Puoi configurare i modelli Gemini per generare risposte che rispettino uno schema JSON fornito. Ciò garantisce risultati prevedibili e sicuri per il tipo e semplifica l'estrazione di dati strutturati da testo non strutturato.
L'utilizzo di output strutturati è ideale per:
- Estrazione dei dati: estrai informazioni specifiche come nomi e date dal testo.
- Classificazione strutturata:classifica il testo in categorie predefinite.
- Workflow agentici:genera input strutturati per strumenti o API.
Oltre a supportare JSON Schema nell'API REST, gli SDK Google GenAI consentono di definire gli schemi utilizzando Pydantic (Python) e Zod (JavaScript).
Esempi di output strutturato
Estrattore di ricette
Questo esempio mostra come estrarre dati strutturati dal testo utilizzando tipi di schema JSON di base come object, array, string e integer.
Python
from google import genai
from pydantic import BaseModel, Field
from typing import List, Optional
class Ingredient(BaseModel):
name: str = Field(description="Name of the ingredient.")
quantity: str = Field(description="Quantity of the ingredient, including units.")
class Recipe(BaseModel):
recipe_name: str = Field(description="The name of the recipe.")
prep_time_minutes: Optional[int] = Field(description="Optional time in minutes to prepare the recipe.")
ingredients: List[Ingredient]
instructions: List[str]
client = genai.Client()
prompt = """
Please extract the recipe from the following text.
The user wants to make delicious chocolate chip cookies.
They need 2 and 1/4 cups of all-purpose flour, 1 teaspoon of baking soda,
1 teaspoon of salt, 1 cup of unsalted butter (softened), 3/4 cup of granulated sugar,
3/4 cup of packed brown sugar, 1 teaspoon of vanilla extract, and 2 large eggs.
For the best part, they'll need 2 cups of semisweet chocolate chips.
First, preheat the oven to 375°F (190°C). Then, in a small bowl, whisk together the flour,
baking soda, and salt. In a large bowl, cream together the butter, granulated sugar, and brown sugar
until light and fluffy. Beat in the vanilla and eggs, one at a time. Gradually beat in the dry
ingredients until just combined. Finally, stir in the chocolate chips. Drop by rounded tablespoons
onto ungreased baking sheets and bake for 9 to 11 minutes.
"""
interaction = client.interactions.create(
model="gemini-3.5-flash",
input=prompt,
response_format={
"type": "text",
"mime_type": "application/json",
"schema": Recipe.model_json_schema()
},
)
recipe = Recipe.model_validate_json(interaction.output_text)
print(recipe)
JavaScript
// Note: Ensure zod is installed (npm install zod)
import { GoogleGenAI } from "@google/genai";
import * as z from "zod";
const recipeJsonSchema = {
type: "object",
properties: {
recipe_name: {
type: "string",
description: "The name of the recipe."
},
prep_time_minutes: {
type: "integer",
description: "Optional time in minutes to prepare the recipe."
},
ingredients: {
type: "array",
items: {
type: "object",
properties: {
name: { type: "string", description: "Name of the ingredient."},
quantity: { type: "string", description: "Quantity of the ingredient, including units."}
},
required: ["name", "quantity"]
}
},
instructions: {
type: "array",
items: { type: "string" }
}
},
required: ["recipe_name", "ingredients", "instructions"]
};
const recipeSchema = z.fromJSONSchema(recipeJsonSchema);
const client = new GoogleGenAI({});
const prompt = `
Please extract the recipe from the following text.
The user wants to make delicious chocolate chip cookies.
They need 2 and 1/4 cups of all-purpose flour, 1 teaspoon of baking soda,
1 teaspoon of salt, 1 cup of unsalted butter (softened), 3/4 cup of granulated sugar,
3/4 cup of packed brown sugar, 1 teaspoon of vanilla extract, and 2 large eggs.
For the best part, they'll need 2 cups of semisweet chocolate chips.
First, preheat the oven to 375°F (190°C). Then, in a small bowl, whisk together the flour,
baking soda, and salt. In a large bowl, cream together the butter, granulated sugar, and brown sugar
until light and fluffy. Beat in the vanilla and eggs, one at a time. Gradually beat in the dry
ingredients until just combined. Finally, stir in the chocolate chips. Drop by rounded tablespoons
onto ungreased baking sheets and bake for 9 to 11 minutes.
