Interactions API への移行

このガイドでは、generateContent API から Interactions API への移行について説明します。

Interactions API は、Gemini を使用して構築するための標準インターフェースです。エージェント ワークフロー、サーバーサイドの状態管理、複雑なマルチモーダル、マルチターンの会話に最適化されていますが、シンプルなステートレスのシングルターン リクエストも完全にサポートしています。generateContent は引き続き完全にサポートされますが、新規開発には Interactions API をおすすめします。

移行の理由

Interactions API を使用すると、Gemini を使用してより構造化された強力な方法で構築できます。

  • サーバーサイドの履歴管理: previous_interaction_id を使用してマルチターンのフローを簡素化します。サーバーはデフォルトで状態を有効にしますが（store=true）、store=false を設定してステートレス動作を選択することもできます。
  • 実行ステップのオブザーバビリティ: 型付きステップを使用すると、複雑なフローを簡単にデバッグし、中間イベント（思考や検索ウィジェットなど）の UI をレンダリングできます。
  • エージェント ワークフロー向けに構築: 型付き実行ステップを通じて、マルチステップ ツールの使用、オーケストレーション、複雑な推論フローをネイティブにサポートします。
  • 長時間実行タスクとバックグラウンド タスク: Deep Think や Deep Research などの時間のかかるオペレーションをバックグラウンド プロセスにオフロードできます。background=true
  • 新しいモデルと機能へのアクセス: 今後、コア メインライン ファミリー以外の新しいモデルと、新しいエージェント機能とツールは、Interactions API でのみリリースされます。既存のユースケースでは、generateContent は引き続き完全にサポートされます。

基本的な入出力

このセクションでは、シンプルなテキスト生成リクエストを移行する方法について説明します。

移行前（generateContent）

generateContent API はステートレスで、レスポンスを直接返します。レスポンス構造は、解析する parts のリストを含む content をそれぞれ含む candidates のリストで出力をラップします。

Python

from google import genai

client = genai.Client()

response = client.models.generate_content(
    model="gemini-2.5-flash", contents="Tell me a joke."
)
print(response.text)

JavaScript

import { GoogleGenAI } from '@google/genai';

const ai = new GoogleGenAI({});

const response = await ai.models.generateContent({
  model: "gemini-2.5-flash",
  contents: "Tell me a joke.",
});
console.log(response.text);

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [{
        "parts": [{
            "text": "Tell me a joke."
        }]
    }]
}'

# Response
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "text": "Why did the chicken cross the road? To get to the other side!"
          }
        ],
        "role": "model"
      },
      "finishReason": "STOP",
      "index": 0
    }
  ],
  "usageMetadata": {
    "promptTokenCount": 4,
    "candidatesTokenCount": 12,
    "totalTokenCount": 16
  }
}

移行後（Interactions API）

Interactions API は、steps タイムラインを含む保存されたインタラクション リソースを返します。候補とパーツをトラバースする代わりに、steps 配列を調べて目的の出力タイプを見つけます。

Python

from google import genai

client = genai.Client()

# The input can be a simple string shorthand
interaction = client.interactions.create(
    model="gemini-3-flash-preview", input="Tell me a joke."
)

# Inspect the steps manually
for step in interaction.steps:
    if step.type == "model_output":
        print(step.content[0].text)

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

let interaction = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: 'Tell me a joke.'
});

// Manual inspection
const modelStep = interaction.steps.find(s => s.type === 'model_output');
console.log(modelStep.content[0].text);

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "input": "Tell me a joke."
}'

# Response
{
  "id": "int_123",
  "status": "completed",
  "steps": [
    {
      "type": "user_input",
      "status": "done",
      "content": [
        {
          "type": "text",
          "text": "Tell me a joke."
        }
      ]
    },
    {
      "type": "model_output",
      "status": "done",
      "content": [
        {
          "type": "text",
          "text": "Why did the chicken cross the road?"
        }
      ]
    }
  ]
}

マルチターンの会話

Interactions API はデフォルトでインタラクションを保存し、マルチターンの会話のサーバーサイドの状態管理を有効にします。

移行前（generateContent）

generateContent では、contents 配列またはクライアントサイドのチャット ヘルパーを使用して、会話履歴を手動で管理する必要があります。

Python

チャット ヘルパーを使用する（推奨）

from google import genai

client = genai.Client()

chat = client.chats.create(model="gemini-2.5-flash")
response1 = chat.send_message("Hi, my name is Phil.")
print(response1.text)

response2 = chat.send_message("What is my name?")
print(response2.text)

履歴を手動で管理する

from google import genai
from google.genai import types

client = genai.Client()

# The second turn requires sending the entire history
response = client.models.generate_content(
    model="gemini-2.5-flash",
    contents=[
        types.Content(
            role="user", parts=[types.Part.from_text("Hi, my name is Phil.")]
        ),
        types.Content(
            role="model",
            parts=[types.Part.from_text("Hi Phil, how can I help you?")],
        ),
        types.Content(
            role="user", parts=[types.Part.from_text("What is my name?")]
        ),
    ],
)
print(response.text)

