xAI

Install

To use XaiModel, you need to either install pydantic-ai, or install pydantic-ai-slim with the xai optional group:

pipuv

pip install "pydantic-ai-slim[xai]"

uv add "pydantic-ai-slim[xai]"

Configuration

To use xAI models from xAI through their API, go to console.x.ai to create an API key.

docs.x.ai contains a list of available xAI models.

Environment variable

Once you have the API key, you can set it as an environment variable:

export XAI_API_KEY='your-api-key'

You can then use XaiModel by name:

from pydantic_ai import Agent

agent = Agent('xai:grok-4-1-fast-non-reasoning')
...

Or initialise the model directly:

from pydantic_ai import Agent
from pydantic_ai.models.xai import XaiModel

# Uses XAI_API_KEY environment variable
model = XaiModel('grok-4-1-fast-non-reasoning')
agent = Agent(model)
...

You can also customize the XaiModel with a custom provider:

from pydantic_ai import Agent
from pydantic_ai.models.xai import XaiModel
from pydantic_ai.providers.xai import XaiProvider

# Custom API key
provider = XaiProvider(api_key='your-api-key')
model = XaiModel('grok-4-1-fast-non-reasoning', provider=provider)
agent = Agent(model)
...

Or with a custom xai_sdk.AsyncClient:

from xai_sdk import AsyncClient

from pydantic_ai import Agent
from pydantic_ai.models.xai import XaiModel
from pydantic_ai.providers.xai import XaiProvider

xai_client = AsyncClient(api_key='your-api-key')
provider = XaiProvider(xai_client=xai_client)
model = XaiModel('grok-4-1-fast-non-reasoning', provider=provider)
agent = Agent(model)
...