Gemini API Stream with Tool Calling (file_search): Bot only responds to the first message, then stops processing stream

[mysubcult]

Hello Remi,

I'm integrating the Google Gemini streaming API (streamGenerateContent?alt=sse) and have encountered a specific behavior I'm not sure how to handle correctly within LHC.

The Problem:

The integration works perfectly for simple text responses. However, when Gemini uses its native file_search tool, the bot fails to display the final answer.

Through cURL debugging, I've discovered that when file_search is used, the Gemini stream response is structured as follows:

1. The very first JSON object in the stream contains a functionCall event (e.g., {"functionCall": {"name": "google:file_search", ...}}).
2. Immediately following in the same stream, Gemini sends subsequent JSON objects that contain the actual text chunks of the final answer (e.g., {"text": "You can download..."}).

The issue seems to be that LHC correctly identifies the initial functionCall event but then appears to stop processing the stream. It doesn't read the subsequent text parts that arrive right after, so the user never sees the final message.

My Core Question:

My request body and tools configuration seem correct, as Gemini does attempt to use the tool. The issue appears to be in parsing this specific stream structure.

What is the recommended way to configure LHC to correctly handle a single stream that begins with a functionCall event and is immediately followed by the text content of the message? Is this a known behavior that requires a specific setup in the REST API output definitions or Bot Triggers?

I'm trying to understand if I'm missing a configuration step or if the stream parser isn't expecting this sequence of events from an API.

For your reference, I've attached my REST API and Bot configurations, plus the full cURL log that clearly shows the functionCall event followed by the text events in the same stream.

Thank you for your expertise and guidance.

Here is the JSON body I am using for the REST API call:

{
  "system_instruction": {
    "parts": [
      {
        "text": "Ты — Смарти, AI-ассистент техподдержки. Твоя задача — отвечать на вопросы, используя поиск по базе знаний, или вызывать функции, если этого требует ситуация.\n\n- Для ответов на вопросы по продуктам, ошибкам и инструкциям используй поиск по базе знаний (`file_search`).\n- Если пользователь прямо просит связать с оператором, купить что-то или активировать устройство, используй функции `call_operator`, `call_sales` или `activate_device`.\n- Если после двух неудачных поисков в базе знаний ты не нашел ответ, молча вызови `call_operator`.\n- Если запрос пользователя неясен или это приветствие, просто ответь текстом."
      }
    ]
  },
  "contents": [
    {if_previous_visitor_messages_list}
    {previous_visitor_messages_list_url__30__0}
    {skip_empty_msg}
    {separator},{/separator}
    {
      "role": "{assistant}model{/assistant}{user}user{/user}",
      "parts": [{
        "text": {not_item_empty__args.item.msg}{{args.item.msg}}{/not_item_empty}
      }]
    }
    {/previous_visitor_messages_list_url}
    {/if_previous_visitor_messages_list}
  ],
  "generationConfig": {
    "maxOutputTokens": 3000,
    "temperature": 0.5
  },
  "tools": [
    {
      "functionDeclarations": [
        {
          "name": "call_operator",
          "description": "Вызвать, если пользователь просит оператора ИЛИ после двух неудачных поисков."
        },
        {
          "name": "activate_device",
          "description": "Вызвать при прямом требовании пользователя НАЧАТЬ активацию."
        },
        {
          "name": "call_sales",
          "description": "Вызвать, если пользователь явно хочет купить/продлить подписку."
        }
      ]
    },
    {
      "file_search": {
        "file_search_store_names": [
          "fileSearchStores/smartdiag-knowledge-base-ct077nqm6qu6"
        ]
      }
    }
  ]
}

I have attached my exported Bot and REST API configurations, along with a detailed cURL log showing the full stream response from Gemini for the failing request. The log clearly shows the functionCall event followed by the text content events that are currently being ignored.

