文字生成

Gemini API 可利用 Gemini 模型,根據各種輸入內容 (包括文字、圖片、影片和音訊) 產生文字輸出內容。

以下是採用單一文字輸入內容的基本範例:

from google import genai

client = genai.Client(api_key="GEMINI_API_KEY")

response = client.models.generate_content(
    model="gemini-2.0-flash",
    contents=["How does AI work?"]
)
print(response.text)
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "GEMINI_API_KEY" });

async function main() {
  const response = await ai.models.generateContent({
    model: "gemini-2.0-flash",
    contents: "How does AI work?",
  });
  console.log(response.text);
}

await main();
package main

import (
  "context"
  "fmt"
  "os"
  "google.golang.org/genai"
)

func main() {

  ctx := context.Background()
  client, _ := genai.NewClient(ctx, &genai.ClientConfig{
      APIKey:  os.Getenv("GEMINI_API_KEY"),
      Backend: genai.BackendGeminiAPI,
  })

  result, _ := client.Models.GenerateContent(
      ctx,
      "gemini-2.0-flash",
      genai.Text("Explain how AI works in a few words"),
      nil,
  )

  fmt.Println(result.Text())
}
curl "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=$GEMINI_API_KEY" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{
    "contents": [
      {
        "parts": [
          {
            "text": "How does AI work?"
          }
        ]
      }
    ]
  }'
// See https://developers.google.com/apps-script/guides/properties
// for instructions on how to set the API key.
const apiKey = PropertiesService.getScriptProperties().getProperty('GEMINI_API_KEY');

function main() {
  const payload = {
    contents: [
      {
        parts: [
          { text: 'How AI does work?' },
        ],
      },
    ],
  };

  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=${apiKey}`;
  const options = {
    method: 'POST',
    contentType: 'application/json',
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  const data = JSON.parse(response);
  const content = data['candidates'][0]['content']['parts'][0]['text'];
  console.log(content);
}

系統指令和設定

您可以透過系統指令引導 Gemini 模型的行為。如要這麼做,請傳遞 GenerateContentConfig 物件。

from google import genai
from google.genai import types

client = genai.Client(api_key="GEMINI_API_KEY")

response = client.models.generate_content(
    model="gemini-2.0-flash",
    config=types.GenerateContentConfig(
        system_instruction="You are a cat. Your name is Neko."),
    contents="Hello there"
)

print(response.text)
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "GEMINI_API_KEY" });

async function main() {
  const response = await ai.models.generateContent({
    model: "gemini-2.0-flash",
    contents: "Hello there",
    config: {
      systemInstruction: "You are a cat. Your name is Neko.",
    },
  });
  console.log(response.text);
}

await main();
package main

import (
  "context"
  "fmt"
  "os"
  "google.golang.org/genai"
)

func main() {

  ctx := context.Background()
  client, _ := genai.NewClient(ctx, &genai.ClientConfig{
      APIKey:  os.Getenv("GEMINI_API_KEY"),
      Backend: genai.BackendGeminiAPI,
  })

  config := &genai.GenerateContentConfig{
      SystemInstruction: genai.NewContentFromText("You are a cat. Your name is Neko.", genai.RoleUser),
  }

  result, _ := client.Models.GenerateContent(
      ctx,
      "gemini-2.0-flash",
      genai.Text("Hello there"),
      config,
  )

  fmt.Println(result.Text())
}
curl "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=$GEMINI_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "system_instruction": {
      "parts": [
        {
          "text": "You are a cat. Your name is Neko."
        }
      ]
    },
    "contents": [
      {
        "parts": [
          {
            "text": "Hello there"
          }
        ]
      }
    ]
  }'
// See https://developers.google.com/apps-script/guides/properties
// for instructions on how to set the API key.
const apiKey = PropertiesService.getScriptProperties().getProperty('GEMINI_API_KEY');

function main() {
  const systemInstruction = {
    parts: [{
      text: 'You are a cat. Your name is Neko.'
    }]
  };

  const payload = {
    systemInstruction,
    contents: [
      {
        parts: [
          { text: 'Hello there' },
        ],
      },
    ],
  };