JavaScript

チャット ヘルパーを使用する（推奨）

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const chat = client.chats.create({ model: 'gemini-2.5-flash' });
let response = await chat.sendMessage({ message: 'Hi, my name is Phil.' });
console.log(response.text);

response = await chat.sendMessage({ message: 'What is my name?' });
console.log(response.text);

履歴を手動で管理する

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

// The second turn requires sending the entire history
const response = await client.models.generateContent({
    model: 'gemini-2.5-flash',
    contents: [
        { role: 'user', parts: [{ text: 'Hi, my name is Phil.' }] },
        { role: 'model', parts: [{ text: 'Hi Phil, how can I help you?' }] },
        { role: 'user', parts: [{ text: 'What is my name?' }] }
    ]
});
console.log(response.text);

REST

# Request (the second turn requires sending the entire history)
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [
        {"role": "user", "parts": [{"text": "Hi, my name is Phil."}]},
        {"role": "model", "parts": [{"text": "Hi Phil, how can I help you?"}]},
        {"role": "user", "parts": [{"text": "What is my name?"}]}
    ]
}'

# Response
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "text": "Your name is Phil."
          }
        ],
        "role": "model"
      },
      "finishReason": "STOP",
      "index": 0
    }
  ]
}

移行後（Interactions API）

Interactions API はサーバーで状態を管理します。previous_interaction_id を参照して会話を続けます。

Python

from google import genai

client = genai.Client()

# First turn
interaction1 = client.interactions.create(
    model="gemini-3-flash-preview", input="Hi, my name is Phil."
)
print(interaction1.steps[-1].content[0].text)

# Second turn (passing previous_interaction_id)
interaction2 = client.interactions.create(
    model="gemini-3-flash-preview",
    previous_interaction_id=interaction1.id,
    input="What is my name?",
)
print(interaction2.steps[-1].content[0].text)

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

// First turn
let interaction = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: 'Hi, my name is Phil.'
});
console.log(interaction.steps.at(-1).content[0].text);

// Second turn
interaction = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    previous_interaction_id: interaction.id,
    input: 'What is my name?'
});
console.log(interaction.steps.at(-1).content[0].text);

REST

# First Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "input": "Hi, my name is Phil."
}'

# Second Request (using ID from first response)
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "previous_interaction_id": "int_123",
    "input": "What is my name?"
}'

# Response to Second Request
{
  "id": "int_123",
  "steps": [
    {
      "type": "user_input",
      "status": "done",
      "content": [{ "type": "text", "text": "Hi, my name is Phil." }]
    },
    {
      "type": "model_output",
      "status": "done",
      "content": [{ "type": "text", "text": "Hello Phil! How can I help you today?" }]
    },
    {
      "type": "user_input",
      "status": "done",
      "content": [{ "type": "text", "text": "What is my name?" }]
    },
    {
      "type": "model_output",
      "status": "done",
      "content": [{ "type": "text", "text": "Your name is Phil." }]
    }
  ]
}

マルチモーダル入力

どちらの API もマルチモーダル入力（テキスト、画像、動画など）をサポートしています。

移行前（generateContent）

generateContent では、contents 配列内の parts のリストを渡します。レスポンスは、最初の候補の parts に出力を返します。

Python

from google import genai
from google.genai import types

client = genai.Client()

with open("sample.jpg", "rb") as f:
    image_bytes = f.read()

response = client.models.generate_content(
    model="gemini-2.5-flash",
    contents=[
        types.Part.from_bytes(data=image_bytes, mime_type="image/jpeg"),
        "Describe this image.",
    ],
)
print(response.text)

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [{
        "parts": [
            {
                "inlineData": {
                    "mimeType": "image/jpeg",
                    "data": "..."
                }
            },
            {
                "text": "Describe this image."
            }
        ]
    }]
}'

# Response
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "text": "This is a picture of a beautiful sunset."
          }
        ],
        "role": "model"
      }
    }
  ]
}

移行後（Interactions API）

Interactions API では、配列を input フィールドに渡します。タイムラインで model_output ステップを見つけて、出力コンテンツを取得します。

Python

from google import genai

client = genai.Client()

# Assuming you have an image file
with open("sample.jpg", "rb") as f:
    image_bytes = f.read()

interaction = client.interactions.create(
    model="gemini-3-flash-preview",
    input=[
        {
            "type": "image",
            "mime_type": "image/jpeg",
            "data": image_bytes,
        },
        {"type": "text", "text": "Describe this image."},
    ],
)
for step in interaction.steps:
    if step.type == "model_output":
        print(step.content[0].text)