Thank you for your guidance on how to configure LHC to handle this specific streaming behavior.

rest-api-55.json
lhc-bot-83.json

Click to view the full cURL log for the failing request

curl -X POST 'https://generativelanguage.googleapis.com/v1beta/models/gemini-flash-latest:streamGenerateContent?alt=sse&key=AIzaSyBsnjd3WLrG8zQ8c-kCJNthA2lj9LKzMhM' \ -H 'Content-Type: a...' --data-binary @- << 'CURL_DATA_EOF' { "system_instruction": { "parts": [ { "text": "\u0422\u044b \u2014 \u0421\u043c\u0430\u0440\u0442\u0438, AI-\u0430\u0441\u0441\u0438\u0441\u0442\u0435\u043d\u0442 \u0442\u0435\u0445\u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0438. \u0422\u0432\u043e\u044f \u0437\u0430\u0434\u0430\u0447\u0430 \u2014 \u043e\u0442\u0432\u0435\u0447\u0430\u0442\u044c \u043d\u0430 \u0432\u043e\u043f\u0440\u043e\u0441\u044b, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u044f \u043f\u043e\u0438\u0441\u043a \u043f\u043e \u0431\u0430\u0437\u0435 \u0437\u043d\u0430\u043d\u0438\u0439, \u0438\u043b\u0438 \u0432\u044b\u0437\u044b\u0432\u0430\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438, \u0435\u0441\u043b\u0438 \u044d\u0442\u043e\u0433\u043e \u0442\u0440\u0435\u0431\u0443\u0435\u0442 \u0441\u0438\u0442\u0443\u0430\u0446\u0438\u044f.\n\n- \u0414\u043b\u044f \u043e\u0442\u0432\u0435\u0442\u043e\u0432 \u043d\u0430 \u0432\u043e\u043f\u0440\u043e\u0441\u044b \u043f\u043e \u043f\u0440\u043e\u0434\u0443\u043a\u0442\u0430\u043c, \u043e\u0448\u0438\u0431\u043a\u0430\u043c \u0438 \u0438\u043d\u0441\u0442\u0440\u0443\u043a\u0446\u0438\u044f\u043c \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0439 \u043f\u043e\u0438\u0441\u043a \u043f\u043e \u0431\u0430\u0437\u0435 \u0437\u043d\u0430\u043d\u0438\u0439 (`file_search`).\n- \u0415\u0441\u043b\u0438 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044c \u043f\u0440\u044f\u043c\u043e \u043f\u0440\u043e\u0441\u0438\u0442 \u0441\u0432\u044f\u0437\u0430\u0442\u044c \u0441 \u043e\u043f\u0435\u0440\u0430\u0442\u043e\u0440\u043e\u043c, \u043a\u0443\u043f\u0438\u0442\u044c \u0447\u0442\u043e-\u0442\u043e \u0438\u043b\u0438 \u0430\u043a\u0442\u0438\u0432\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u0443\u0441\u0442\u0440\u043e\u0439\u0441\u0442\u0432\u043e, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0439 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 `call_operator`, `call_sales` \u0438\u043b\u0438 `activate_device`.\n- \u0415\u0441\u043b\u0438 \u043f\u043e\u0441\u043b\u0435 \u0434\u0432\u0443\u0445 \u043d\u0435\u0443\u0434\u0430\u0447\u043d\u044b\u0445 \u043f\u043e\u0438\u0441\u043a\u043e\u0432 \u0432 \u0431\u0430\u0437\u0435 \u0437\u043d\u0430\u043d\u0438\u0439 \u0442\u044b \u043d\u0435 \u043d\u0430\u0448\u0435\u043b \u043e\u0442\u0432\u0435\u0442, \u043c\u043e\u043b\u0447\u0430 \u0432\u044b\u0437\u043e\u0432\u0438 `call_operator`.