Advanced Echo Server

Server-Sent Events (SSE)

Stream JSON events to clients using Server-Sent Events (SSE) at /sse. A web-based tester is available at /web-sse. Events include a counter and timestamp, sent at intervals set by ECHO_SSE_TICKER.

How It Works

graph TD
  A[Client Connects] --> B[Set Event Stream]
  B --> C{Send Events}
  C -->|Ticker| D[Send JSON Event]
  C -->|Keep-Alive| E[Send Comment]
  C -->|Client Disconnect| F[Close Stream]
  D --> C
  E --> C

SSE Endpoint

Connect to /sse to receive JSON events.

• Endpoint: GET /sse
• Env: ECHO_SSE_TICKER=5s (default: 5s)
• Example:

curl -N http://localhost:8080/sse
# Response (stream):
# data: {"counter": 1, "timestamp": "2025-09-14T20:07:00Z"}
# data: {"counter": 2, "timestamp": "2025-09-14T20:07:05Z"}

SSE Tester

Access a browser-based tester at /web-sse to view streaming events.

• URL: http://localhost:8080/web-sse
• Features: Display events, monitor connection status.

Notes

• Keep-alive comments sent every 1s to maintain connection.
• No rate limiting applied to SSE (explicitly bypassed).
• Context cancellation closes stream on client disconnect.
• Events are not logged to avoid overhead.