Claude SDK for Python

The Claude SDK for Python provides access to the Claude API from Python applications.

Documentation

Tool helpers (@beta_tool, the tool runner and ToolError) are documented in tools.md. The browser and computer toolset classes have their own guides, browser-toolset.md and computer-toolset.md.

Full documentation is available at platform.claude.com/docs/en/api/sdks/python.

Installation

pip install anthropic

Upgrading from a 0.x release? See the v1 migration guide.

Getting started

import os
from anthropic import Anthropic

client = Anthropic(
    api_key=os.environ.get("ANTHROPIC_API_KEY"),  # This is the default and can be omitted
)

message = client.messages.create(
    max_tokens=1024,
    messages=[
        {
            "role": "user",
            "content": "Hello, Claude",
        }
    ],

    model="claude-opus-5-5",
)

print(message.content)

OpenTelemetry

The SDK reports each API call as an OpenTelemetry span when your application has registered a tracer provider. It depends on opentelemetry-api, a required dependency, and never on an OpenTelemetry SDK.

# a provider other than the registered one
client = Anthropic(open_telemetry={"tracer_provider": tracer_provider})
# no spans
quiet = Anthropic(open_telemetry=False)
# adds prompts and completions
verbose = Anthropic(open_telemetry={"traces": {"content_mode": "content"}})
# keeps the content of one span within this size
bounded = Anthropic(
    open_telemetry={"traces": {"content_mode": "content", "max_content_bytes": 65_536}}
)
# sends no trace context headers, for an application whose HTTP client instrumentation already sends them, so that
# a request does not carry them twice
unpropagated = Anthropic(open_telemetry={"propagation": False})

# sets gen_ai.conversation.id on the spans of one conversation's requests. with_options replaces the whole option,
# so start from client.open_telemetry, which has the client's
conversation = client.with_options(
    open_telemetry={**client.open_telemetry, "conversation_id": conversation_id}
)
conversation.messages.create(...)

A client that is given no open_telemetry option reads these environment variables when it is constructed: ANTHROPIC_OPEN_TELEMETRY=false turns its spans off, ANTHROPIC_OPEN_TELEMETRY_TRACES_CONTENT_MODE=content adds prompts and completions, ANTHROPIC_OPEN_TELEMETRY_TRACES_MAX_CONTENT_BYTES sets max_content_bytes, and ANTHROPIC_OPEN_TELEMETRY_PROPAGATION=false sends no trace context headers. A client that is given the option, even {} or a tracer_provider alone, reads none of them: what the option leaves out has its default (spans on, trace context headers sent, no prompts or completions, 750,000 bytes). A copy made with with_options or copy keeps its client's option unless it is given its own.

Requirements

Python 3.10+

Contributing

See CONTRIBUTING.md.

License

This project is licensed under the MIT License. See the LICENSE file for details.