  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=${apiKey}`;
  const options = {
    method: 'POST',
    contentType: 'application/json',
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  const data = JSON.parse(response);
  const content = data['candidates'][0]['content']['parts'][0]['text'];
  console.log(content);
}

GenerateContentConfig 物件還可讓您覆寫預設產生參數,例如溫度

from google import genai
from google.genai import types

client = genai.Client(api_key="GEMINI_API_KEY")

response = client.models.generate_content(
    model="gemini-2.0-flash",
    contents=["Explain how AI works"],
    config=types.GenerateContentConfig(
        max_output_tokens=500,
        temperature=0.1
    )
)
print(response.text)
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "GEMINI_API_KEY" });

async function main() {
  const response = await ai.models.generateContent({
    model: "gemini-2.0-flash",
    contents: "Explain how AI works",
    config: {
      maxOutputTokens: 500,
      temperature: 0.1,
    },
  });
  console.log(response.text);
}

await main();
package main

import (
  "context"
  "fmt"
  "os"
  "google.golang.org/genai"
)

func main() {

  ctx := context.Background()
  client, _ := genai.NewClient(ctx, &genai.ClientConfig{
    APIKey:  os.Getenv("GEMINI_API_KEY"),
    Backend: genai.BackendGeminiAPI,
  })

  temp := float32(0.9)
  topP := float32(0.5)
  topK := float32(20.0)
  maxOutputTokens := int32(100)

  config := &genai.GenerateContentConfig{
    Temperature:       &temp,
    TopP:              &topP,
    TopK:              &topK,
    MaxOutputTokens:   maxOutputTokens,
    ResponseMIMEType:  "application/json",
  }

  result, _ := client.Models.GenerateContent(
    ctx,
    "gemini-2.0-flash",
    genai.Text("What is the average size of a swallow?"),
    config,
  )

  fmt.Println(result.Text())
}
curl https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=$GEMINI_API_KEY \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{
    "contents": [
      {
        "parts": [
          {
            "text": "Explain how AI works"
          }
        ]
      }
    ],
    "generationConfig": {
      "stopSequences": [
        "Title"
      ],
      "temperature": 1.0,
      "maxOutputTokens": 800,
      "topP": 0.8,
      "topK": 10
    }
  }'
// See https://developers.google.com/apps-script/guides/properties
// for instructions on how to set the API key.
const apiKey = PropertiesService.getScriptProperties().getProperty('GEMINI_API_KEY');

function main() {
  const generationConfig = {
    temperature: 1,
    topP: 0.95,
    topK: 40,
    maxOutputTokens: 8192,
    responseMimeType: 'text/plain',
  };

  const payload = {
    generationConfig,
    contents: [
      {
        parts: [
          { text: 'Explain how AI works in a few words' },
        ],
      },
    ],
  };

  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=${apiKey}`;
  const options = {
    method: 'POST',
    contentType: 'application/json',
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  const data = JSON.parse(response);
  const content = data['candidates'][0]['content']['parts'][0]['text'];
  console.log(content);
}

如需可設定參數和其說明的完整清單,請參閱 API 參考資料中的 GenerateContentConfig

多模態輸入

Gemini API 支援多模態輸入內容,可讓您將文字與媒體檔案結合。以下範例說明如何提供圖片:

from PIL import Image
from google import genai

client = genai.Client(api_key="GEMINI_API_KEY")

image = Image.open("/path/to/organ.png")
response = client.models.generate_content(
    model="gemini-2.0-flash",
    contents=[image, "Tell me about this instrument"]
)
print(response.text)
import {
  GoogleGenAI,
  createUserContent,
  createPartFromUri,
} from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "GEMINI_API_KEY" });

async function main() {
  const image = await ai.files.upload({
    file: "/path/to/organ.png",
  });
  const response = await ai.models.generateContent({
    model: "gemini-2.0-flash",
    contents: [
      createUserContent([
        "Tell me about this instrument",
        createPartFromUri(image.uri, image.mimeType),
      ]),
    ],
  });
  console.log(response.text);
}

await main();
package main

import (
  "context"
  "fmt"
  "os"
  "google.golang.org/genai"
)

func main() {

  ctx := context.Background()
  client, _ := genai.NewClient(ctx, &genai.ClientConfig{
      APIKey:  os.Getenv("GEMINI_API_KEY"),
      Backend: genai.BackendGeminiAPI,
  })