`;
const interaction = await client.interactions.create({
model: "gemini-3.5-flash",
input: prompt,
response_format: {
type: 'text',
mime_type: 'application/json',
schema: recipeJsonSchema
},
});
const recipe = recipeSchema.parse(JSON.parse(interaction.output_text));
console.log(recipe);
REST
curl -X POST "https://generativelanguage.googleapis.com/v1beta/interactions" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "gemini-3.5-flash",
"input": "Please extract the recipe from the following text.\nThe user wants to make delicious chocolate chip cookies.\nThey need 2 and 1/4 cups of all-purpose flour, 1 teaspoon of baking soda,\n1 teaspoon of salt, 1 cup of unsalted butter (softened), 3/4 cup of granulated sugar,\n3/4 cup of packed brown sugar, 1 teaspoon of vanilla extract, and 2 large eggs.\nFor the best part, they will need 2 cups of semisweet chocolate chips.\nFirst, preheat the oven to 375°F (190°C). Then, in a small bowl, whisk together the flour,\nbaking soda, and salt. In a large bowl, cream together the butter, granulated sugar, and brown sugar\nuntil light and fluffy. Beat in the vanilla and eggs, one at a time. Gradually beat in the dry\ningredients until just combined. Finally, stir in the chocolate chips. Drop by rounded tablespoons\nonto ungreased baking sheets and bake for 9 to 11 minutes.",
"response_format": {
"type": "text",
"mime_type": "application/json",
"schema": {
"type": "object",
"properties": {
"recipe_name": {
"type": "string",
"description": "The name of the recipe."
},
"prep_time_minutes": {
"type": "integer",
"description": "Optional time in minutes to prepare the recipe."
},
"ingredients": {
"type": "array",
"items": {
"type": "object",
"properties": {
"name": { "type": "string", "description": "Name of the ingredient."},
"quantity": { "type": "string", "description": "Quantity of the ingredient, including units."}
},
"required": ["name", "quantity"]
}
},
"instructions": {
"type": "array",
"items": { "type": "string" }
}
},
"required": ["recipe_name", "ingredients", "instructions"]
}
}
}
}'
Esempio di risposta:
{
"recipe_name": "Delicious Chocolate Chip Cookies",
"ingredients": [
{ "name": "all-purpose flour", "quantity": "2 and 1/4 cups" },
{ "name": "baking soda", "quantity": "1 teaspoon" },
{ "name": "salt", "quantity": "1 teaspoon" },
{ "name": "unsalted butter (softened)", "quantity": "1 cup" },
{ "name": "granulated sugar", "quantity": "3/4 cup" },
{ "name": "packed brown sugar", "quantity": "3/4 cup" },
{ "name": "vanilla extract", "quantity": "1 teaspoon" },
{ "name": "large eggs", "quantity": "2" },
{ "name": "semisweet chocolate chips", "quantity": "2 cups" }
],
"instructions": [
"Preheat the oven to 375°F (190°C).",
"In a small bowl, whisk together the flour, baking soda, and salt.",
"In a large bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy.",
"Beat in the vanilla and eggs, one at a time.",
"Gradually beat in the dry ingredients until just combined.",
"Stir in the chocolate chips.",
"Drop by rounded tablespoons onto ungreased baking sheets and bake for 9 to 11 minutes."
]
}
Moderazione dei contenuti
Questo esempio mostra anyOf per gli schemi condizionali e enum per la
classificazione, consentendo alla struttura dell'output di variare in base ai contenuti.
Python
from google import genai
from pydantic import BaseModel, Field
from typing import Union, Literal
class SpamDetails(BaseModel):
reason: str = Field(description="The reason why the content is considered spam.")
spam_type: Literal["phishing", "scam", "unsolicited promotion", "other"] = Field(description="The type of spam.")
class NotSpamDetails(BaseModel):
summary: str = Field(description="A brief summary of the content.")
is_safe: bool = Field(description="Whether the content is safe for all audiences.")
class ModerationResult(BaseModel):
decision: Union[SpamDetails, NotSpamDetails]
client = genai.Client()
prompt = """
Please moderate the following content and provide a decision.
