# Type Alias StreamChunk

StreamChunk:
| {
type: "content_block_start";
index: number;
contentBlock: ContentBlock;
}
| {
type: "content_block_delta";
index: number;
delta: { type: "text_delta"; text: string };
}
| { type: "content_block_stop"; index: number }
| { type: "message_start"; message: { model: string } }
| {
type: "message_delta";
delta: { stop_reason: StopReason };
usage: TokenUsage;
}
| { type: "message_stop" }

Chunk from a streaming response.

- Defined in packages/nexus-agents/src/core/types/model.ts:128