\n- \u0415\u0441\u043b\u0438 \u0437\u0430\u043f\u0440\u043e\u0441 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f \u043d\u0435\u044f\u0441\u0435\u043d \u0438\u043b\u0438 \u044d\u0442\u043e \u043f\u0440\u0438\u0432\u0435\u0442\u0441\u0442\u0432\u0438\u0435, \u043f\u0440\u043e\u0441\u0442\u043e \u043e\u0442\u0432\u0435\u0442\u044c \u0442\u0435\u043a\u0441\u0442\u043e\u043c." } ] }, "contents": [ { "role": "user", "parts": [ { "text": "\u0439\u043e" } ] }, { "role": "model", "parts": [ { "text": "\u041f\u0440\u0438\u0432\u0435\u0442! \u0427\u0435\u043c \u043c\u043e\u0433\u0443 \u043f\u043e\u043c\u043e\u0447\u044c?" } ] }, { "role": "user", "parts": [ { "text": "\u0433\u0434\u0435 \u0441\u043a\u0430\u0447\u0430\u0442\u044c \u0432\u0430\u0441\u044e?" } ] }, { "role": "model", "parts": [ { "text": "\u041f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0435 \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u0435 **\"\u0412\u0430\u0441\u044f\"** (\u043a\u043e\u0442\u043e\u0440\u043e\u0435 \u0442\u0430\u043a\u0436\u0435 \u0438\u0437\u0432\u0435\u0441\u0442\u043d\u043e \u043a\u0430\u043a VCDS) \u043c\u043e\u0436\u043d\u043e \u0441\u043a\u0430\u0447\u0430\u0442\u044c \u043d\u0430 \u043e\u0444\u0438\u0446\u0438\u0430\u043b\u044c\u043d\u043e\u043c \u0441\u0430\u0439\u0442\u0435.\n\n\u0412\u043e\u0442 \u043f\u043e\u0448\u0430\u0433\u043e\u0432\u0430\u044f \u0438\u043d\u0441\u0442\u0440\u0443\u043a\u0446\u0438\u044f:\n\n1. \u041f\u0435\u0440\u0435\u0439\u0434\u0438\u0442\u0435 \u043d\u0430 \u043d\u0430\u0448 **\u0441\u0430\u0439\u0442**.\n2. \u0412 \u0433\u043b\u0430\u0432\u043d\u043e\u043c \u043c\u0435\u043d\u044e \u043d\u0430\u0439\u0434\u0438\u0442\u0435 \u0438 \u0432\u044b\u0431\u0435\u0440\u0438\u0442\u0435 \u0440\u0430\u0437\u0434\u0435\u043b **\"\u041f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u044b\"**.\n3. \u0412 \u0441\u043f\u0438\u0441\u043a\u0435 \u043a\u0430\u0442\u0435\u0433\u043e\u0440\u0438\u0439 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u0432\u044b\u0431\u0435\u0440\u0438\u0442\u0435 **\"\u041c\u0430\u0440\u043e\u0447\u043d\u044b\u0435\"**.\n4. \u041d\u0430\u0439\u0434\u0438\u0442\u0435 **\"VCDS\/\u0412\u0430\u0441\u044f\"** \u0432 \u043f\u0440\u0435\u0434\u043b\u043e\u0436\u0435\u043d\u043d\u043e\u043c \u0441\u043f\u0438\u0441\u043a\u0435 \u0438 \u043d\u0430\u0436\u043c\u0438\u0442\u0435 \u043a\u043d\u043e\u043f\u043a\u0443 **\"\u0421\u043a\u0430\u0447\u0430\u0442\u044c\"** .\n\n**\u0412\u0430\u0436\u043d\u043e:** \u041f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0430 \"\u0412\u0430\u0441\u044f\" \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u0430\u043d\u0430 \u0442\u043e\u043b\u044c\u043a\u043e \u0434\u043b\u044f \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b **Windows**. \u0412\u0435\u0440\u0441\u0438\u0439 \u0434\u043b\u044f Android \u0438\u043b\u0438 iPhone \u043d\u0435 \u0441\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u0435\u0442 .