Content: 'Congratulations! You''ve won a free cruise to the Bahamas. Click here to claim your prize: www.definitely-not-a-scam.com'
"""
interaction = client.interactions.create(
model="gemini-3.5-flash",
input=prompt,
response_format={
"type": "text",
"mime_type": "application/json",
"schema": ModerationResult.model_json_schema()
},
)
result = ModerationResult.model_validate_json(interaction.output_text)
print(result)
JavaScript
// Note: Ensure zod is installed (npm install zod)
import { GoogleGenAI } from "@google/genai";
import * as z from "zod";
const moderationResultJsonSchema = {
type: "object",
properties: {
decision: {
anyOf: [
{
type: "object",
title: "SpamDetails",
description: "Details for content classified as spam.",
properties: {
reason: { type: "string", description: "The reason why the content is considered spam." },
spam_type: { type: "string", enum: ["phishing", "scam", "unsolicited promotion", "other"], description: "The type of spam." }
},
required: ["reason", "spam_type"]
},
{
type: "object",
title: "NotSpamDetails",
description: "Details for content classified as not spam.",
properties: {
summary: { type: "string", description: "A brief summary of the content." },
is_safe: { type: "boolean", description: "Whether the content is safe for all audiences." }
},
required: ["summary", "is_safe"]
}
]
}
},
required: ["decision"]
};
const moderationResultSchema = z.fromJSONSchema(moderationResultJsonSchema);
const client = new GoogleGenAI({});
const prompt = `
Please moderate the following content and provide a decision.
Content: 'Congratulations! You''ve won a free cruise to the Bahamas. Click here to claim your prize: www.definitely-not-a-scam.com'
`;
const interaction = await client.interactions.create({
model: "gemini-3.5-flash",
input: prompt,
response_format: {
type: 'text',
mime_type: 'application/json',
schema: moderationResultJsonSchema
},
});
const result = moderationResultSchema.parse(JSON.parse(interaction.output_text));
console.log(result);
REST
curl -X POST "https://generativelanguage.googleapis.com/v1beta/interactions" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "gemini-3.5-flash",
"input": "Please moderate the following content and provide a decision.\nContent: '\''Congratulations! You have won a free cruise to the Bahamas. Click here to claim your prize: www.definitely-not-a-scam.com'\''",
"response_format": {
"type": "text",
"mime_type": "application/json",
"schema": {
"type": "object",
"properties": {
"decision": {
"anyOf": [
{
"type": "object",
"title": "SpamDetails",
"description": "Details for content classified as spam.",
"properties": {
"reason": { "type": "string", "description": "The reason why the content is considered spam." },
"spam_type": { "type": "string", "enum": ["phishing", "scam", "unsolicited promotion", "other"], "description": "The type of spam." }
},
"required": ["reason", "spam_type"]
},
{
"type": "object",
"title": "NotSpamDetails",
"description": "Details for content classified as not spam.",
"properties": {
"summary": { "type": "string", "description": "A brief summary of the content." },
"is_safe": { "type": "boolean", "description": "Whether the content is safe for all audiences." }
},
"required": ["summary", "is_safe"]
}
]
}
},
"required": ["decision"]
}
}
}
}'
Esempio di risposta:
{
"decision": {
"reason": "The content is an unsolicited prize notification attempting to trick the user into clicking a suspicious link.",
"spam_type": "scam"
}
}
Strutture ricorsive
Questo esempio illustra come definire uno schema ricorsivo, ad esempio un organigramma.
Python
from google import genai
from pydantic import BaseModel, Field
from typing import List
class Employee(BaseModel):
"""Represents an employee in an organization."""
name: str
employee_id: int
reports: List["Employee"] = Field(
default_factory=list,
description="A list of employees reporting to this employee."
)
client = genai.Client()
prompt = """
Generate an organization chart for a small team.
The manager is Alice, who manages Bob and Charlie. Bob manages David.
"""
interaction = client.interactions.create(
model="gemini-3.5-flash",
input=prompt,
response_format={
"type": "text",
"mime_type": "application/json",
"schema": Employee.model_json_schema()
},
)
employee = Employee.model_validate_json(interaction.output_text)
print(employee)
JavaScript
// Note: Ensure zod is installed (npm install zod)
import { GoogleGenAI } from "@google/genai";
import * as z from "zod";
const employeeJsonSchema = {
type: "object",
properties: {
name: { type: "string" },
employee_id: { type: "integer" },
reports: {
type: "array",
description: "A list of employees reporting to this employee.",
items: {
"$ref": "#"
}
}
},
required: ["name", "employee_id", "reports"]
};
const employeeSchema = z.fromJSONSchema(employeeJsonSchema);
const client = new GoogleGenAI({});
const prompt = `
Generate an organization chart for a small team.
The manager is Alice, who manages Bob and Charlie. Bob manages David.
