Function start

apps/sim/app/api/wand/route.ts:384–538

(controller)

        const readable = new ReadableStream({
          async start(controller) {
            const reader = response.body?.getReader()
            if (!reader) {
              controller.close()
              return
            }

            let finalUsage: any = null
            let usageRecorded = false

            const flushUsage = async () => {
              if (usageRecorded || !finalUsage) {
                return
              }

              usageRecorded = true
              await updateUserStatsForWand(
                billingUserId,
                workspaceId,
                finalUsage,
                requestId,
                isBYOK
              )
            }

            try {
              let buffer = ''
              let chunkCount = 0
              let activeEventType: string | undefined

              while (true) {
                const { done, value } = await reader.read()

                if (done) {
                  logger.info(`[${requestId}] Stream completed. Total chunks: ${chunkCount}`)
                  await flushUsage()
                  controller.enqueue(encoder.encode(`data: ${JSON.stringify({ done: true })}\n\n`))
                  controller.close()
                  break
                }

                buffer += decoder.decode(value, { stream: true })

                const lines = buffer.split('\n')
                buffer = lines.pop() || ''

                for (const line of lines) {
                  const trimmed = line.trim()
                  if (!trimmed) {
                    continue
                  }

                  if (trimmed.startsWith('event:')) {
                    activeEventType = trimmed.slice(6).trim()
                    continue
                  }

                  if (!trimmed.startsWith('data:')) {