkAccessor` | `UnitOfWorkAccessor` (concrete class, resolves `IUnitOfWorkFactory` + `IOptionsSnapshot` from DI) | Scoped | `AddNhibernateServices` | Always | Same file | ## Options configuration | Options type | Named instance | Configured by | Configuration keys / services read | Source | | --- | --- | --- | --- | --- | | `UnitOfWorkOptions` | One per `ConfigureUnitOfWorkOptions` subclass's `UniqueName`, registered by the consuming application via `services.ConfigureOptions()` | Consumer-authored `ConfigureUnitOfWorkOptions` subclass (`IConfigureNamedOptions`) | None owned by this library — see [Configuration](configuration.md) for the full `UnitOfWorkOptions` settings catalog (UO1–UO7) | `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Options/ConfigureUnitOfWorkOptions.cs`, `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Options/UnitOfWorkOptions.cs` | ## Required-but-not-registered services | Service type | Consumer | Expected source | | --- | --- | --- | | `IEnvironmentClient` | Consumer's `ConfigureUnitOfWorkOptions` subclass constructor | Host application, typically via `SAIF.NetCore.ServiceExtensions` registering `SAIF.NetCore.EnvironmentClient` | | `IDBConnectionClient` | Consumer's `ConfigureUnitOfWorkOptions` subclass constructor | Host application, typically via `SAIF.NetCore.ServiceExtensions` registering `SAIF.NetCore.DBConnectionClient` | | `IOptionsSnapshot` / options infrastructure | `UnitOfWorkAccessor` | Host application (ASP.NET Core / Generic Host registers `AddOptions` by default) | | A `ConfigureUnitOfWorkOptions` subclass itself | `UnitOfWorkAccessor.UnitOfWork(key)` (via `IOptionsSnapshot.Get`) | Host application — one subclass per logical database, registered with `services.ConfigureOptions()` | No startup base classes, feature flags, middleware pipeline, or hosted services/health checks exist in this library — it contributes no `IApplicationBuilder` or `IHostedService` surface. ## Related documentation - [Index](index.md) - [Overview](overview.md) - [Architecture](architecture.md) - [Dependencies](dependencies.md) - [Configuration](configuration.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) > **Note:** Statements marked with `*` were inferred from code structure, naming > conventions, or contextual evidence where direct confirmation was not available > in source artifacts. Statements marked with `**` could not be confirmed; treat > as unknown until verified. ## Sources - `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Extensions/IServicesCollectionExtensions.cs` - `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Extensions/IServicesNhibernateExtensions.cs` - `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/UnitOfWorkAccessor.cs` - `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Options/ConfigureUnitOfWorkOptions.cs` - `src/SAIF.NetCore.Nhibernate/SAIF.NetCore.NHibernate/SAIF.NetCore.NHibernate/Options/UnitOfWorkOptions.cs`