`;
const interaction = await client.interactions.create({
model: "gemini-3.5-flash",
input: prompt,
response_format: {
type: 'text',
mime_type: 'application/json',
schema: employeeJsonSchema
},
});
const employee = employeeSchema.parse(JSON.parse(interaction.output_text));
console.log(employee);
REST
curl -X POST "https://generativelanguage.googleapis.com/v1beta/interactions" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "gemini-3.5-flash",
"input": "Generate an organization chart for a small team.\nThe manager is Alice, who manages Bob and Charlie. Bob manages David.",
"response_format": {
"type": "text",
"mime_type": "application/json",
"schema": {
"type": "object",
"properties": {
"name": { "type": "string" },
"employee_id": { "type": "integer" },
"reports": {
"type": "array",
"description": "A list of employees reporting to this employee.",
"items": {
"$ref": "#"
}
}
},
"required": ["name", "employee_id", "reports"]
}
}
}
}'
Esempio di risposta:
{
"name": "Alice",
"employee_id": 101,
"reports": [
{
"name": "Bob",
"employee_id": 102,
"reports": [
{
"name": "David",
"employee_id": 104,
"reports": []
}
]
},
{
"name": "Charlie",
"employee_id": 103,
"reports": []
}
]
}
Risultati in streaming
Puoi trasmettere in streaming gli output strutturati, il che ti consente di iniziare a elaborare la risposta durante la generazione. I blocchi trasmessi in streaming sono stringhe JSON parziali valide che possono essere concatenate per formare l'oggetto JSON finale.
Python
from google import genai
from pydantic import BaseModel
from typing import Literal
class Feedback(BaseModel):
sentiment: Literal["positive", "neutral", "negative"]
summary: str
client = genai.Client()
prompt = "The new UI is incredibly intuitive. Add a very long summary to test streaming!"
stream = client.interactions.create(
model="gemini-3.5-flash",
input=prompt,
response_format={
"type": "text",
"mime_type": "application/json",
"schema": Feedback.model_json_schema()
},
stream=True
)
for event in stream:
if event.event_type == "step.delta":
if event.delta.type == "text" and getattr(event.delta, "text", None):
print(event.delta.text, end="", flush=True)
JavaScript
// Note: Ensure zod is installed (npm install zod)
import { GoogleGenAI } from "@google/genai";
import * as z from "zod";
const feedbackJsonSchema = {
type: "object",
properties: {
sentiment: { type: "string", enum: ["positive", "neutral", "negative"] },
summary: { type: "string" }
},
required: ["sentiment", "summary"]
};
const feedbackSchema = z.fromJSONSchema(feedbackJsonSchema);
const client = new GoogleGenAI({});
const stream = await client.interactions.create({
model: "gemini-3.5-flash",
input: "The new UI is incredibly intuitive. Add a very long summary!",
response_format: {
type: 'text',
mime_type: 'application/json',
schema: feedbackJsonSchema
},
stream: true,
});
for await (const event of stream) {
if (event.event_type === "step.delta") {
if (event.delta.type === "text") {
process.stdout.write(event.delta.text);
}
}
}
REST
curl -N -X POST "https://generativelanguage.googleapis.com/v1beta/interactions" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "gemini-3.5-flash",
"input": "The new UI is incredibly intuitive. Add a very long summary!",
"response_format": {
"type": "text",
"mime_type": "application/json",
"schema": {
"type": "object",
"properties": {
"sentiment": { "type": "string", "enum": ["positive", "neutral", "negative"] },
"summary": { "type": "string" }
},
"required": ["sentiment", "summary"]
}
},
"stream": true
}'
Output strutturati con strumenti
Gemini 3 ti consente di combinare gli output strutturati con strumenti integrati, tra cui Grounding con la Ricerca Google, Contesto URL, Esecuzione di codice, Ricerca file e Chiamata di funzioni.
