# Interface IHubOperationBuilder

OptimaJet.Workflow.Api.Configuration.IHubOperationBuilder

Registers callbacks for client invocations of one library-owned hub.

Namespace: [OptimaJet.Workflow.Api.Configuration](https://api.workflowengine.io/web-api/OptimaJet.Workflow.Api.Configuration/)

```csharp
public interface IHubOperationBuilder
```

## Methods

`IHubOperationBuilder OnBefore(Func<IHubOperationContext, ValueTask<HubOperationResult?>> callback)` 

Adds argument preparation. Null continues; a result skips remaining before/authorization callbacks and the method, then runs OnAfter.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `callback` | `Func<IHubOperationContext, HubOperationResult>` | The preparation callback. |

### Returns

| Type | Description |
| --- | --- |
| `IHubOperationBuilder` | This builder. |

### Remarks

Only this stage permits ReplaceArguments. Transport binding and ASP.NET authorization run first.

`IHubOperationBuilder OnAuthorize(Func<IHubOperationContext, ValueTask<bool>> callback)` 

Adds authorization over the final arguments. The first false produces a failed completion and skips remaining authorization callbacks and the method.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `callback` | `Func<IHubOperationContext, Boolean>` | The authorization callback. |

### Returns

| Type | Description |
| --- | --- |
| `IHubOperationBuilder` | This builder. |

### Remarks

Runs even when built-in security is disabled. Do not mutate arguments in this stage.

`IHubOperationBuilder OnAfterSuccess(Func<IHubOperationContext, object?, ValueTask<object?>> callback)` 

Adds a transformation of the original method's non-null result, preserving its declared payload type.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `callback` | `Func<IHubOperationContext, Object, Object>` | The result transformation. |

### Returns

| Type | Description |
| --- | --- |
| `IHubOperationBuilder` | This builder. |

### Remarks

Skipped for void/null returns, failures, short circuits and exception fallbacks. A stream is one return object; its items are outside this pipeline.

`IHubOperationBuilder OnAfter(Func<IHubOperationContext, HubOperationResult, ValueTask<HubOperationResult>> callback)` 

Adds a transformation of the final completion, including short circuits, authorization denial and recovered exceptions.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `callback` | `Func<IHubOperationContext, HubOperationResult, HubOperationResult>` | The transformation, which must return a non-null completion. |

### Returns

| Type | Description |
| --- | --- |
| `IHubOperationBuilder` | This builder. |

`IHubOperationBuilder OnException(Func<IHubOperationContext, Exception, ValueTask<HubOperationResult?>> callback)` 

Adds exception recovery. Null passes the original exception to the next callback; a completion handles it.

### Parameters

| Name | Type | Description |
| --- | --- | --- |
| `callback` | `Func<IHubOperationContext, Exception, HubOperationResult>` | The recovery callback. |

### Returns

| Type | Description |
| --- | --- |
| `IHubOperationBuilder` | This builder. |

### Remarks

Covers callbacks and method invocation, not binding, serialization, connection lifecycle or stream enumeration. Connection cancellation and protected tenant/process failures bypass recovery. Unhandled errors preserve their stack. Recovery failures do not re-enter recovery. A fallback before OnAfter passes through it once; a fallback for an OnAfter error is sent directly.

## Remarks

Stages run in order: OnBefore, OnAuthorize, method, OnAfterSuccess, OnAfter. Each stage preserves registration order. Repeated selection shares the builder; freezing rejects further changes. Callbacks wrap method invocation, not connection lifecycle, outgoing events, or stream enumeration. Resolve scoped dependencies from the invocation context's Services.

[Previous HubOperationResult](https://api.workflowengine.io/web-api/OptimaJet.Workflow.Api.Configuration/HubOperationResult/) [Next IHubOperationContext](https://api.workflowengine.io/web-api/OptimaJet.Workflow.Api.Configuration/IHubOperationContext/)