Shopify app proxy waits for res.end(), without respecting res.flushHeaders(), and res.write(). This disallows SSE.
Topic summary
A developer is encountering an issue with Shopify App Proxy’s handling of Server-Sent Events (SSE). The proxy appears to wait for the response to fully end (res.end()) before forwarding data, which prevents SSE from functioning properly. SSE requires streaming capabilities through methods like res.flushHeaders() and res.write() to send incremental updates to the client, but the Shopify proxy doesn’t respect these streaming operations. This limitation blocks real-time data transmission patterns that rely on keeping connections open and sending data progressively rather than all at once.