  imagePath := "/path/to/organ.jpg"
  imgData, _ := os.ReadFile(imagePath)

  parts := []*genai.Part{
      genai.NewPartFromText("Tell me about this instrument"),
      &genai.Part{
          InlineData: &genai.Blob{
              MIMEType: "image/jpeg",
              Data:     imgData,
          },
      },
  }

  contents := []*genai.Content{
      genai.NewContentFromParts(parts, genai.RoleUser),
  }

  result, _ := client.Models.GenerateContent(
      ctx,
      "gemini-2.0-flash",
      contents,
      nil,
  )

  fmt.Println(result.Text())
}
# Use a temporary file to hold the base64 encoded image data
TEMP_B64=$(mktemp)
trap 'rm -f "$TEMP_B64"' EXIT
base64 $B64FLAGS $IMG_PATH > "$TEMP_B64"

# Use a temporary file to hold the JSON payload
TEMP_JSON=$(mktemp)
trap 'rm -f "$TEMP_JSON"' EXIT

cat > "$TEMP_JSON" << EOF
{
  "contents": [
    {
      "parts": [
        {
          "text": "Tell me about this instrument"
        },
        {
          "inline_data": {
            "mime_type": "image/jpeg",
            "data": "$(cat "$TEMP_B64")"
          }
        }
      ]
    }
  ]
}
EOF

curl "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=$GEMINI_API_KEY" \
  -H 'Content-Type: application/json' \
  -X POST \
  -d "@$TEMP_JSON"
// See https://developers.google.com/apps-script/guides/properties
// for instructions on how to set the API key.
const apiKey = PropertiesService.getScriptProperties().getProperty('GEMINI_API_KEY');

function main() {
  const imageUrl = 'http://image/url';
  const image = getImageData(imageUrl);
  const payload = {
    contents: [
      {
        parts: [
          { image },
          { text: 'Tell me about this instrument' },
        ],
      },
    ],
  };

  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=${apiKey}`;
  const options = {
    method: 'POST',
    contentType: 'application/json',
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  const data = JSON.parse(response);
  const content = data['candidates'][0]['content']['parts'][0]['text'];
  console.log(content);
}

function getImageData(url) {
  const blob = UrlFetchApp.fetch(url).getBlob();

  return {
    mimeType: blob.getContentType(),
    data: Utilities.base64Encode(blob.getBytes())
  };
}

如要瞭解提供圖片的其他方法,以及更進階的圖片處理作業,請參閱圖像理解指南。這個 API 也支援文件影片音訊輸入內容和理解。

串流回應

根據預設,模型只會在整個生成程序完成後傳回回覆。

如要提供更流暢的互動體驗,請使用串流功能,逐步接收 GenerateContentResponse 例項。

from google import genai

client = genai.Client(api_key="GEMINI_API_KEY")

response = client.models.generate_content_stream(
    model="gemini-2.0-flash",
    contents=["Explain how AI works"]
)
for chunk in response:
    print(chunk.text, end="")
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "GEMINI_API_KEY" });

async function main() {
  const response = await ai.models.generateContentStream({
    model: "gemini-2.0-flash",
    contents: "Explain how AI works",
  });

  for await (const chunk of response) {
    console.log(chunk.text);
  }
}

await main();
package main

import (
  "context"
  "fmt"
  "os"
  "google.golang.org/genai"
)

func main() {

  ctx := context.Background()
  client, _ := genai.NewClient(ctx, &genai.ClientConfig{
      APIKey:  os.Getenv("GEMINI_API_KEY"),
      Backend: genai.BackendGeminiAPI,
  })

  stream := client.Models.GenerateContentStream(
      ctx,
      "gemini-2.0-flash",
      genai.Text("Write a story about a magic backpack."),
      nil,
  )

  for chunk, _ := range stream {
      part := chunk.Candidates[0].Content.Parts[0]
      fmt.Print(part.Text)
  }
}
curl "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:streamGenerateContent?alt=sse&key=${GEMINI_API_KEY}" \
  -H 'Content-Type: application/json' \
  --no-buffer \
  -d '{
    "contents": [
      {
        "parts": [
          {
            "text": "Explain how AI works"
          }
        ]
      }
    ]
  }'
// See https://developers.google.com/apps-script/guides/properties
// for instructions on how to set the API key.
const apiKey = PropertiesService.getScriptProperties().getProperty('GEMINI_API_KEY');

function main() {
  const payload = {
    contents: [
      {
        parts: [
          { text: 'Explain how AI works' },
        ],
      },
    ],
  };

