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Anthropic

Install

To use AnthropicModel models, you need to either install pydantic-ai, or install pydantic-ai-slim with the anthropic optional group:

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

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

Configuration

To use Anthropic through their API, go to console.anthropic.com/settings/keys to generate an API key.

AnthropicModelName contains a list of available Anthropic models.

Environment variable

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

export ANTHROPIC_API_KEY='your-api-key'

You can then use AnthropicModel by name:

from pydantic_ai import Agent

agent = Agent('anthropic:claude-3-5-sonnet-latest')
...

Or initialise the model directly with just the model name:

from pydantic_ai import Agent
from pydantic_ai.models.anthropic import AnthropicModel

model = AnthropicModel('claude-3-5-sonnet-latest')
agent = Agent(model)
...

provider argument

You can provide a custom Provider via the provider argument:

from pydantic_ai import Agent
from pydantic_ai.models.anthropic import AnthropicModel
from pydantic_ai.providers.anthropic import AnthropicProvider

model = AnthropicModel(
    'claude-3-5-sonnet-latest', provider=AnthropicProvider(api_key='your-api-key')
)
agent = Agent(model)
...

Custom HTTP Client

You can customize the AnthropicProvider with a custom httpx.AsyncClient:

from httpx import AsyncClient

from pydantic_ai import Agent
from pydantic_ai.models.anthropic import AnthropicModel
from pydantic_ai.providers.anthropic import AnthropicProvider

custom_http_client = AsyncClient(timeout=30)
model = AnthropicModel(
    'claude-3-5-sonnet-latest',
    provider=AnthropicProvider(api_key='your-api-key', http_client=custom_http_client),
)
agent = Agent(model)
...