Consume
fetchSSE supports POST bodies, auth, abort, resume IDs, retry policy and three timeout phases.
Server-Sent Events, end to end
@stackline/sse
Parse, encode, reconnect and serve real-time streams with one zero-dependency package.
npm install @stackline/sse
Runs locally in this page
Stream lab
The parser receives this stream in incremental chunks.
No request leaves this page. The playground executes the package browser build directly.
One coherent contract
The full SSE lifecycle
Parse
createParser handles split UTF-8, CR, LF, CRLF, comments, retry fields and bounded buffers.
Encode
encodeSSE and encodeJSON prevent field injection and preserve multiline payloads.
Serve
eventStreamResponse and channels expose backpressure, heartbeats and correct HTTP headers.
AI streaming client
Async iteration, cancellation included
import { fetchSSE } from '@stackline/sse';
for await (const event of fetchSSE('/api/generate', {
method: 'POST',
body: JSON.stringify({ prompt: 'Hello', stream: true }),
idleTimeout: 45_000,
retry: { retries: 3 }
})) {
if (event.data === '[DONE]') break;
render(JSON.parse(event.data));
}Publish once, run broadly
Compatibility without baggage
BrowserESM + global bundleReady
Node.js14.17 through 24Ready
EdgeWorkers and Web StreamsReady
Deno / BunNative ESMReady
TypeScript3.9 through 7Ready
Bounded by default
- Line length
- 1 MiB
- Event size
- 1 MiB
- Queued events
- 4,096
- Feed slice
- 16 KiB
Oversized or malformed input fails with stable error codes instead of growing memory without a bound.
Start with one dependency
A smaller streaming stack.
ESM, CommonJS, browser bundle and declarations ship from the same tested artifact.