> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-5b6e02fd.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# System - Go SDK

> System type definition

<Warning>
  The Go SDK and docs are currently in beta.
  Report issues on [GitHub](https://github.com/OpenRouterTeam/go-sdk/issues).
</Warning>

## Supported Types

###

```go lines theme={null}
system := components.CreateSystemStr(string{/* values here */})
```

###

```go lines theme={null}
system := components.CreateSystemArrayOfAnthropicTextBlockParam([]components.AnthropicTextBlockParam{/* values here */})
```

## Union Discrimination

Use the `Type` field to determine which variant is active, then access the corresponding field:

```go lines theme={null}
switch system.Type {
	case components.SystemTypeStr:
		// system.Str is populated
	case components.SystemTypeArrayOfAnthropicTextBlockParam:
		// system.ArrayOfAnthropicTextBlockParam is populated
}
```