```ts
type Role = "user" | "assistant";
```

Defined in: [src/types/messages.ts:163](https://github.com/strands-agents/harness-sdk/blob/767b13fe59b76538208d5fefec89164fe067abe6/strands-ts/src/types/messages.ts#L163)

Role of a message in a conversation. Can be either ‘user’ (human input) or ‘assistant’ (model response).