JavaScript

import { GoogleGenAI } from '@google/genai';
import * as fs from 'fs';

const client = new GoogleGenAI({});

const imageBytes = fs.readFileSync('sample.jpg').toString('base64');

const interaction = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: [
        {
            type: 'image',
            mime_type: 'image/jpeg',
            data: imageBytes
        },
        {
            type: 'text',
            text: 'Describe this image.'
        }
    ]
});
for (const step of interaction.steps) {
    if (step.type === 'model_output') {
        console.log(step.content[0].text);
    }
}

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "input": [
        {
            "type": "image",
            "mime_type": "image/jpeg",
            "data": "..."
        },
        {
            "type": "text",
            "text": "Describe this image."
        }
    ]
}'

# Response
{
  "id": "int_multimodal",
  "steps": [
    {
      "type": "user_input",
      "status": "done",
      "content": [
        {
          "type": "image",
          "mime_type": "image/jpeg",
          "data": "..."
        },
        {
          "type": "text",
          "text": "Describe this image."
        }
      ]
    },
    {
      "type": "model_output",
      "status": "done",
      "content": [
        {
          "type": "text",
          "text": "This is a picture of a beautiful sunset over the mountains."
        }
      ]
    }
  ]
}

構造化出力

特定のスキーマに一致する JSON をモデルに返させるには、レスポンス形式を構成します。

移行前（generateContent）

generateContent では、generationConfig オブジェクト内にネストされた response_format フィールドを使用して出力形式を構成します。

Python

from google import genai
from google.genai import types
from pydantic import BaseModel

client = genai.Client()

class Recipe(BaseModel):
    recipe_name: str
    ingredients: list[str]

response = client.models.generate_content(
    model="gemini-2.5-flash",
    contents="Give me a recipe for chocolate chip cookies.",
    config=types.GenerateContentConfig(
        response_format=[
            {
                "type": "text",
                "mime_type": "application/json",
                "schema": Recipe,
            }
        ]
    ),
)
print(response.text)

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [{
        "parts": [{
            "text": "Give me a recipe for chocolate chip cookies."
        }]
    }],
    "generationConfig": {
        "responseFormat": [
            {
                "type": "text",
                "mimeType": "application/json",
                "schema": {
                    "type": "OBJECT",
                    "properties": {
                        "recipe_name": { "type": "STRING" },
                        "ingredients": {
                            "type": "ARRAY",
                            "items": { "type": "STRING" }
                        }
                    },
                    "required": ["recipe_name", "ingredients"]
                }
            }
        ]
    }
}'

# Response
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "text": "{\n  \"recipe_name\": \"Chocolate Chip Cookies\",\n  \"ingredients\": [\n    \"1 cup butter\",\n    \"1 cup sugar\",\n    \"2 cups flour\",\n    \"1 cup chocolate chips\"\n  ]\n}"
          }
        ],
        "role": "model"
      }
    }
  ]
}

移行後（Interactions API）

Interactions API では、出力形式の制御が最上位の response_format 配列に移動します。

Python

from google import genai
from pydantic import BaseModel

client = genai.Client()

class Recipe(BaseModel):
    recipe_name: str
    ingredients: list[str]

interaction = client.interactions.create(
    model="gemini-3-flash-preview",
    input="Give me a recipe for chocolate chip cookies.",
    response_format=[
        {
            "type": "text",
            "mime_type": "application/json",
            "schema": Recipe,
        }
    ],
)

for step in interaction.steps:
    if step.type == "model_output":
        print(step.content[0].text)

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const interaction = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: 'Give me a recipe for chocolate chip cookies.',
    response_format: [
        {
            type: 'text',
            mime_type: 'application/json',
            schema: {
                type: 'object',
                properties: {
                    recipe_name: { type: 'string' },
                    ingredients: {
                        type: 'array',
                        items: { type: 'string' }
                    }
                },
                required: ['recipe_name', 'ingredients']
            }
        }
    ]
});
for (const step of interaction.steps) {
    if (step.type === 'model_output') {
        console.log(step.content[0].text);
    }
}

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "input": "Give me a recipe for chocolate chip cookies.",
    "response_format": [
        {
            "type": "text",
            "mime_type": "application/json",
            "schema": {
                "type": "OBJECT",
                "properties": {
                    "recipe_name": { "type": "STRING" },
                    "ingredients": {
                        "type": "ARRAY",
                        "items": { "type": "STRING" }
                    }
                },
                "required": ["recipe_name", "ingredients"]
            }
        }
    ]
}'

# Response
{
  "id": "int_structured",
  "steps": [
    {
      "type": "user_input",
      "status": "done",
      "content": [{ "type": "text", "text": "Give me a recipe for chocolate chip cookies." }]
    },
    {
      "type": "model_output",
      "status": "done",
      "content": [
        {
          "type": "text",
          "text": "{\n  \"recipe_name\": \"Chocolate Chip Cookies\",\n  \"ingredients\": [\n    \"1 cup butter\",\n    \"1 cup sugar\",\n    \"2 cups flour\",\n    \"1 cup chocolate chips\"\n  ]\n}"
        }
      ]
    }
  ]
}