Python
from google import genai
from pydantic import BaseModel, Field
from typing import List
class MatchResult(BaseModel):
winner: str = Field(description="The name of the winner.")
final_match_score: str = Field(description="The final match score.")
scorers: List[str] = Field(description="The name of the scorer.")
client = genai.Client()
interaction = client.interactions.create(
model="gemini-3.1-pro-preview",
input="Search for all details for the latest Euro.",
tools=[{"type": "google_search"}, {"type": "url_context"}],
response_format={
"type": "text",
"mime_type": "application/json",
"schema": MatchResult.model_json_schema()
},
)
result = MatchResult.model_validate_json(interaction.output_text)
print(result)
JavaScript
// Note: Ensure zod is installed (npm install zod)
import { GoogleGenAI } from "@google/genai";
import * as z from "zod";
const matchJsonSchema = {
type: "object",
properties: {
winner: { type: "string" },
final_match_score: { type: "string" },
scorers: { type: "array", items: { type: "string" } }
},
required: ["winner", "final_match_score", "scorers"]
};
const matchSchema = z.fromJSONSchema(matchJsonSchema);
const client = new GoogleGenAI({});
const interaction = await client.interactions.create({
model: "gemini-3.1-pro-preview",
input: "Search for all details for the latest Euro.",
tools: [{type: "google_search"}, {type: "url_context"}],
response_format: {
type: 'text',
mime_type: 'application/json',
schema: matchJsonSchema
},
});
const match = matchSchema.parse(JSON.parse(interaction.output_text));
console.log(match);
REST
curl -X POST "https://generativelanguage.googleapis.com/v1beta/interactions" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "gemini-3.1-pro-preview",
"input": "Search for all details for the latest Euro.",
"tools": [{"type": "google_search"}, {"type": "url_context"}],
"response_format": {
"type": "text",
"mime_type": "application/json",
"schema": {
"type": "object",
"properties": {
"winner": {"type": "string"},
"final_match_score": {"type": "string"},
"scorers": {"type": "array", "items": {"type": "string"}}
},
"required": ["winner", "final_match_score", "scorers"]
}
}
}'
Supporto dello schema JSON
Per generare un oggetto JSON, configura response_format con un oggetto (o un array contenente un oggetto) di tipo text e imposta mime_type su application/json. Lo schema deve essere fornito nel campo schema.
La modalità di output strutturato di Gemini supporta un sottoinsieme della specifica JSON Schema.
Sono supportati i seguenti valori di type:
string: per il testo.number: per i numeri in virgola mobile.integer: per i numeri interi.boolean: per valori veri o falsi.object: per dati strutturati con coppie chiave-valore.array: per gli elenchi di elementi.null: per consentire a una proprietà di essere null, includi"null"nell'array di tipi (ad es.{"type": ["string", "null"]}).
Queste proprietà descrittive aiutano a guidare il modello:
title: una breve descrizione di una proprietà.description: una descrizione più lunga e dettagliata di una proprietà.
Proprietà specifiche per tipo
Per i valori di object:
properties: un oggetto in cui ogni chiave è il nome di una proprietà e ogni valore è uno schema per quella proprietà.required: un array di stringhe che elenca le proprietà obbligatorie.additionalProperties: controlla se le proprietà non elencate inpropertiessono consentite. Può essere un valore booleano o uno schema.
Per i valori di string:
enum: elenca un insieme specifico di possibili stringhe per le attività di classificazione.format: specifica una sintassi per la stringa, ad esempiodate-time,date,time.
Per i valori number e integer:
enum: elenca un insieme specifico di valori numerici possibili.minimum: il valore inclusivo minimo.maximum: il valore inclusivo massimo.
Per i valori di array:
items: definisce lo schema per tutti gli elementi dell'array.prefixItems: definisce un elenco di schemi per i primi N elementi, consentendo strutture simili a tuple.minItems: il numero minimo di elementi nell'array.maxItems: il numero massimo di elementi nell'array.
Output strutturati e chiamata di funzione
| Funzionalità | Caso d'uso principale |
|---|---|
| Output strutturati | Formattazione della risposta finale. Da usare quando vuoi che la risposta del modello sia in un formato specifico. |
| Chiamata di funzione | Eseguire azioni durante la conversazione. Utilizza questo prompt quando il modello deve chiederti di eseguire un'attività prima di fornire una risposta finale. |
Best practice
- Descrizioni chiare:utilizza il campo
descriptionper guidare il modello. - Tipizzazione forte:utilizza tipi specifici (
integer,string,enum). - Ingegneria dei prompt:indica chiaramente cosa vuoi che faccia il modello.
- Convalida:anche se l'output è un JSON sintatticamente corretto, convalida sempre i valori nella tua applicazione.
- Gestione degli errori:implementa una gestione degli errori efficace per gli output conformi allo schema, ma semanticamente errati.
Limitazioni
- Sottoinsieme dello schema:non tutte le funzionalità di JSON Schema sono supportate.
- Complessità dello schema:gli schemi molto grandi o nidificati in profondità potrebbero essere rifiutati.