TanStack
Function References

toServerSentEventsStream

Function: toServerSentEventsStream()

ts
function toServerSentEventsStream(
   stream, 
   abortController?, 
getId?): ReadableStream<Uint8Array<ArrayBufferLike>>;

Defined in: packages/ai/src/stream-to-response.ts:260

Convert a StreamChunk async iterable to a ReadableStream in Server-Sent Events format

This creates a ReadableStream that emits chunks in SSE format:

  • Each chunk is prefixed with "data: "
  • Each chunk is followed by "\n\n"
  • Stream ends when the underlying iterable is exhausted (RUN_FINISHED is the terminal event)

Parameters

stream

AsyncIterable<AGUIEvent>

AsyncIterable of StreamChunks from chat()

abortController?

AbortController

Optional AbortController to abort when stream is cancelled

getId?

(chunk, index) => string | undefined

Optional per-chunk durability offset; when present, each event gets an id: line

Returns

ReadableStream<Uint8Array<ArrayBufferLike>>

ReadableStream in Server-Sent Events format