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A hapijs server sent event (SSE) example #4521
Description
Module version
21.3.10
What documentation problem did you notice?
There is no hapijs SSE example. I recently figured it out but don't know where to put it. So I have it here:
'use strict';
const Hapi = require('@hapi/hapi');
const init = async () => {
const server = Hapi.server({
port: 3000,
host: 'localhost'
});
// Route using raw.res for direct response handling
server.route({
method: 'GET',
path: '/sse',
handler: async (request, h) => {
const res = request.raw.res;
res.writeHead(200, { "Content-Type": "application/json" });
const intervalId = setInterval(() => {
res.write('this is a server sent event message');
}, 1000); // send a message every 1 second
const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));
await sleep(10000); // mock a long running request handling
res.end('This is a raw response using raw.res');
return h.abandon; // Abandon Hapi's normal response flow because we used raw response
}
});
await server.start();
console.log('Server running on %s', server.info.uri);
};
process.on('unhandledRejection', (err) => {
console.log(err);
process.exit(1);
});
init();
Activity
kanongil commentedon Aug 3, 2024
That is not really a SSE, as it needs to have
Content-Type: text/event-stream.Anyway, you should probably not use
raw.res, but rather return aPassthroughstream that you can keep and later write the event data to. The response won’t end until the stream is closed.Also, a
Cache-Control: no-cacheheader is probably appropriate.wy193777 commentedon Aug 5, 2024
what's the difference between explicitly using res.end() compare to return a PassThrough?
Marsup commentedon Aug 5, 2024
I just went through the code of susie, it seems pretty close to what kanongil has in mind. It's pretty old but I think it should be mostly functional even on today's hapi, you can always fork it if you find bugs.
8th-block commentedon Oct 18, 2024
So is there a way to do "text/event-stream" in hapi?
damusix commentedon Nov 18, 2024
@wy193777 @8th-block Check this out: https://matthewwid.github.io/better-sse/reference/recipes/#hapi
I haven't tried it, but I ran into it and asked the maintainer to add a Hapi example and he did. Perhaps it can fit your needs?
hashda04 commentedon Aug 19, 2025
Hi everyone ,
I noticed there’s some back-and-forth about adding a proper SSE example to the Hapi docs. I’d be happy to help put together a minimal, correct snippet (using text/event-stream, proper headers, and streams) if that would be useful. Could you confirm if a contribution like this would be welcome for the documentation?
Thanks!