マルチモーダル生成

テキスト以外のモダリティ（画像や音声など）でコンテンツを生成する場合、主な違いは、生成されたメディアをレスポンスがどのように構造化するかです。

移行前（generateContent）

generateContent では、レスポンスは生成されたメディアを候補の parts に直接返します。通常は inlineData の base64 データとして返されます。

# Response structure concept
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "text": "Here is your generated image:"
          },
          {
            "inlineData": {
              "mimeType": "image/jpeg",
              "data": "...base64..."
            }
          }
        ]
      }
    }
  ]
}

移行後（Interactions API）

Interactions API では、生成されたメディアはタイムラインの model_output ステップの content 配列内の個別のアイテムとして表示され、インタラクションの時系列フローが維持されます。

# Response structure concept
{
  "id": "int_123",
  "steps": [
    {
      "type": "model_output",
      "status": "done",
      "content": [
        {
          "type": "text",
          "text": "Here is your generated image:"
        },
        {
          "type": "image",
          "mime_type": "image/jpeg",
          "data": "...base64..." // Or a reference URL in future
        }
      ]
    }
  ]
}

これにより、レスポンスの解析は入力とテキスト出力の処理方法と一貫性が保たれます。すべてがタイムラインのステップです。

サーバーサイド ツール

Gemini は、Google 検索のグラウンディングなどの組み込みのサーバーサイド ツールをサポートしています。主な違いは、レスポンスがツールの実行をどのように表すかです。

移行前（generateContent）

generateContent では、サーバーサイド ツールはほとんど不透明です。ツールを有効にして、別の groundingMetadata オブジェクトで最終的な回答を取得します。重要な点として、引用はインラインではありません。groundingSupports は文字インデックスを使用して、groundingChunks のテキスト セグメントをウェブソースにマッピングします。

Python

from google import genai
from google.genai import types

client = genai.Client()

response = client.models.generate_content(
    model="gemini-2.5-flash",
    contents="Who won Euro 2024?",
    config=types.GenerateContentConfig(
        tools=[{"google_search": {}}]
    ),
)

# Access search entry point (widget) and citations
metadata = response.candidates[0].grounding_metadata
if metadata.search_entry_point:
    print(f"Search Entry Point: {metadata.search_entry_point.rendered_content}")

for support in metadata.grounding_supports:
    print(f"Citation: {support.segment.text}")

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const response = await client.models.generateContent({
    model: 'gemini-2.5-flash',
    contents: 'Who won Euro 2024?',
    config: {
        tools: [{ google_search: {} }]
    }
});

const metadata = response.candidates[0].groundingMetadata;
if (metadata.searchEntryPoint) {
    console.log(`Search Entry Point: ${metadata.searchEntryPoint.renderedContent}`);
}
for (const support of metadata.groundingSupports) {
    console.log(`Citation: ${support.segment.text}`);
}

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [{
        "parts": [{
            "text": "Who won Euro 2024?"
        }]
    }],
    "tools": [{
        "googleSearchRetrieval": {}
    }]
}'

# Response
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "text": "Spain won Euro 2024, defeating England 2-1 in the final. This victory marks Spain's record fourth European Championship title."
          }
        ],
        "role": "model"
      },
      "groundingMetadata": {
        "webSearchQueries": [
          "UEFA Euro 2024 winner",
          "who won euro 2024"
        ],
        "searchEntryPoint": {
          "renderedContent": "<!-- HTML and CSS for the search widget -->"
        },
        "groundingChunks": [
          {"web": {"uri": "https://vertexaisearch.cloud.google.com.....", "title": "aljazeera.com"}},
          {"web": {"uri": "https://vertexaisearch.cloud.google.com.....", "title": "uefa.com"}}
        ],
        "groundingSupports": [
          {
            "segment": {"startIndex": 0, "endIndex": 85, "text": "Spain won Euro 2024, defeatin..."},
            "groundingChunkIndices": [0]
          },
          {
            "segment": {"startIndex": 86, "endIndex": 210, "text": "This victory marks Spain's..."},
            "groundingChunkIndices": [0, 1]
          }
        ]
      }
    }
  ]
}

移行後（Interactions API）

Interactions API では、サーバーサイド ツールはタイムラインの完全な透明性を提供します。API は呼び出しと結果を個別の実行 steps（google_search_call と google_search_result）として記録し、モデルが取得したデータを正確に公開します。

さらに、API は引用をインライン で返します。別のメタデータ オブジェクトからインデックスをマッピングする代わりに、model_output ステップ内のテキスト アイテムには、ソースに直接リンクする独自の annotations 配列が含まれています。

Python

from google import genai

client = genai.Client()

interaction = client.interactions.create(
    model="gemini-3-flash-preview",
    input="Who won Euro 2024?",
    tools=[{"type": "google_search"}],
)

for step in interaction.steps:
    if step.type == "google_search_result":
        print(f"Search Suggestions: {step.search_suggestions}")
    elif step.type == "model_output":
        print(f"Answer: {step.content[0].text}")
        if step.content[0].annotations:
            for anno in step.content[0].annotations:
                print(f"Citation: {anno.title} ({anno.uri})")

