Function start

web/src/llm-api/openrouter.ts:403–501

(controller)

  // Create a ReadableStream that Next.js can handle
  const stream = new ReadableStream({
    async start(controller) {
      const decoder = new TextDecoder()
      let buffer = ''

      // Send initial connection message
      controller.enqueue(
        new TextEncoder().encode(`: connected ${new Date().toISOString()}\n`),
      )

      // Start heartbeat
      heartbeatInterval = setInterval(() => {
        if (!clientDisconnected) {
          try {
            controller.enqueue(
              new TextEncoder().encode(
                `: heartbeat ${new Date().toISOString()}\n\n`,
              ),
            )
          } catch {
            // client disconnected, ignore error
          }
        }
      }, 30000)

      try {
        let done = false
        while (!done) {
          const result = await reader.read()
          done = result.done
          const value = result.value

          if (done) {
            break
          }

          buffer += decoder.decode(value, { stream: true })
          let lineEnd = buffer.indexOf('\n')

          while (lineEnd !== -1) {
            const line = buffer.slice(0, lineEnd + 1)
            buffer = buffer.slice(lineEnd + 1)

            const lineResult = await handleLine({
              userId,
              stripeCustomerId,
              agentId,
              clientId,
              clientRequestId,
              costMode,
              byok,
              startTime,
              request: auditRequest,
              line,
              state,
              logger,
              insertMessage: insertMessageBigquery,
            })
            state = lineResult.state