SSE Streaming

Subscribe to real-time span events via Server-Sent Events (SSE).

Connect to Stream

GET /api/v1/project/{project_id}/otel/sse

Optional query params:

• trace_id — stream only a single trace
• span_id — stream only a single span
• session_id — stream only a single session

Event Format

Events are sent with the event name span and a JSON payload:

event: span
data: {"trace_id":"...","span_id":"...","session_id":"...","user_id":"..."}

Example payload:

{
  "trace_id": "abc123",
  "span_id": "span-001",
  "session_id": "session-789",
  "user_id": "user-123"
}

JavaScript Example

const eventSource = new EventSource(
  'http://localhost:5388/api/v1/project/default/otel/sse'
);

eventSource.addEventListener('span', (event) => {
  const payload = JSON.parse(event.data);
  console.log('Span event:', payload);
});

eventSource.onerror = (error) => {
  console.error('SSE error:', error);
  eventSource.close();
};

Python Example

import json
import requests

url = 'http://localhost:5388/api/v1/project/default/otel/sse'

with requests.get(url, stream=True) as response:
    for line in response.iter_lines():
        if line and line.startswith(b'data: '):
            payload = json.loads(line.decode('utf-8').replace('data: ', ''))
            print('Span event:', payload)

With Authentication

When auth is enabled, include the token. Standard EventSource does not support custom headers—use a Node.js client or fetch with streaming instead.

Next Steps

• Traces API — query runs
• Spans API — query individual steps
• Sessions API — group related runs