  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:streamGenerateContent?key=${apiKey}`;
  const options = {
    method: 'POST',
    contentType: 'application/json',
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  const data = JSON.parse(response);
  const content = data['candidates'][0]['content']['parts'][0]['text'];
  console.log(content);
}

多輪對話 (聊天)

我們的 SDK 提供功能,可將多輪提示和回覆收集到聊天中,讓您輕鬆追蹤對話記錄。

from google import genai

client = genai.Client(api_key="GEMINI_API_KEY")
chat = client.chats.create(model="gemini-2.0-flash")

response = chat.send_message("I have 2 dogs in my house.")
print(response.text)

response = chat.send_message("How many paws are in my house?")
print(response.text)

for message in chat.get_history():
    print(f'role - {message.role}',end=": ")
    print(message.parts[0].text)
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "GEMINI_API_KEY" });

async function main() {
  const chat = ai.chats.create({
    model: "gemini-2.0-flash",
    history: [
      {
        role: "user",
        parts: [{ text: "Hello" }],
      },
      {
        role: "model",
        parts: [{ text: "Great to meet you. What would you like to know?" }],
      },
    ],
  });

  const response1 = await chat.sendMessage({
    message: "I have 2 dogs in my house.",
  });
  console.log("Chat response 1:", response1.text);

  const response2 = await chat.sendMessage({
    message: "How many paws are in my house?",
  });
  console.log("Chat response 2:", response2.text);
}

await main();
package main

import (
  "context"
  "fmt"
  "os"
  "google.golang.org/genai"
)

func main() {

  ctx := context.Background()
  client, _ := genai.NewClient(ctx, &genai.ClientConfig{
      APIKey:  os.Getenv("GEMINI_API_KEY"),
      Backend: genai.BackendGeminiAPI,
  })

  history := []*genai.Content{
      genai.NewContentFromText("Hi nice to meet you! I have 2 dogs in my house.", genai.RoleUser),
      genai.NewContentFromText("Great to meet you. What would you like to know?", genai.RoleModel),
  }

  chat, _ := client.Chats.Create(ctx, "gemini-2.0-flash", nil, history)
  res, _ := chat.SendMessage(ctx, genai.Part{Text: "How many paws are in my house?"})

  if len(res.Candidates) > 0 {
      fmt.Println(res.Candidates[0].Content.Parts[0].Text)
  }
}
curl https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=$GEMINI_API_KEY \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "Hello"
          }
        ]
      },
      {
        "role": "model",
        "parts": [
          {
            "text": "Great to meet you. What would you like to know?"
          }
        ]
      },
      {
        "role": "user",
        "parts": [
          {
            "text": "I have two dogs in my house. How many paws are in my house?"
          }
        ]
      }
    ]
  }'
// See https://developers.google.com/apps-script/guides/properties
// for instructions on how to set the API key.
const apiKey = PropertiesService.getScriptProperties().getProperty('GEMINI_API_KEY');

function main() {
  const payload = {
    contents: [
      {
        role: 'user',
        parts: [
          { text: 'Hello' },
        ],
      },
      {
        role: 'model',
        parts: [
          { text: 'Great to meet you. What would you like to know?' },
        ],
      },
      {
        role: 'user',
        parts: [
          { text: 'I have two dogs in my house. How many paws are in my house?' },
        ],
      },
    ],
  };

  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=${apiKey}`;
  const options = {
    method: 'POST',
    contentType: 'application/json',
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  const data = JSON.parse(response);
  const content = data['candidates'][0]['content']['parts'][0]['text'];
  console.log(content);
}

