@thraggs/godspeed-sse

Server-Sent Events (SSE) middleware for Godspeed.

Installation

bun add @thraggs/godspeed-sse

Usage

import { GodspeedClient } from '@thraggs/godspeed';
import { sse } from '@thraggs/godspeed-sse';

const client = new GodspeedClient({
  baseURL: 'https://api.example.com',
});

client.use(sse());

const response = await client.get('/events');

for await (const event of response.parsedBody) {
  console.log('Event:', event.event);
  console.log('Data:', event.data);
  console.log('ID:', event.id);
}

How It Works

The plugin intercepts responses with Content-Type: text/event-stream and transforms the raw byte stream into parsed SSE events. All other responses pass through untouched with zero overhead.

Performance

• Zero overhead for non-SSE responses: Single header lookup
• Single-pass parsing: Events emitted as soon as complete message detected
• Minimal buffering: Only incomplete events remain in buffer
• Stream-based: No memory accumulation for long-lived connections

API

sse()

Creates a middleware that intercepts SSE responses.

Returns: MiddlewareFn

Event Type:

interface SSEEvent {
  id?: string;
  event?: string;
  data: string;
  retry?: number;
}

The parsed event stream is available in response.parsedBody as an async iterable ReadableStream<SSEEvent>.

SSE Protocol Support

• id: - Event ID
• event: - Event type
• data: - Event data (supports multi-line)
• retry: - Reconnection time in milliseconds

License

MIT