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

Defined in: [src/types/messages.ts:163](https://github.com/strands-agents/harness-sdk/blob/576da59fdc411b55036a7cf66d4e1659a67d4d0d/strands-ts/src/types/messages.ts#L163)

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