---
title: Host startup
summary: Startup base class that enables legacy BOL authentication, registers services, and binds menu options.
status: draft
owner: SAIF IT Core Services
last_reviewed: 2026-10-12
library: BolMiddleware
reference_type: package
operation_id: OP-02
trigger: Consumer startup inheriting BolRazorLayoutStartup
---

# Host startup

`BolRazorLayoutStartup` is the base class a consumer application inherits for its startup. It builds on `OidcRazorStartup` from the platform packages and adds the BOL specific configuration.

| Field | Value |
| --- | --- |
| **Operation ID** | OP-02 |
| **Trigger** | Consumer startup inheriting `BolRazorLayoutStartup` |
| **Inputs** | `IConfiguration`, the `BasicAppMap` configuration section |
| **Outputs** | Registered BOL services and bound `IOptions<BasicAppMap>` |
| **Primary components** | `BolRazorLayoutStartup.ConfigureServices`, `BolRazorLayoutStartup.Configure` |
| **Entry point** | `src/BolMiddleware/BolRazorLayoutStartup.cs` |

## Steps

1. The constructor stores the supplied `IConfiguration` and calls the base constructor.
2. `ConfigureServices` sets `EnableLegacyBolAuthMiddleware` to true so the base startup adds the legacy BOL authentication middleware.
3. It calls the base `ConfigureServices` to register OIDC authentication and platform services.
4. It calls [Register BOL services](register-bol-services.md).
5. It binds the `BasicAppMap` configuration section to `IOptions<BasicAppMap>` and registers a scoped `IAppMap` that resolves a default `BasicAppMap` instance.
6. `Configure` only calls the base implementation; the resulting middleware order is unknown**.

## Process flow

The following diagram visualizes this operation's control flow.

```mermaid
flowchart TD
	Start([Startup]) --> S1[Enable legacy BOL auth middleware]
	S1 --> S2[Base ConfigureServices]
	S2 --> S3[Register BOL services]
	S3 --> S4[Bind BasicAppMap options]
	S4 --> S5[Register scoped IAppMap]
	S5 --> EndOk([Configure calls base])
```

## Failure and edge-case behavior

- `IAppMap` resolves an unbound default `BasicAppMap`, while views read the bound `IOptions<BasicAppMap>`; code that injects `IAppMap` sees empty values.
- `BolLayoutStartup.cs` is entirely commented out; it is dead code and has no effect.

> **Note:** Statements marked with `**` could not be confirmed; treat
> as unknown until verified.

## 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)
- [Security and authorization](../security-authorization.md)
- [Service registration](../service-registration.md)
- [API reference](../api/index.md)

## Sources
- src/BolMiddleware/BolRazorLayoutStartup.cs
- src/BolMiddleware/BolLayoutStartup.cs
- src/BolMiddleware/Models/MenuModels/BasicAppMap.cs