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Set system instructions to Multimodal AI Model
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This sample shows you how to set system instructions to a Multimodal AI Model
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For detailed documentation that includes this code sample, see the following:
Code sample
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[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],[],[],[],null,["# Set system instructions to Multimodal AI Model\n\nThis sample shows you how to set system instructions to a Multimodal AI Model\n\nExplore further\n---------------\n\n\nFor detailed documentation that includes this code sample, see the following:\n\n- [Use system instructions](/vertex-ai/generative-ai/docs/learn/prompts/system-instructions)\n\nCode sample\n-----------\n\n### Go\n\n\nBefore trying this sample, follow the Go setup instructions in the\n[Vertex AI quickstart using\nclient libraries](/vertex-ai/docs/start/client-libraries).\n\n\nFor more information, see the\n[Vertex AI Go API\nreference documentation](/go/docs/reference/cloud.google.com/go/aiplatform/latest/apiv1).\n\n\nTo authenticate to Vertex AI, set up Application Default Credentials.\nFor more information, see\n\n[Set up authentication for a local development environment](/docs/authentication/set-up-adc-local-dev-environment).\n\n import (\n \t\"context\"\n \t\"fmt\"\n \t\"io\"\n\n \tgenai \"google.golang.org/genai\"\n )\n\n // generateWithSystem shows how to generate text using a text prompt and system instruction.\n func generateWithSystem(w io.Writer) error {\n \tctx := context.Background()\n\n \tclient, err := genai.NewClient(ctx, &genai.ClientConfig{\n \t\tHTTPOptions: genai.HTTPOptions{APIVersion: \"v1\"},\n \t})\n \tif err != nil {\n \t\treturn fmt.Errorf(\"failed to create genai client: %w\", err)\n \t}\n\n \tmodelName := \"gemini-2.5-flash\"\n \tcontents := genai.Text(\"Why is the sky blue?\")\n \tconfig := &genai.GenerateContentConfig{\n \t\tSystemInstruction: &genai.Content{\n \t\t\tParts: []*genai.Part{\n \t\t\t\t{Text: \"You're a language translator. Your mission is to translate text in English to French.\"},\n \t\t\t},\n \t\t},\n \t}\n\n \tresp, err := client.Models.GenerateContent(ctx, modelName, contents, config)\n \tif err != nil {\n \t\treturn fmt.Errorf(\"failed to generate content: %w\", err)\n \t}\n\n \trespText := resp.Text()\n\n \tfmt.Fprintln(w, respText)\n\n \t// Example response:\n \t// Pourquoi le ciel est-il bleu ?\n\n \treturn nil\n }\n\n### Node.js\n\n\nBefore trying this sample, follow the Node.js setup instructions in the\n[Vertex AI quickstart using\nclient libraries](/vertex-ai/docs/start/client-libraries).\n\n\nFor more information, see the\n[Vertex AI Node.js API\nreference documentation](/nodejs/docs/reference/aiplatform/latest).\n\n\nTo authenticate to Vertex AI, set up Application Default Credentials.\nFor more information, see\n\n[Set up authentication for a local development environment](/docs/authentication/set-up-adc-local-dev-environment).\n\n const {GoogleGenAI} = require('@google/genai');\n\n const GOOGLE_CLOUD_PROJECT = process.env.GOOGLE_CLOUD_PROJECT;\n const GOOGLE_CLOUD_LOCATION = process.env.GOOGLE_CLOUD_LOCATION || 'global';\n\n async function generateContent(\n projectId = GOOGLE_CLOUD_PROJECT,\n location = GOOGLE_CLOUD_LOCATION\n ) {\n const ai = new GoogleGenAI({\n vertexai: true,\n project: projectId,\n location: location,\n });\n\n const prompt = `\n User input: I like bagels.\n Answer:\n `;\n\n const response = await ai.models.generateContent({\n model: 'gemini-2.5-flash',\n contents: prompt,\n config: {\n systemInstruction: [\n 'You are a language translator.',\n 'Your mission is to translate text in English to French.',\n ],\n },\n });\n\n console.log(response.text);\n\n return response.text;\n }\n\n### Python\n\n\nBefore trying this sample, follow the Python setup instructions in the\n[Vertex AI quickstart using\nclient libraries](/vertex-ai/docs/start/client-libraries).\n\n\nFor more information, see the\n[Vertex AI Python API\nreference documentation](/python/docs/reference/aiplatform/latest).\n\n\nTo authenticate to Vertex AI, set up Application Default Credentials.\nFor more information, see\n\n[Set up authentication for a local development environment](/docs/authentication/set-up-adc-local-dev-environment).\n\n from google import genai\n from google.genai.types import GenerateContentConfig, HttpOptions\n\n client = genai.Client(http_options=HttpOptions(api_version=\"v1\"))\n response = client.models.generate_content(\n model=\"gemini-2.5-flash\",\n contents=\"Why is the sky blue?\",\n config=GenerateContentConfig(\n system_instruction=[\n \"You're a language translator.\",\n \"Your mission is to translate text in English to French.\",\n ]\n ),\n )\n print(response.text)\n # Example response:\n # Pourquoi le ciel est-il bleu ?\n\nWhat's next\n-----------\n\n\nTo search and filter code samples for other Google Cloud products, see the\n[Google Cloud sample browser](/docs/samples?product=googlegenaisdk)."]]