Generate streaming text by using a Claude model from Anthropic

Use the Anthropic Vertex AI SDK to send a prompt to an Anthropic Claude model and then output the streaming text.

Explore further

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

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]'

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

from anthropic import AnthropicVertex

client = AnthropicVertex(project_id=PROJECT_ID, region="us-east5")
result = []

with client.messages.stream(
    model="claude-3-5-sonnet-v2@20241022",
    max_tokens=1024,
    messages=[
        {
            "role": "user",
            "content": "Send me a recipe for banana bread.",
        }
    ],
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)
        result.append(text)

# Example response:
# Here's a simple recipe for delicious banana bread:
# Ingredients:
# - 2-3 ripe bananas, mashed
# - 1/3 cup melted butter
# ...
# ...
# 8. Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
# 9. Let cool in the pan for a few minutes, then remove and cool completely on a wire rack.

What's next

To search and filter code samples for other Google Cloud products, see the Google Cloud sample browser.