Understand and count tokens

// Make sure to include these imports:
// import { GoogleGenerativeAI } from "@google/generative-ai";
const genAI = new GoogleGenerativeAI(process.env.API_KEY);
const model = genAI.getGenerativeModel({
  model: "gemini-1.5-flash",
});

// Count tokens in a prompt without calling text generation.
const countResult = await model.countTokens(
  "The quick brown fox jumps over the lazy dog.",
);

console.log(countResult.totalTokens); // 11

const generateResult = await model.generateContent(
  "The quick brown fox jumps over the lazy dog.",
);

// On the response for `generateContent`, use `usageMetadata`
// to get separate input and output token counts
// (`promptTokenCount` and `candidatesTokenCount`, respectively),
// as well as the combined token count (`totalTokenCount`).
console.log(generateResult.response.usageMetadata);
// candidatesTokenCount and totalTokenCount depend on response, may vary
// { promptTokenCount: 11, candidatesTokenCount: 124, totalTokenCount: 135 }
count_tokens.js

// Make sure to include these imports:
// import { GoogleGenerativeAI } from "@google/generative-ai";
const genAI = new GoogleGenerativeAI(process.env.API_KEY);
const model = genAI.getGenerativeModel({
  model: "gemini-1.5-flash",
});

const chat = model.startChat({
  history: [
    {
      role: "user",
      parts: [{ text: "Hi my name is Bob" }],
    },
    {
      role: "model",
      parts: [{ text: "Hi Bob!" }],
    },
  ],
});

const countResult = await model.countTokens({
  generateContentRequest: { contents: await chat.getHistory() },
});
console.log(countResult.totalTokens); // 10

const chatResult = await chat.sendMessage(
  "In one sentence, explain how a computer works to a young child.",
);

// On the response for `sendMessage`, use `usageMetadata`
// to get separate input and output token counts
// (`promptTokenCount` and `candidatesTokenCount`, respectively),
// as well as the combined token count (`totalTokenCount`).
console.log(chatResult.response.usageMetadata);
// candidatesTokenCount and totalTokenCount depend on response, may vary
// { promptTokenCount: 25, candidatesTokenCount: 25, totalTokenCount: 50 }
count_tokens.js

// Make sure to include these imports:
// import { GoogleAIFileManager } from "@google/generative-ai/server";
// import { GoogleGenerativeAI } from "@google/generative-ai";
const fileManager = new GoogleAIFileManager(process.env.API_KEY);

const uploadResult = await fileManager.uploadFile(
  `${mediaPath}/jetpack.jpg`,
  { mimeType: "image/jpeg" },
);

const imagePart = {
  fileData: {
    fileUri: uploadResult.file.uri,
    mimeType: uploadResult.file.mimeType,
  },
};

const genAI = new GoogleGenerativeAI(process.env.API_KEY);
const model = genAI.getGenerativeModel({
  model: "gemini-1.5-flash",
});

const prompt = "Tell me about this image.";

// Call `countTokens` to get the input token count
// of the combined text and file (`totalTokens`).
// An image's display or file size does not affect its token count.
// Optionally, you can call `countTokens` for the text and file separately.
const countResult = await model.countTokens([prompt, imagePart]);

console.log(countResult.totalTokens); // 265

const generateResult = await model.generateContent([prompt, imagePart]);

// On the response for `generateContent`, use `usageMetadata`
// to get separate input and output token counts
// (`promptTokenCount` and `candidatesTokenCount`, respectively),
// as well as the combined token count (`totalTokenCount`).
console.log(generateResult.response.usageMetadata);
// candidatesTokenCount and totalTokenCount depend on response, may vary
// { promptTokenCount: 265, candidatesTokenCount: 157, totalTokenCount: 422 }
count_tokens.js

// Make sure to include these imports:
// import { GoogleGenerativeAI } from "@google/generative-ai";
const genAI = new GoogleGenerativeAI(process.env.API_KEY);
const model = genAI.getGenerativeModel({
  model: "gemini-1.5-flash",
});

function fileToGenerativePart(path, mimeType) {
  return {
    inlineData: {
      data: Buffer.from(fs.readFileSync(path)).toString("base64"),
      mimeType,
    },
  };
}

const imagePart = fileToGenerativePart(
  `${mediaPath}/jetpack.jpg`,
  "image/jpeg",
);

const prompt = "Tell me about this image.";

// Call `countTokens` to get the input token count
// of the combined text and file (`totalTokens`).
// An image's display or file size does not affect its token count.
// Optionally, you can call `countTokens` for the text and file separately.
const countResult = await model.countTokens([prompt, imagePart]);
console.log(countResult.totalTokens); // 265

const generateResult = await model.generateContent([prompt, imagePart]);

