# Copyright 2026 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
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# SPDX-License-Identifier: Apache-2.0
"""Pydantic models shared between REST request validation and Genkit flow schemas.
All input models include ``Field`` constraints (``max_length``,
``min_length``, ``ge``/``le``, ``pattern``) so that Pydantic rejects
malformed input before it reaches any flow or LLM call. This is a
defense-in-depth layer on top of the ``MaxBodySizeMiddleware``.
"""
from pydantic import BaseModel, Field
class JokeInput(BaseModel):
"""Input for the joke endpoint."""
name: str = Field(
default="Mittens",
description="Subject of the joke",
max_length=200,
)
username: str | None = Field(
default=None,
description="Username for personalization",
max_length=200,
)
class JokeResponse(BaseModel):
"""Response from the joke endpoint."""
joke: str = Field(description="AI-generated joke")
username: str | None = Field(default=None, description="Username from Authorization header")
class TranslateInput(BaseModel):
"""Input for the translation endpoint."""
text: str = Field(
default=(
"The Northern Lights, or Aurora Borealis, are one of nature's most "
"spectacular displays. Charged particles from the Sun collide with "
"gases in Earth's atmosphere, creating shimmering curtains of green, "
"pink, and violet light that dance across the polar sky. For centuries, "
"cultures around the world have woven myths and legends around these "
"ethereal lights — the Vikings believed they were reflections of the "
"Valkyries' armor, while the Sámi people considered them the energies "
"of departed souls."
),
description="Text to translate",
min_length=1,
max_length=10_000,
)
target_language: str = Field(
default="French",
description="Target language",
max_length=100,
)
class TranslationResult(BaseModel):
"""Structured translation output — the model returns this directly."""
original_text: str = Field(description="Original input text")
translated_text: str = Field(description="Translated text")
target_language: str = Field(description="Language translated into")
confidence: str = Field(description="Confidence level: high, medium, or low")
class ImageInput(BaseModel):
"""Input for the image description endpoint."""
image_url: str = Field(
default="https://upload.wikimedia.org/wikipedia/commons/4/47/PNG_transparency_demonstration_1.png",
description="URL of the image to describe",
max_length=2048,
)
class ImageResponse(BaseModel):
"""Response from the image description endpoint."""
description: str = Field(description="Textual description of the image")
image_url: str = Field(description="URL of the image that was described")
class CharacterInput(BaseModel):
"""Input for RPG character generation."""
name: str = Field(
default="Luna",
description="Character name",
min_length=1,
max_length=200,
)
class Skills(BaseModel):
"""Core character stats for an RPG character."""
strength: int = Field(description="Strength (0-100)", ge=0, le=100)
charisma: int = Field(description="Charisma (0-100)", ge=0, le=100)
endurance: int = Field(description="Endurance (0-100)", ge=0, le=100)
class RpgCharacter(BaseModel):
"""Structured RPG character — returned directly by the model."""
name: str = Field(description="Name of the character")
back_story: str = Field(description="Character backstory", alias="backStory")
abilities: list[str] = Field(description="List of abilities (3-4)", max_length=10)
skills: Skills
class ChatInput(BaseModel):
"""Input for the chat endpoint."""
question: str = Field(
default="What is the best programming language?",
description="Question to ask the AI",
min_length=1,
max_length=5_000,
)
class ChatResponse(BaseModel):
"""Response from the chat endpoint."""
answer: str = Field(description="AI-generated answer")
persona: str = Field(default="pirate captain", description="Active persona")
class StoryInput(BaseModel):
"""Input for the streaming story endpoint."""
topic: str = Field(
default="a brave cat",
description="Topic for the story",
min_length=1,
max_length=1_000,
)
class CodeInput(BaseModel):
"""Input for the code generation endpoint."""
description: str = Field(
default="a Python function that checks if a number is prime",
description="Natural language description of the code to generate",
min_length=1,
max_length=10_000,
)
language: str = Field(
default="python",
description="Programming language (e.g. python, javascript, go, rust)",
max_length=50,
pattern=r"^[a-zA-Z#+]+$",
)
class CodeOutput(BaseModel):
"""Structured output from code generation."""
code: str = Field(description="The generated source code")
language: str = Field(description="Programming language used")
explanation: str = Field(description="Brief explanation of the code")
filename: str = Field(description="Suggested filename (e.g. prime.py)")
class CodeReviewInput(BaseModel):
"""Input for the code review endpoint."""
code: str = Field(
default="def add(a, b):\n return a + b",
description="Source code to review",
min_length=1,
max_length=50_000,
)
language: str | None = Field(
default=None,
description="Programming language (auto-detected if omitted)",
max_length=50,
)
