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

# Streaming

> TypeScript streaming API — StreamEvent, StreamEventType, and async iterators for real-time cascade output.

# Streaming

`CascadeAgent` supports streaming via `streamEvents()` and `stream()` async iterators.

## streamEvents()

```typescript theme={null}
import { CascadeAgent, StreamEventType } from '@cascadeflow/core';

const agent = new CascadeAgent({ models: [...] });

for await (const event of agent.streamEvents('Explain TypeScript')) {
  switch (event.type) {
    case StreamEventType.ROUTING:
      console.log(`Routing: ${event.data.strategy}`);
      break;
    case StreamEventType.CHUNK:
      process.stdout.write(event.content);
      break;
    case StreamEventType.DRAFT_DECISION:
      console.log(`Draft ${event.data.accepted ? 'accepted' : 'rejected'}`);
      break;
    case StreamEventType.COMPLETE:
      console.log(`\nModel: ${event.data.model}, Cost: $${event.data.cost}`);
      break;
  }
}
```

## StreamEvent

```typescript theme={null}
interface StreamEvent {
  type: StreamEventType;
  content: string;
  data: StreamEventData;
}
```

| Field     | Type              | Description                        |
| --------- | ----------------- | ---------------------------------- |
| `type`    | `StreamEventType` | Event type                         |
| `content` | `string`          | Content chunk (for `CHUNK` events) |
| `data`    | `StreamEventData` | Event metadata                     |

## StreamEventType

| Value            | Description                        |
| ---------------- | ---------------------------------- |
| `ROUTING`        | Routing decision made              |
| `CHUNK`          | Content chunk received             |
| `DRAFT_DECISION` | Draft quality validation result    |
| `SWITCH`         | Switching from drafter to verifier |
| `COMPLETE`       | Streaming complete                 |
| `ERROR`          | Error occurred                     |

## StreamEventData

| Field      | Type      | Description                                      |
| ---------- | --------- | ------------------------------------------------ |
| `model`    | `string`  | Current model name                               |
| `phase`    | `string`  | Current phase (`"draft"` or `"verify"`)          |
| `strategy` | `string`  | Routing strategy used                            |
| `accepted` | `boolean` | Whether draft was accepted (on `DRAFT_DECISION`) |
| `cost`     | `number`  | Running cost (on `COMPLETE`)                     |

## StreamEventsOptions

Same as `RunOptions` — all parameters from `agent.run()` are accepted.

```typescript theme={null}
for await (const event of agent.streamEvents('Query', {
  maxTokens: 500,
  temperature: 0.7,
  systemPrompt: 'You are a helpful assistant.',
})) {
  // ...
}
```