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

# Responses

> WebSocket response formats and event structures

## News Data Response

Receive real-time news articles through the `news:data` event.

```javascript theme={null}
socket.on('news:data', (response) => {
  console.log('New articles:', response);
});
```

**Response Structure:**

```json theme={null}
{
  "type": "news",
  "data": {
    "news": [
      {
        "_id": "67850d7b0123456789abcde1",
        "title": "Breaking: Fed Issues Emergency Statement",
        "koTitle": "속보: 연준 긴급성명 발표",
        "content": "The Federal Reserve issued an unexpected emergency statement addressing current market volatility and reaffirming its commitment to price stability. The statement comes amid heightened concerns over inflation and economic uncertainty.",
        "koContent": "연방준비제도이사회가 현재의 시장 변동성을 다루고 물가 안정에 대한 약속을 재확인하는 예상치 못한 긴급 성명을 발표했습니다. 이 성명은 인플레이션과 경제 불확실성에 대한 우려가 높아지는 가운데 나왔습니다.",
        "url": "https://www.byul.ai/news/fed-emergency-statement",
        "date": "2024-01-15T14:30:00.000Z",
        "source": "byul.ai",
        "timestamp": 1705415400,
        "importanceScore": 10,
        "category": "fed",
        "symbols": [],
        "sentiment": "neutral"
      }
    ],
    "hasMore": false,
    "nextCursor": null,
    "total": 1
  },
  "timestamp": "2024-01-15T14:30:15Z",
  "isRealTimeUpdate": true
}
```

**Response Fields:**

* `type` - Event type ("news")
* `data` - News data object containing `news` array, `hasMore`, `nextCursor`, `total`
* `timestamp` - Server transmission time
* `isRealTimeUpdate` - Whether this is a real-time update

## Connection Status Response

Monitor connection health and usage statistics.

```javascript theme={null}
socket.on('connection:status', (status) => {
  console.log('Connection status:', status);
});
```

**Response Structure:**

```json theme={null}
{
  "status": "connected",
  "connectionsUsed": 1,
  "maxConnections": 10,
  "plan": "pro",
  "rateLimit": {
    "remaining": 119,
    "resetTime": "2024-01-15T15:00:00Z"
  }
}
```

**Status Fields:**

* `status` - Connection state (`connected`, `disconnected`, `limited`)
* `connectionsUsed` - Current active connections
* `maxConnections` - Plan connection limit
* `plan` - Subscription plan type
* `rateLimit` - Rate limiting information

## Subscription Confirmation

Receive confirmation when subscriptions are activated.

```javascript theme={null}
socket.on('news:subscribed', (confirmation) => {
  console.log('Subscription confirmed:', confirmation);
});
```

**Response Structure:**

```json theme={null}
{
  "type": "news",
  "params": {
    "limit": 20,
    "minImportance": 5,
    "symbol": "AAPL"
  },
  "message": "Successfully subscribed to news feed - 실시간 업데이트 활성화됨"
}
```

**Confirmation Fields:**

* `type` - Subscription type
* `params` - Applied filter settings
* `message` - Confirmation message

## Batch News Response

Large news updates may be delivered as batches.

```javascript theme={null}
socket.on('news:data', (batch) => {
  console.log(`Batch update: ${batch.articles.length} articles`);
});
```

**Batch Structure:**

```json theme={null}
{
  "type": "news_batch",
  "articles": [
    // Array of article objects
  ],
  "batchId": "batch_20240115_143015",
  "totalArticles": 5,
  "timestamp": "2024-01-15T14:30:15Z",
  "reason": "high_volume"
}
```

**Batch Fields:**

* `batchId` - Unique batch identifier
* `totalArticles` - Total articles in batch
* `reason` - Batching reason (`high_volume`, `scheduled`)

## Ping Response

Server may send ping messages to check connection health.

```javascript theme={null}
socket.on('ping', (data) => {
  console.log('Ping received:', data.timestamp);
  
  // Respond with pong
  socket.emit('pong', {
    timestamp: Date.now()
  });
});
```

**Ping Structure:**

```json theme={null}
{
  "timestamp": "2024-01-15T14:30:00Z",
  "serverId": "ws-server-01"
}
```

## Response Handling Best Practices

### Type Checking

Always validate response structure:

```javascript theme={null}
socket.on('news:data', (response) => {
  if (response.type && response.data && response.data.news && Array.isArray(response.data.news)) {
    response.data.news.forEach(article => {
      if (article._id && article.title) {
        processArticle(article);
      }
    });
  }
});
```

### Error Handling

Handle malformed responses gracefully:

```javascript theme={null}
socket.on('news:data', (response) => {
  try {
    const { data, timestamp } = response;
    const { news } = data;
    
    if (!news || !Array.isArray(news)) {
      console.warn('Invalid news array received');
      return;
    }
    
    console.log(`Processing ${news.length} articles`);
    news.forEach(processArticle);
    
  } catch (error) {
    console.error('Error processing news response:', error);
  }
});
```

### Response Logging

Log responses for debugging:

```javascript theme={null}
const logResponse = (eventName, data) => {
  console.log(`[${new Date().toISOString()}] ${eventName}:`, {
    type: data.type || 'unknown',
    count: data.data?.news?.length || data.data?.total || 0,
    timestamp: data.timestamp
  });
};

socket.on('news:data', (data) => logResponse('news:data', data));
socket.on('connection:status', (data) => logResponse('connection:status', data));
```