PydanticAI

Introduction

PydanticAI is a Python framework for building agentic applications with Generative AI — designed to make it far less painful to go from prototype to production.

GATE/0 integrates seamlessly with Pydantic AI, a framework for building structured LLM applications. Pydantic AI supports custom endpoints and API keys, allowing you to route all LLM traffic through GATE0 with minimal configuration.

Using GATE/0 with PydanticAI

Set up your OpenAI provider in GATE/0

Retrieve your OpenAI API key from OpenAI
Add a new OpenAI provider in GATE/0 here
Copy your GATE/0 API key from here

Install PydanticAI

pip install pydantic-ai

Configure the GATE/0 API key Set your GATE0 API key as an environment variable:

export GATE0_API_KEY=your-gate0-api-key

Implement your agent

from pydantic_ai import Agent, RunContext
from pydantic_ai.models.openai import OpenAIModel
from pydantic_ai.providers.openai import OpenAIProvider
from pydantic_ai.settings import ModelSettings
import os

provider = OpenAIProvider(
    api_key=os.environ.get("GATE0_API_KEY"), # API key provided by GATE0
    base_url="https://gateway.gate.io/v1" # GATE0 cloud proxy URL
)
model = OpenAIModel(
    'openai/gpt-4o', # Model name with provider prefix
    provider=provider
)

roulette_agent = Agent(  
    model=model,
    deps_type=int,
    output_type=bool,
    system_prompt=(
        'Use the `roulette_wheel` function to see if the '
        'customer has won based on the number they provide.'
    ),
    model_settings=ModelSettings(
        extra_headers={ # Custom labels
            'x-gate0-label-project': 'alpha', 
            'x-gate0-label-client': 'frontend', 
            'x-gate0-label-env': 'prod'
        }
    ),
)


@roulette_agent.tool
async def roulette_wheel(ctx: RunContext[int], square: int) -> str:  
    """check if the square is a winner"""
    return 'winner' if square == ctx.deps else 'loser'


# Run the agent
success_number = 18  
result = roulette_agent.run_sync('Put my money on square eighteen', deps=success_number)
print(result.output)  
#> True

result = roulette_agent.run_sync('I bet five is the winner', deps=success_number)
print(result.output)

Explanation of the implementation

An instance of OpenAIProvider is created with the base URL set to https://gateway.gate0.io/v1, using your GATE0 API key instead of the default OpenAI key.
An OpenAIModel is initialized with the provider and a prefixed model name. Make sure the model name is prefixed with the provider slug (e.g., use openai/gpt-4o instead of gpt-4o).
A ModelSettings instance is created with extra_headers to include custom labels — useful for resource allocation and cost tracking.
The model and model_settings objects are passed to the Agent constructor to finalize the setup.

PydanticAI

Introduction

Using GATE/0 with PydanticAI

Explanation of the implementation

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