// On the response for `generateContent`, use `usageMetadata`
// to get separate input and output token counts
// (`promptTokenCount` and `candidatesTokenCount`, respectively),
// as well as the combined token count (`totalTokenCount`).
console.log(generateResult.response.usageMetadata);
// candidatesTokenCount and totalTokenCount depend on response, may vary
// { promptTokenCount: 265, candidatesTokenCount: 157, totalTokenCount: 422 }
count_tokens.js

// Make sure to include these imports:
// import { GoogleAIFileManager, FileState } from "@google/generative-ai/server";
// import { GoogleGenerativeAI } from "@google/generative-ai";
const fileManager = new GoogleAIFileManager(process.env.API_KEY);

const uploadVideoResult = await fileManager.uploadFile(
  `${mediaPath}/Big_Buck_Bunny.mp4`,
  { mimeType: "video/mp4" },
);

let file = await fileManager.getFile(uploadVideoResult.file.name);
process.stdout.write("processing video");
while (file.state === FileState.PROCESSING) {
  process.stdout.write(".");
  // Sleep for 10 seconds
  await new Promise((resolve) => setTimeout(resolve, 10_000));
  // Fetch the file from the API again
  file = await fileManager.getFile(uploadVideoResult.file.name);
}

if (file.state === FileState.FAILED) {
  throw new Error("Video processing failed.");
} else {
  process.stdout.write("\n");
}

const videoPart = {
  fileData: {
    fileUri: uploadVideoResult.file.uri,
    mimeType: uploadVideoResult.file.mimeType,
  },
};

const genAI = new GoogleGenerativeAI(process.env.API_KEY);
const model = genAI.getGenerativeModel({
  model: "gemini-1.5-flash",
});

const prompt = "Tell me about this video.";

// Call `countTokens` to get the input token count
// of the combined text and file (`totalTokens`).
// A video or audio file is converted to tokens at a fixed rate of tokens
// per second.
// Optionally, you can call `countTokens` for the text and file separately.
const countResult = await model.countTokens([prompt, videoPart]);

console.log(countResult.totalTokens); // 302

const generateResult = await model.generateContent([prompt, videoPart]);

// On the response for `generateContent`, use `usageMetadata`
// to get separate input and output token counts
// (`promptTokenCount` and `candidatesTokenCount`, respectively),
// as well as the combined token count (`totalTokenCount`).
console.log(generateResult.response.usageMetadata);
// candidatesTokenCount and totalTokenCount depend on response, may vary
// { promptTokenCount: 302, candidatesTokenCount: 46, totalTokenCount: 348 }
count_tokens.js

// Make sure to include these imports:
// import { GoogleGenerativeAI } from "@google/generative-ai";
const genAI = new GoogleGenerativeAI(process.env.API_KEY);
const prompt = "The quick brown fox jumps over the lazy dog.";
const modelNoInstructions = genAI.getGenerativeModel({
  model: "models/gemini-1.5-flash",
});

const resultNoInstructions = await modelNoInstructions.countTokens(prompt);

console.log(resultNoInstructions);
// { totalTokens: 11 }

const modelWithInstructions = genAI.getGenerativeModel({
  model: "models/gemini-1.5-flash",
  systemInstruction: "You are a cat. Your name is Neko.",
});

const resultWithInstructions =
  await modelWithInstructions.countTokens(prompt);

// The total token count includes everything sent to the
// generateContent() request. When you use system instructions, the
// total token count increases.
console.log(resultWithInstructions);
// { totalTokens: 23 }
count_tokens.js

// Make sure to include these imports:
// import { GoogleGenerativeAI } from "@google/generative-ai";
const genAI = new GoogleGenerativeAI(process.env.API_KEY);
const prompt =
  "I have 57 cats, each owns 44 mittens, how many mittens is that in total?";

const modelNoTools = genAI.getGenerativeModel({
  model: "models/gemini-1.5-flash",
});

const resultNoTools = await modelNoTools.countTokens(prompt);

console.log(resultNoTools);
// { totalTokens: 23 }

const functionDeclarations = [
  { name: "add" },
  { name: "subtract" },
  { name: "multiply" },
  { name: "divide" },
];

const modelWithTools = genAI.getGenerativeModel({
  model: "models/gemini-1.5-flash",
  tools: [{ functionDeclarations }],
});

const resultWithTools = await modelWithTools.countTokens(prompt);

// The total token count includes everything sent to the
// generateContent() request. When you use tools (like function calling),
// the total token count increases.
console.log(resultWithTools);
// { totalTokens: 99 }
count_tokens.js