也可以用於多輪對話。

from google import genai

client = genai.Client(api_key="GEMINI_API_KEY")
chat = client.chats.create(model="gemini-2.0-flash")

response = chat.send_message_stream("I have 2 dogs in my house.")
for chunk in response:
    print(chunk.text, end="")

response = chat.send_message_stream("How many paws are in my house?")
for chunk in response:
    print(chunk.text, end="")

for message in chat.get_history():
    print(f'role - {message.role}', end=": ")
    print(message.parts[0].text)
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: "GEMINI_API_KEY" });

async function main() {
  const chat = ai.chats.create({
    model: "gemini-2.0-flash",
    history: [
      {
        role: "user",
        parts: [{ text: "Hello" }],
      },
      {
        role: "model",
        parts: [{ text: "Great to meet you. What would you like to know?" }],
      },
    ],
  });

  const stream1 = await chat.sendMessageStream({
    message: "I have 2 dogs in my house.",
  });
  for await (const chunk of stream1) {
    console.log(chunk.text);
    console.log("_".repeat(80));
  }

  const stream2 = await chat.sendMessageStream({
    message: "How many paws are in my house?",
  });
  for await (const chunk of stream2) {
    console.log(chunk.text);
    console.log("_".repeat(80));
  }
}

await main();
package main

import (
  "context"
  "fmt"
  "os"
  "google.golang.org/genai"
)

func main() {

  ctx := context.Background()
  client, _ := genai.NewClient(ctx, &genai.ClientConfig{
      APIKey:  os.Getenv("GEMINI_API_KEY"),
      Backend: genai.BackendGeminiAPI,
  })

  history := []*genai.Content{
      genai.NewContentFromText("Hi nice to meet you! I have 2 dogs in my house.", genai.RoleUser),
      genai.NewContentFromText("Great to meet you. What would you like to know?", genai.RoleModel),
  }

  chat, _ := client.Chats.Create(ctx, "gemini-2.0-flash", nil, history)
  stream := chat.SendMessageStream(ctx, genai.Part{Text: "How many paws are in my house?"})

  for chunk, _ := range stream {
      part := chunk.Candidates[0].Content.Parts[0]
      fmt.Print(part.Text)
  }
}
curl https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:streamGenerateContent?alt=sse&key=$GEMINI_API_KEY \
  -H 'Content-Type: application/json' \
  -X POST \
  -d '{
    "contents": [
      {
        "role": "user",
        "parts": [
          {
            "text": "Hello"
          }
        ]
      },
      {
        "role": "model",
        "parts": [
          {
            "text": "Great to meet you. What would you like to know?"
          }
        ]
      },
      {
        "role": "user",
        "parts": [
          {
            "text": "I have two dogs in my house. How many paws are in my house?"
          }
        ]
      }
    ]
  }'
// See https://developers.google.com/apps-script/guides/properties
// for instructions on how to set the API key.
const apiKey = PropertiesService.getScriptProperties().getProperty('GEMINI_API_KEY');

function main() {
  const payload = {
    contents: [
      {
        role: 'user',
        parts: [
          { text: 'Hello' },
        ],
      },
      {
        role: 'model',
        parts: [
          { text: 'Great to meet you. What would you like to know?' },
        ],
      },
      {
        role: 'user',
        parts: [
          { text: 'I have two dogs in my house. How many paws are in my house?' },
        ],
      },
    ],
  };

  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:streamGenerateContent?key=${apiKey}`;
  const options = {
    method: 'POST',
    contentType: 'application/json',
    payload: JSON.stringify(payload)
  };

  const response = UrlFetchApp.fetch(url, options);
  const data = JSON.parse(response);
  const content = data['candidates'][0]['content']['parts'][0]['text'];
  console.log(content);
}

支援的模型

Gemini 系列的所有模型都支援文字生成功能。如要進一步瞭解模型及其功能,請參閱「模型」頁面。

最佳做法

提示訣竅

對於基本文字生成作業,只要使用零樣本提示,通常就足以產生結果,不需要範例、系統指示或特定格式。

如需更貼近需求的輸出內容:

  • 使用系統指示來引導模型。
  • 提供一些輸入和輸出範例,引導模型。這通常稱為「少量樣本」提示。
  • 考慮針對進階用途微調

如需更多提示,請參閱我們的提示工程指南

結構化輸出內容

在某些情況下,您可能需要結構化輸出內容,例如 JSON。詳情請參閱結構化輸出內容指南。

後續步驟