toHttpStream

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

Defined in: packages/ai/src/stream-to-response.ts:1416

Convert a StreamChunk async iterable to a ReadableStream in HTTP stream format (newline-delimited JSON)

This creates a ReadableStream that emits chunks as newline-delimited JSON:

• Each chunk is JSON.stringify'd and followed by "\n"
• No SSE formatting (no "data: " prefix)

This format is compatible with fetchHttpStream connection adapter.

When getId is supplied (delivery durability), each chunk is emitted as an envelope {"id":"<offset>","chunk":{…}} instead of a bare chunk. NDJSON has no native event-id field like SSE's id: line, so the resumable offset rides inside the payload. Untagged chunks (no id) stay bare, so a non-durable stream is byte-identical to before and the client auto-detects either form.

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, chunks are envelope-encoded

Returns#

ReadableStream<Uint8Array<ArrayBufferLike>>

ReadableStream in HTTP stream format (newline-delimited JSON)

Example#

const stream = chat({ adapter: openaiText('gpt-5.5'), messages: [...] });
const readableStream = toHttpStream(stream);
// Use with Response for HTTP streaming (not SSE)
return new Response(readableStream, {
  headers: { 'Content-Type': 'application/x-ndjson' }
});