# http/sse-send
Send one Server-Sent Event on a stream. Multi-line data is split into one
`data:` line per line.
## Syntax
[http/sse-send $stream data ?opts]
## Parameters
- `$stream` — `%SseStream{}` from `http/sse`
- `$data` — event payload (string); trailing `\r` is trimmed per line
- `$opts` — optional map: `:event` name, `:id` id
## Examples
[http/sse-send $s "hello"] # → true [http/sse-send $s "line1\nline2" %{ :event "tick" :id "42" }] set r [http/sse-send $s "late"] # after close [err? $r] # → true
## Returns
`true`; `%Err{:message}` when the stream is closed, the first argument is
not a stream, `$data` is not a string, or the client is too slow (pending
output above 1 MiB — the stream is closed rather than buffering without
bound).
## See Also
`http/sse`, `http/sse-comment`, `http/sse-close`