generative-ai/snippets/gemini-system-instruction.js

// Copyright 2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// [START generativeaionvertexai_gemini_system_instruction]
const {VertexAI} = require('@google-cloud/vertexai');

/**
 * TODO(developer): Update these variables before running the sample.
 */
async function set_system_instruction(projectId = 'PROJECT_ID') {
  const vertexAI = new VertexAI({project: projectId, location: 'us-central1'});

  const generativeModel = vertexAI.getGenerativeModel({
    model: 'gemini-2.0-flash-001',
    systemInstruction: {
      parts: [
        {text: 'You are a helpful language translator.'},
        {text: 'Your mission is to translate text in English to French.'},
      ],
    },
  });

  const textPart = {
    text: `
    User input: I like bagels.
    Answer:`,
  };

  const request = {
    contents: [{role: 'user', parts: [textPart]}],
  };

  const resp = await generativeModel.generateContent(request);
  const contentResponse = await resp.response;
  console.log(JSON.stringify(contentResponse));
}
// [END generativeaionvertexai_gemini_system_instruction]

set_system_instruction(...process.argv.slice(2)).catch(err => {
  console.error(err.message);
  process.exitCode = 1;
});