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const interaction = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: 'Who won Euro 2024?',
    tools: [{ type: 'google_search' }]
});

for (const step of interaction.steps) {
    if (step.type === 'google_search_result') {
        console.log(`Search Suggestions: ${step.search_suggestions}`);
    } else if (step.type === 'model_output') {
        console.log(`Answer: ${step.content[0].text}`);
        if (step.content[0].annotations) {
            for (const anno of step.content[0].annotations) {
                console.log(`Citation: ${anno.title} (${anno.uri})`);
            }
        }
    }
}

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "input": "Who won Euro 2024?",
    "tools": [{"type": "google_search"}]
}'

# Response (showing grounding)
{
  "id": "int_grounded",
  "steps": [
    {
      "type": "user_input",
      "status": "done",
      "content": [{ "type": "text", "text": "Who won Euro 2024?" }]
    },
    {
      "type": "google_search_call",
      "status": "done",
      "content": [{ "type": "text", "text": "UEFA Euro 2024 winner" }]
    },
    {
      "type": "google_search_result",
      "status": "done",
      "content": [
        {
          "type": "text",
          "text": "Spain won Euro 2024..." 
        }
      ]
    },
    {
      "type": "model_output",
      "status": "done",
      "content": [
        {
          "type": "text",
          "text": "Spain won Euro 2024, defeating England 2-1.",
          "annotations": [
            {
              "start_index": 0,
              "end_index": 42,
              "uri": "https://vertexaisearch...",
              "title": "aljazeera.com"
            }
          ]
        }
      ]
    }
  ]
}

関数呼び出し

関数呼び出しと結果の構造も、ステップ スキーマに合わせて変更されています。

移行前（generateContent）

generateContent では、レスポンスは候補内の関数呼び出しを返します。

Python

from google import genai
from google.genai import types

client = genai.Client()

# Step 1: Send prompt with tools
response = client.models.generate_content(
    model="gemini-2.5-flash",
    contents="What's the weather in Boston?",
    config=types.GenerateContentConfig(tools=[weather_tool]),
)

# Assume model returned function_call
function_call = response.candidates[0].content.parts[0].function_call
print(f"Requested tool: {function_call.name}")

# Step 2: Execute local function and send result back
result = "52°F and rain"

response = client.models.generate_content(
    model="gemini-2.5-flash",
    contents=[
        types.Content(
            role="user",
            parts=[
                types.Part.from_text(text="What's the weather in Boston?")
            ],
        ),
        response.candidates[0].content,  # Model turn with function call
        types.Content(
            role="user",
            parts=[
                types.Part.from_function_response(
                    name=function_call.name,
                    response={"result": result},
                )
            ],
        ),
    ],
    config=types.GenerateContentConfig(tools=[weather_tool]),
)
print(response.text)

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

// Step 1: Send prompt with tools
let response = await client.models.generateContent({
    model: 'gemini-2.5-flash',
    contents: "What's the weather in Boston?",
    config: { tools: [weatherTool] }
});

const functionCall = response.candidates[0].content.parts[0].functionCall;
console.log(`Requested tool: ${functionCall.name}`);

// Step 2: Execute local function and send result back
const result = "52°F and rain";

response = await client.models.generateContent({
    model: 'gemini-2.5-flash',
    contents: [
        { role: 'user', parts: [{ text: "What's the weather in Boston?" }] },
        response.candidates[0].content, // Model turn
        {
            role: 'user',
            parts: [{
                functionResponse: {
                    name: functionCall.name,
                    response: { result: result }
                }
            }]
        }
    ],
    config: { tools: [weatherTool] }
});
console.log(response.text);

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [{
        "parts": [{
            "text": "What is the weather like in Boston, MA?"
        }]
    }],
    "tools": [{
        "functionDeclarations": [{
            "name": "get_weather",
            "description": "Get the current weather",
            "parameters": {
                "type": "OBJECT",
                "properties": {
                    "location": {"type": "STRING"}
                },
                "required": ["location"]
            }
        }]
    }]
}'

# Response
{
  "candidates": [
    {
      "content": {
        "parts": [
          {
            "functionCall": {
              "name": "get_weather",
              "args": { "location": "Boston, MA" }
            }
          }
        ],
        "role": "model"
      },
      "finishReason": "STOP",
      "index": 0
    }
  ]
}

移行後（Interactions API）

ツール呼び出しと結果は、タイムラインの個別のステップになりました。

Python

from google import genai

client = genai.Client()

weather_tool = {
    "type": "function",
    "name": "get_weather",
    "description": "Gets weather",
    "parameters": {
        "type": "object",
        "properties": {
            "location": {"type": "string"}
        },
    },
}

interaction = client.interactions.create(
    model="gemini-3-flash-preview",
    input="What's the weather in Boston?",
    tools=[weather_tool],
)

