Function startInner

apps/sim/app/api/copilot/chat/stream/route.ts:269–480

(controller: ReadableStreamDefaultController)

  })

  async function startInner(controller: ReadableStreamDefaultController) {
    let cursor = afterCursor || '0'
    let controllerClosed = false
    let sawTerminalEvent = false
    let currentRequestId = extractRunRequestId(run)
    let lastWriteTime = Date.now()
    // Stamp the logical request id + chat id on the resume root as soon
    // as we resolve them from the run row, so TraceQL joins work on
    // resume legs the same way they do on the original POST.
    if (currentRequestId) {
      rootSpan.setAttribute(TraceAttr.RequestId, currentRequestId)
      rootSpan.setAttribute(TraceAttr.SimRequestId, currentRequestId)
    }
    if (run?.chatId) {
      rootSpan.setAttribute(TraceAttr.ChatId, run.chatId)
    }

    const closeController = () => {
      if (controllerClosed) return
      controllerClosed = true
      try {
        controller.close()
      } catch {
        // Controller already closed by runtime/client
      }
    }

    const enqueueEvent = (payload: unknown) => {
      if (controllerClosed) return false
      try {
        controller.enqueue(encodeSSEEnvelope(payload))
        lastWriteTime = Date.now()
        return true
      } catch {
        controllerClosed = true
        return false
      }
    }

    const enqueueComment = (comment: string) => {
      if (controllerClosed) return false
      try {
        controller.enqueue(encodeSSEComment(comment))
        lastWriteTime = Date.now()
        return true
      } catch {
        controllerClosed = true
        return false
      }
    }

    const abortListener = () => {
      controllerClosed = true
    }
    request.signal.addEventListener('abort', abortListener, { once: true })

    const flushEvents = async () => {
      const events = await readEvents(streamId, cursor)