Use function calling with Anthropic to enhance the capabilities of Claude

Use function calling with Anthropic Claude to query external tools, such as the Google Places API. The sample calls the Text Search Places API directly from your Claude prompt to retrieve information about places based on a user's query.

Explore further

For detailed documentation that includes this code sample, see the following:

• Use Anthropic's Claude models

Code sample

Python

Before trying this sample, follow the Python setup instructions in the Vertex AI quickstart using client libraries. For more information, see the Vertex AI Python API reference documentation.

To authenticate to Vertex AI, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

# TODO(developer): Vertex AI SDK - uncomment below & run
# pip3 install --upgrade --user google-cloud-aiplatform
# gcloud auth application-default login
# pip3 install -U 'anthropic[vertex]'
from anthropic import AnthropicVertex

# TODO(developer): Update and un-comment below line
# PROJECT_ID = "your-project-id"

client = AnthropicVertex(project_id=PROJECT_ID, region="us-east5")
message = client.messages.create(
    model="claude-3-5-sonnet-v2@20241022",
    max_tokens=1024,
    tools=[
        {
            "name": "text_search_places_api",
            "description": "returns information about a set of places based on a string",
            "input_schema": {
                "type": "object",
                "properties": {
                    "textQuery": {
                        "type": "string",
                        "description": "The text string on which to search",
                    },
                    "priceLevels": {
                        "type": "array",
                        "description": "Price levels to query places, value can be one of [PRICE_LEVEL_INEXPENSIVE, PRICE_LEVEL_MODERATE, PRICE_LEVEL_EXPENSIVE, PRICE_LEVEL_VERY_EXPENSIVE]",
                    },
                    "openNow": {
                        "type": "boolean",
                        "description": "whether those places are open for business.",
                    },
                },
                "required": ["textQuery"],
            },
        }
    ],
    messages=[
        {
            "role": "user",
            "content": "What are some affordable and good Italian restaurants open now in San Francisco??",
        }
    ],
)
print(message.model_dump_json(indent=2))
# Example response:
# {
#   "id": "msg_vrtx_018pk1ykbbxAYhyWUdP1bJoQ",
#   "content": [
#     {
#       "text": "To answer your question about affordable and good Italian restaurants
#       that are currently open in San Francisco....
# ...

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