# Check if the model requested a tool call
for step in interaction.steps:
    if step.type == "function_call":
        print(f"Executing {step.name} for {step.arguments}")

        # Execute your local function here...
        result = "52°F and rain"

        # Submit the result back as a step
        interaction = client.interactions.create(
            model="gemini-3-flash-preview",
            previous_interaction_id=interaction.id,
            input=[
                {
                    "type": "function_result",
                    "call_id": step.id,
                    "name": step.name,
                    "result": [{"type": "text", "text": result}],
                }
            ],
        )
        # Inspect steps for final response
        for s in interaction.steps:
            if s.type == "model_output":
                print(s.content[0].text)

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const weatherTool = {
    type: "function",
    name: "get_weather",
    description: "Get weather for a location",
    parameters: {
        type: "object",
        properties: {
            location: { type: "string" }
        },
        required: ["location"]
    }
};

const interaction = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: "What's the weather in Boston?",
    tools: [weatherTool]
});

// Check if the model requested a tool call
for (const step of interaction.steps) {
    if (step.type === 'function_call') {
        console.log(`Executing ${step.name} for ${JSON.stringify(step.arguments)}`);

        const result = "52°F and rain";

        // Submit the result back as a step
        const nextInteraction = await client.interactions.create({
            model: 'gemini-3-flash-preview',
            previous_interaction_id: interaction.id,
            input: [
                {
                    type: 'function_result',
                    call_id: step.id,
                    name: step.name,
                    result: [{ type: 'text', text: result }]
                }
            ]
        });

        // Inspect steps for final response
        for (const s of nextInteraction.steps) {
            if (s.type === 'model_output') {
                console.log(s.content[0].text);
            }
        }
    }
}

REST

# Initial Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "input": "What's the weather in Boston?",
    "tools": [{
        "type": "function",
        "name": "get_weather",
        "description": "Get weather for a location",
        "parameters": {
            "type": "object",
            "properties": {
                "location": { "type": "string" }
            },
            "required": ["location"]
        }
    }]
}'

# Response (requires action)
{
  "id": "int_001",
  "status": "requires_action",
  "steps": [
    {
      "type": "user_input",
      "status": "done",
      "content": [
        { "type": "text", "text": "What's the weather in Boston?" }
      ]
    },
    {
      "type": "function_call",
      "status": "waiting",
      "id": "fc_1",
      "name": "get_weather",
      "arguments": { "location": "Boston, MA" }
    }
  ]
}

# Submit Tool Result Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "previous_interaction_id": "int_001",
    "input": {
        "type": "function_result",
        "call_id": "fc_1",
        "name": "get_weather",
        "result": [
            { "type": "text", "text": "52°F with rain" }
        ]
    }
}'

# Final Response
{
  "id": "int_002",
  "status": "completed",
  "steps": [
    {
      "type": "function_result",
      "call_id": "fc_1",
      "name": "get_weather",
      "result": [
        { "type": "text", "text": "52°F with rain" }
      ]
    },
    {
      "type": "model_output",
      "status": "done",
      "content": [
        { "type": "text", "text": "It's 52°F with rain in Boston." }
      ]
    }
  ]
}

ストリーミング

ストリーミングの主な違いは、Interactions API がリクエスト本文で "stream": true を使用して同じエンドポイントを使用するのに対し、generateContent API では専用のエンドポイント（:streamGenerateContent）を呼び出す必要があったことです。

また、ストリーミング イベントでは、特殊なタイプを使用してインタラクションのライフサイクルをモニタリングし、タイムラインに沿って実行ステップを追跡します。

移行前（generateContentStream）

generateContent を使用すると、レスポンス チャンクのストリームを使用します。

Python

response = client.models.generate_content_stream(
    model="gemini-2.5-flash", contents="Tell me a story"
)
for chunk in response:
    print(chunk.text, end="")

JavaScript

const responseStream = await client.models.generateContentStream({
    model: 'gemini-2.5-flash',
    contents: 'Tell me a story',
});
for await (const chunk of responseStream) {
    process.stdout.write(chunk.text);
}

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:streamGenerateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [{
        "parts": [{
            "text": "Tell me a story"
        }]
    }]
}'

# Response stream
event: content.start
data: {"event_type": "content.start", "index": 0, "content": {"type": "thought"}}
event: content.delta
data: {"event_type": "content.delta", "index": 0, "delta": {"type": "thought_summary", "text": "User wants an explanation."}}
event: content.stop
data: {"event_type": "content.stop", "index": 0}
event: content.start
data: {"event_type": "content.start", "index": 1, "content": {"type": "text"}}
event: content.delta
data: {"event_type": "content.delta", "index": 1, "delta": {"type": "text", "text": "Hello"}}
event: content.stop
data: {"event_type": "content.stop", "index": 1}

