anthropic

library1.0.0pypypi✓ verified 27d ago

Official Python SDK for the Anthropic API providing access to Claude models. Current version is 0.84.0 (Feb 2026). Releases approximately weekly. Two separate packages exist: anthropic (core SDK) and claude-agent-sdk-python (agent workflows).

llm-agents ai-ml

pip install anthropic

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · ANTHROPIC

anthropic

llm-agentspythonv1.0.0

Install

—

Import

—

Disk

—

Pass rate

0/ 10

Env Coverage0 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.0.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

glibc

py 3.10

10/12 runs

py 3.11

10/12 runs

py 3.12

10/12 runs

py 3.13

10/12 runs

py 3.9

6/12 runs

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Anthropic

✓ from anthropic import Anthropic

✗ import anthropic; anthropic.Client(api_key=...)

anthropic.Client is the old pre-0.3 API. Removed. Always use Anthropic() class.

AsyncAnthropic

✓ from anthropic import AsyncAnthropic

✗ import anthropic; anthropic.AsyncClient()

Use AsyncAnthropic for async contexts, not the legacy async client.

Minimal message call using the Anthropic SDK 0.84.x.

from anthropic import Anthropic client = Anthropic() # reads ANTHROPIC_API_KEY from env message = client.messages.create( model='claude-opus-4-6', max_tokens=1024, messages=[ {"role": "user", "content": "Hello, Claude"} ] ) print(message.content[0].text)

Debug

Known issues

breakinganthropic.Client() is removed. Use anthropic.Anthropic() instead.

fix

client = Anthropic(api_key=os.environ.get('ANTHROPIC_API_KEY'))

affects: < 0.3.0

gotchaSDK releases weekly. Pin your version in production or expect frequent behaviour changes.

fix

Pin with anthropic==0.84.0 in requirements.txt

affects: all

gotchamessage.content is a list, not a string. Access text via message.content[0].text.

fix

print(message.content[0].text) not print(message.content)

affects: all

gotchamax_tokens is required. No default value. Omitting raises a validation error.

fix

Always pass max_tokens=1024 or appropriate value

affects: all

deprecatedclaude-agent-sdk-python no longer requires Claude Code to be installed separately. It is bundled.

fix

Remove any separate Claude Code install steps from your setup.

affects: all

breakingThe package `claude-agent-sdk` is not a valid PyPI package and cannot be found. If you are trying to install the main Anthropic SDK, use `anthropic`. If you are looking for an agent-specific SDK, you might be looking for `claude-agent-sdk-python`.

fix

Replace `claude-agent-sdk` with `anthropic` or `claude-agent-sdk-python` in your requirements/install commands.

affects: all

breakingFailed to authenticate due to missing API key. Ensure `api_key` is passed during client initialization or set the `ANTHROPIC_API_KEY` environment variable.

fix

client = Anthropic(api_key=os.environ.get('ANTHROPIC_API_KEY'))

affects: all

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'anthropic'

The 'anthropic' package is not installed in the Python environment.

fix

Install the package using 'pip install anthropic'.

ImportError: cannot import name 'Anthropic' from 'anthropic'

The import statement is incorrect; 'Anthropic' is not a valid import from the 'anthropic' package.

fix

Use 'from anthropic import AnthropicClient' instead.

AttributeError: module 'anthropic' has no attribute 'Anthropic'

The 'Anthropic' class does not exist in the 'anthropic' module.

fix

Instantiate the client with 'client = anthropic.AnthropicClient()'.

TypeError: __init__() missing 1 required positional argument: 'api_key'

The 'AnthropicClient' class requires an 'api_key' argument during initialization.

fix

Initialize with 'client = anthropic.AnthropicClient(api_key="your_api_key")'.

ValueError: Invalid API key provided

The provided API key is incorrect or malformed.

fix

Ensure the API key is correct and properly formatted.

Upgrade

Version history

1.0.0latest on PyPI · released Aug 20, 2026

Audit

Dependencies

claude-agent-sdkoptionalRequired for multi-agent workflows with Claude. Separate from core anthropic package.

anthropic[bedrock]optionalRequired for AWS Bedrock access.

anthropic[vertex]optionalRequired for Google Vertex AI access.

Agent activity

84 hits · last 30 days

node

Anthropic

OpenAI (training)

Resources

githubhttps://github.com/anthropics/anthropic-sdk-python ↗

packagehttps://pypi.org/project/anthropic/ ↗

homepagehttps://www.anthropic.com ↗