\n\n\u0422\u0430\u043a\u0436\u0435 **\u043d\u0430\u0441\u0442\u043e\u044f\u0442\u0435\u043b\u044c\u043d\u043e \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0443\u0435\u043c** \u043f\u0435\u0440\u0435\u0434 \u0443\u0441\u0442\u0430\u043d\u043e\u0432\u043a\u043e\u0439 \u0432\u0440\u0435\u043c\u0435\u043d\u043d\u043e \u043e\u0442\u043a\u043b\u044e\u0447\u0438\u0442\u044c \u0430\u043d\u0442\u0438\u0432\u0438\u0440\u0443\u0441 \u0438 \u0431\u0440\u0430\u043d\u0434\u043c\u0430\u0443\u044d\u0440, \u0442\u0430\u043a \u043a\u0430\u043a \u043e\u043d\u0438 \u043c\u043e\u0433\u0443\u0442 \u043e\u0448\u0438\u0431\u043e\u0447\u043d\u043e \u0437\u0430\u0431\u043b\u043e\u043a\u0438\u0440\u043e\u0432\u0430\u0442\u044c \u0444\u0430\u0439\u043b\u044b \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u044b \u0438\u043b\u0438 \u0434\u0440\u0430\u0439\u0432\u0435\u0440\u043e\u0432 ." } ] }, { "role": "user", "parts": [ { "text": "\u0430 \u0430\u0432\u043a\u0442\u043e\u043e\u043c?" } ] } ], "generationConfig": { "maxOutputTokens": 3000, "temperature": 0.5 }, "tools": [ { "functionDeclarations": [ { "name": "call_operator", "description": "\u0412\u044b\u0437\u0432\u0430\u0442\u044c, \u0435\u0441\u043b\u0438 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044c \u043f\u0440\u043e\u0441\u0438\u0442 \u043e\u043f\u0435\u0440\u0430\u0442\u043e\u0440\u0430 \u0418\u041b\u0418 \u043f\u043e\u0441\u043b\u0435 \u0434\u0432\u0443\u0445 \u043d\u0435\u0443\u0434\u0430\u0447\u043d\u044b\u0445 \u043f\u043e\u0438\u0441\u043a\u043e\u0432." }, { "name": "activate_device", "description": "\u0412\u044b\u0437\u0432\u0430\u0442\u044c \u043f\u0440\u0438 \u043f\u0440\u044f\u043c\u043e\u043c \u0442\u0440\u0435\u0431\u043e\u0432\u0430\u043d\u0438\u0438 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f \u041d\u0410\u0427\u0410\u0422\u042c \u0430\u043a\u0442\u0438\u0432\u0430\u0446\u0438\u044e." }, { "name": "call_sales", "description": "\u0412\u044b\u0437\u0432\u0430\u0442\u044c, \u0435\u0441\u043b\u0438 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044c \u044f\u0432\u043d\u043e \u0445\u043e\u0447\u0435\u0442 \u043a\u0443\u043f\u0438\u0442\u044c\/\u043f\u0440\u043e\u0434\u043b\u0438\u0442\u044c \u043f\u043e\u0434\u043f\u0438\u0441\u043a\u0443." } ] }, { "file_search": { "file_search_store_names": [ "fileSearchStores\/smartdiag-knowledge-base-ct077nqm6qu6" ] } } ] } CURL_DATA_EOF

[mysubcult]

curl response.txt

[mysubcult]

I've made a few changes to output parsing, and everything seems to be working, can you tell me if I did everything right?

Before:

After:

[remdex]

If it works it's fine. You can always look
how open ai streaming was done.

And there was streaming example
so not sure what you are reinventing :)

https://doc.livehelperchat.com/docs/bot/gemini-integration

[mysubcult]

If it works it's fine. You can always look how open ai streaming was done.

And there was streaming example so not sure what you are reinventing :)

https://doc.livehelperchat.com/docs/bot/gemini-integration

Yes, of course, this is exactly the option I've used before, but I'm talking about the fact that now, as you know, it's possible to search through Gemini files inside their storage itself, and that's why I'm trying to implement it.

[remdex]

This should over all scearios
https://github.com/LiveHelperChat/gemini-rag