移行後（Interactions API）

Interactions API では、ストリーミングは Server-Sent Events（SSE）と特殊なデルタタイプを使用して、実行ステップを発生時に表現します。

Python

from google import genai

client = genai.Client()

stream = client.interactions.create(
    model="gemini-3-flash-preview",
    input="Tell me a story",
    stream=True,
)

for event in stream:
    if event.event_type == "step.delta":
        if event.delta.type == "text":
            print(event.delta.text, end="", flush=True)
    elif event.event_type == "interaction.complete":
        print(f"\n\n--- Stream Finished ---")

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const stream = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: 'Tell me a story',
    stream: true,
});

for await (const event of stream) {
    if (event.event_type === 'step.delta') {
        if (event.delta.type === 'text' && 'text' in event.delta) {
            process.stdout.write(event.delta.text);
        }
    } else if (event.event_type === 'interaction.complete') {
        console.log('\n\n--- Stream Finished ---');
    }
}

REST

# Example SSE stream output event: interaction.created data: {"type": "interaction.created", "interaction": {"id": "int_xyz", "status": "created"}} event: interaction.status_update data: {"type": "interaction.status_update", "status": "in_progress"}} event: step.start data: {"type": "step.start", "index": 0, "step": {"type": "thought"}} event: step.delta data: {"type": "step.delta", "index": 0, "delta": {"type": "thought", "text": "User wants an explanation."}} event: step.stop data: {"type": "step.stop", "index": 0, "status": "done"}} event: step.start data: {"type": "step.start", "index": 1, "step": {"type": "model_output"}} event: step.delta data: {"type": "step.delta", "index": 1, "delta": {"type": "text", "text": "Hello"}} event: step.stop data: {"type": "step.stop", "index": 1, "status": "done"}} event: interaction.complete data: {"type": "interaction.complete", "interaction": {"id": "int_xyz", "status": "completed", "usage": {"prompt_tokens": 10, "completion_tokens": 5, "total_tokens": 15}}} ```

ストリーミング ツールと関数呼び出し

ストリーム内のツールの動作は、generateContent から大幅に変更され、よりきめ細かい制御と可視性が提供されるようになりました。

移行前（generateContent）

generateContent では、ストリーミング関数呼び出しは 1 つのチャンクで完了しました。引数がリアルタイムで生成されるのを確認できなかったため、ハンドラは完全な functionCall オブジェクトを確認するだけでした。

Python

from google import genai
from google.genai import types

client = genai.Client()

stream = client.models.generate_content_stream(
    model="gemini-2.5-flash",
    contents="What's the weather in Boston?",
    config=types.GenerateContentConfig(tools=[weather_tool]),
)

for chunk in stream:
    # Function calls arrived complete — no partial arguments
    if chunk.candidates[0].content.parts[0].function_call:
        fc = chunk.candidates[0].content.parts[0].function_call
        print(f"Call: {fc.name}({fc.args})")
    elif chunk.text:
        print(chunk.text, end="")

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const stream = await client.models.generateContentStream({
    model: 'gemini-2.5-flash',
    contents: "What's the weather in Boston?",
    config: { tools: [weatherTool] }
});

for await (const chunk of stream) {
    // Function calls arrived complete — no partial arguments
    const part = chunk.candidates[0].content.parts[0];
    if (part.functionCall) {
        console.log(`Call: ${part.functionCall.name}(${JSON.stringify(part.functionCall.args)})`);
    } else if (part.text) {
        process.stdout.write(part.text);
    }
}

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:streamGenerateContent" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "contents": [{"parts": [{"text": "What'\''s the weather in Boston?"}]}],
    "tools": [{"functionDeclarations": [{"name": "get_weather", "parameters": {"type": "OBJECT", "properties": {"location": {"type": "STRING"}}}}]}]
}'

# Response stream — function call arrives complete in one chunk
{"candidates": [{"content": {"parts": [{"functionCall": {"name": "get_weather", "args": {"location": "Boston, MA"}}}]}}]}

移行後（Interactions API）

Interactions API は、関数呼び出し引数を arguments イベントとして文字単位でストリーミングします。思考、呼び出し、結果、出力など、ツール ライフサイクル全体が、一連の個別のステップとして実行されます。

Python

from google import genai

client = genai.Client()

stream = client.interactions.create(
    model="gemini-3-flash-preview",
    input="What's the weather in Boston?",
    tools=[get_weather_tool],
    stream=True,
)

for event in stream:
    if event.event_type == "step.start":
        if event.step.type == "function_call":
            print(f"Calling: {event.step.name}")
    elif event.event_type == "step.delta":
        if event.delta.type == "arguments":
            print(f"  args: {event.delta.partial_arguments}")
        elif event.delta.type == "text":
            print(event.delta.text, end="")
    elif event.event_type == "interaction.complete":
        print("\n--- Done ---")

