> ## Documentation Index
> Fetch the complete documentation index at: https://docs.speckle.systems/llms.txt
> Use this file to discover all available pages before exploring further.

# Service registration

> AddSpeckleSdk bootstrap — copy from Scripts for automation, customize for connectors

Call **`AddSpeckleSdk`** once at startup before resolving **`IOperations`** or **`IClientFactory`**. **For scripts:** copy the bootstrap from [Automate with scripts](/developers/sdks/dotnet/getting-started/scripts-and-notebooks) — do not customize unless you need extra assemblies. **For connectors:** see [Dependency injection (connectors)](/developers/sdks/dotnet/concepts/dependency-injection).

## AddSpeckleSdk

<ResponseField name="application" type="Application" required>
  Describes your host application. `Application` is a record: `Application(string Name, string Slug)`.
</ResponseField>

<ResponseField name="applicationVersion" type="string" required>
  Your application's version string, used for telemetry and diagnostics.
</ResponseField>

<ResponseField name="speckleVersion" type="string?" default="null">
  Overrides the reported Speckle.Sdk version. Defaults to the assembly version.
</ResponseField>

<ResponseField name="assemblies" type="IEnumerable<Assembly>? / params Assembly[]">
  Assemblies containing custom `Base`-derived types (including `Speckle.Objects`, if used) that `TypeLoader` should be able to resolve during deserialization.
</ResponseField>

```csharp Example lines icon="https://mintcdn.com/speckle/VtRPWzmN-ULoLfIv/images/developers/sdks/csharp.svg?fit=max&auto=format&n=VtRPWzmN-ULoLfIv&q=85&s=f2970e3b8bd4a2c7899b46211a42f251" theme={null}
public static IServiceCollection AddSpeckleSdk(
    this IServiceCollection serviceCollection,
    Application application,
    string applicationVersion,
    string? speckleVersion = null,
    IEnumerable<Assembly>? assemblies = null
);

// Overloads also accept assemblies as params Assembly[]
```

### What It Registers

| Registration                                                       | Registers                                                                                                                          |
| ------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------- |
| `TypeLoader.Initialize(...)`                                       | Type resolution for `speckle_type` across the provided assemblies                                                                  |
| `ISpeckleApplication` (singleton)                                  | Host application metadata (name, version, Speckle version)                                                                         |
| `ISdkActivityFactory` (singleton, no-op default)                   | Tracing hook — provide your own to integrate with OpenTelemetry                                                                    |
| `ISdkMetricsFactory` (singleton, no-op default)                    | Metrics hook                                                                                                                       |
| Every interface-implementing class in the SDK assembly (transient) | `IOperations`, `IClientFactory`, `IAccountFactory`, `IAccountManager`, `IServerTransportFactory`, `ISendPipelineFactory`, and more |
| `AddLogging()`                                                     | `Microsoft.Extensions.Logging` integration                                                                                         |

## Application

```csharp Example lines icon="https://mintcdn.com/speckle/VtRPWzmN-ULoLfIv/images/developers/sdks/csharp.svg?fit=max&auto=format&n=VtRPWzmN-ULoLfIv&q=85&s=f2970e3b8bd4a2c7899b46211a42f251" theme={null}
public record Application(string Name, string Slug);
```

<Note>
  `Application` has no required format for `Slug` beyond being a stable identifier for your app — it's used for telemetry, not validation.
</Note>

## Registering Custom Activity or Metrics Factories

If you want tracing or metrics integration, register your own implementation **before** calling `AddSpeckleSdk` — the SDK uses `TryAddSingleton`, which only registers a default if one isn't already present:

```csharp Example lines icon="https://mintcdn.com/speckle/VtRPWzmN-ULoLfIv/images/developers/sdks/csharp.svg?fit=max&auto=format&n=VtRPWzmN-ULoLfIv&q=85&s=f2970e3b8bd4a2c7899b46211a42f251" theme={null}
services.AddSingleton<ISdkActivityFactory, MyOpenTelemetryActivityFactory>();
services.AddSpeckleSdk(new Application("My App", "my-app"), "1.0.0");
```

## FAQ

<AccordionGroup>
  <Accordion title="What is the minimum bootstrap for a script?">
    `new ServiceCollection().AddSpeckleSdk(new Application(...), "1.0.0").BuildServiceProvider()` — see the canonical helper in [Automate with scripts](/developers/sdks/dotnet/getting-started/scripts-and-notebooks).
  </Accordion>

  <Accordion title="Do I need to pass Speckle.Objects in assemblies?">
    Yes if you send or receive geometry types from that package. Without it, those types deserialize as plain `Base`.
  </Accordion>
</AccordionGroup>

## Next Steps

<CardGroup cols={3}>
  <Card title="Dependency injection (connectors)" icon="book" href="/developers/sdks/dotnet/concepts/dependency-injection">
    What AddSpeckleSdk registers
  </Card>

  <Card title="Automate with scripts" icon="terminal" href="/developers/sdks/dotnet/getting-started/scripts-and-notebooks">
    Minimal bootstrap example
  </Card>

  <Card title="Client API" icon="code" href="/developers/sdks/dotnet/api-reference/client">
    Resolve IClientFactory after registration
  </Card>
</CardGroup>