JavaScript

import { GoogleGenAI } from '@google/genai';

const client = new GoogleGenAI({});

const stream = await client.interactions.create({
    model: 'gemini-3-flash-preview',
    input: "What's the weather in Boston?",
    tools: [getWeatherTool],
    stream: true,
});

for await (const event of stream) {
    if (event.event_type === 'step.start') {
        if (event.step.type === 'function_call') {
            console.log(`Calling: ${event.step.name}`);
        }
    } else if (event.event_type === 'step.delta') {
        if (event.delta.type === 'arguments') {
            console.log(`  args: ${event.delta.partial_arguments}`);
        } else if (event.delta.type === 'text') {
            process.stdout.write(event.delta.text);
        }
    } else if (event.event_type === 'interaction.complete') {
        console.log('\n--- Done ---');
    }
}

REST

# Request
curl -X POST "https://generativelanguage.googleapis.com/v1beta2/interactions" \
-H "Content-Type: application/json" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-d '{
    "model": "gemini-3-flash-preview",
    "input": "What'\''s the weather in Boston?",
    "tools": [{"type": "function", "name": "get_weather", "parameters": {"type": "object", "properties": {"location": {"type": "string"}}}}],
    "stream": true
}'

# Response stream
// Interaction created
event: interaction.created
data: {"type": "interaction.created", "interaction": {"id": "int_xyz", "status": "created"}}

event: interaction.status_update
data: {"type": "interaction.status_update", "status": "in_progress"}

// ── Step 0: Thought ──────────────────────────────────
event: step.start
data: {"type": "step.start", "index": 0, "step": {"type": "thought"}}

event: step.delta
data: {"type": "step.delta", "index": 0, "delta": {"type": "thought", "text": "The user wants weather data for Boston. I'll call the get_weather tool."}}

event: step.stop
data: {"type": "step.stop", "index": 0, "status": "done"}

// ── Step 1: Function Call (arguments streamed) ───────
event: step.start
data: {"type": "step.start", "index": 1, "step": {"type": "function_call", "id": "fc_1", "name": "get_weather"}}

event: step.delta
data: {"type": "step.delta", "index": 1, "delta": {"type": "arguments", "partial_arguments": "{\"location\": \"Boston, MA\"}"}}

event: step.stop
data: {"type": "step.stop", "index": 1, "status": "waiting"}

// The interaction pauses — the model needs the tool result before continuing.
event: interaction.status_update
data: {"type": "interaction.status_update", "status": "requires_action"}

// ── (Client submits the tool result) ──────────────────
// The client calls interactions.create with the function_result as input
// and the previous interaction's ID, then resumes consuming the stream.

event: interaction.status_update
data: {"type": "interaction.status_update", "status": "in_progress"}

// ── Step 2: Function Result (echoed back, no deltas) ─
event: step.start
data: {"type": "step.start", "index": 2, "step": {"type": "function_result", "call_id": "fc_1", "name": "get_weather", "result": [{"type": "text", "text": "52°F, rain"}]}}

event: step.stop
data: {"type": "step.stop", "index": 2, "status": "done"}

// ── Step 3: Thought ──────────────────────────────────
event: step.start
data: {"type": "step.start", "index": 3, "step": {"type": "thought"}}

event: step.delta
data: {"type": "step.delta", "index": 3, "delta": {"type": "thought", "text": "Got weather data. Composing the final response."}}

event: step.stop
data: {"type": "step.stop", "index": 3, "status": "done"}

// ── Step 4: Model Output (text streamed) ─────────────
event: step.start
data: {"type": "step.start", "index": 4, "step": {"type": "model_output"}}

event: step.delta
data: {"type": "step.delta", "index": 4, "delta": {"type": "text", "text": "It's currently 52°F and rainy in Boston."}}

event: step.stop
data: {"type": "step.stop", "index": 4, "status": "done"}

// ── Interaction complete ─────────────────────────────
event: interaction.complete
data: {"type": "interaction.complete", "interaction": {"id": "int_xyz", "status": "completed", "usage": {"prompt_tokens": 256, "completion_tokens": 128, "total_tokens": 384}}}

ストリーム内のサーバーサイド ツール

Google 検索などのサーバーサイド ツールは、ストリーム内の関数呼び出しとは動作が異なります。呼び出しと結果は、デルタなしで step.start イベントで完了 します。step.start の直後に step.stop が続きます。

// Server-side tool call — payload arrives complete in step.start
event: step.start
data: {"type": "step.start", "index": 4, "step": {"type": "google_search_call", "id": "gs_2", "query": "Alphabet Q4 2025 earnings"}}

event: step.stop
data: {"type": "step.stop", "index": 4, "status": "done"}

// Server-side tool result — also complete in step.start
event: step.start
data: {"type": "step.start", "index": 5, "step": {"type": "google_search_result", "call_id": "gs_2", "rendered_content": "<div>Alphabet Q4 2025 Revenue: $105.6B</div>", "signature": "abc123..."}}

event: step.stop
data: {"type": "step.stop", "index": 5, "status": "done"}