## 1.9.0 (2026-09-28)
Full Changelog: [v1.8.0...v1.9.0](https://github.com/anthropics/anthropic-sdk-python/compare/v1.8.0...v1.9.0)
### Features
* **api:** add between_tools thinking type ([a9a577d](https://github.com/anthropics/anthropic-sdk-python/commit/a9a577d5a98cb2e133c1f8362f69fff856808da1))
* **api:** add claude-sonnet-5-5 ([a5a25e9](https://github.com/anthropics/anthropic-sdk-python/commit/a5a25e9e35ac32f100149d1dfa0fbf8cac42a8b4))
* **api:** add include_inherited and source to workspace rate limits ([0bf4af8](https://github.com/anthropics/anthropic-sdk-python/commit/0bf4af824331c424a03d9f486de2f53a656d3bba))
* **api:** add typed event type values to the Managed Agents events list filter ([1b82cd9](https://github.com/anthropics/anthropic-sdk-python/commit/1b82cd91ddd0874fb59a020fabc76618cb036ced))
* **api:** cache diagnostics GA — diagnostics on Message / MessageCreateParams ([22062b8](https://github.com/anthropics/anthropic-sdk-python/commit/22062b8fd130d3f90159845c1bde444ba1887f37))
* **tools:** optionally run tool calls while the reply streams ([26d0812](https://github.com/anthropics/anthropic-sdk-python/commit/26d08121bc80427665834f1b3fe767f813b4e4a4))
### Bug Fixes
* **client:** send no placeholder filename for unnamed file uploads ([9e9709d](https://github.com/anthropics/anthropic-sdk-python/commit/9e9709d7dc4202953a1935e8930b0f0fd80fa8b6))
* **helpers:** degrade between_tools thinking to disabled on fallback hops ([#952](https://github.com/anthropics/anthropic-sdk-python/issues/952)) ([a3834d4](https://github.com/anthropics/anthropic-sdk-python/commit/a3834d4cd849bc6a01a2bf4e292c5cd3893e1ca9))
* **messages:** accept diagnostics in stream() and parse() ([#929](https://github.com/anthropics/anthropic-sdk-python/issues/929)) ([fad840c](https://github.com/anthropics/anthropic-sdk-python/commit/fad840c2eeea413df35df8f79d41b92922c8ee89))
### Chores
* **api:** list the known model ids first in the Model types ([e5a082a](https://github.com/anthropics/anthropic-sdk-python/commit/e5a082a709950d2cbcc8add3351172942bcfaee5))
* **ci:** choose the CI runner by repository ([39ccf62](https://github.com/anthropics/anthropic-sdk-python/commit/39ccf62b127348f5ac8f3a78e6c1896aaa7cb746))
* **client:** stop sending beta header from parse and tool runner ([#907](https://github.com/anthropics/anthropic-sdk-python/issues/907)) ([1428100](https://github.com/anthropics/anthropic-sdk-python/commit/142810093d685841e6058b8c6cf61e4c449fc2a1))
* **docs:** clarify that stream: true returns the raw event stream ([82918fa](https://github.com/anthropics/anthropic-sdk-python/commit/82918fa9eb24d9d6bc63dcba23f9db396f4fd769))
* **docs:** make Managed Agents actor descriptions resource-neutral ([34ef524](https://github.com/anthropics/anthropic-sdk-python/commit/34ef5243ca062d7878f4c673503c57c84dfdbaa2))
* **docs:** restore the research-preview notice on the Dream type ([f03e32e](https://github.com/anthropics/anthropic-sdk-python/commit/f03e32e0d5e5a8df05f5966e0fcba0fd23845a00))
### Documentation
* add field docstring spacing rule to CLAUDE.md ([e5c35f4](https://github.com/anthropics/anthropic-sdk-python/commit/e5c35f4a70c38289286e16fe3d5e4ef0d3a3731a))
* **api:** prefer each field's own description over its shared type's ([d79a2e7](https://github.com/anthropics/anthropic-sdk-python/commit/d79a2e75c2b36f3620c6eb2c646de827da80b9d1))
* **claude.md:** add function body spacing rule ([3174f8f](https://github.com/anthropics/anthropic-sdk-python/commit/3174f8f4215edefa2dfe5d895ae003c292c5dd2a))
* list importable type names in api.md ([56a42ab](https://github.com/anthropics/anthropic-sdk-python/commit/56a42ab6ecca901939d41f1604bd98c162d52def))
▸ 主项目介绍 · anthropics/anthropic-sdk-python
▸ README 原文（同步于 2026-07-19 13:24）
# Claude SDK for Python
[](https://pypi.org/project/anthropic/)
The Claude SDK for Python provides access to the [Claude API](https://docs.anthropic.com/en/api/) from Python applications.
## Documentation
Full documentation is available at **[platform.claude.com/docs/en/api/sdks/python](https://platform.claude.com/docs/en/api/sdks/python)**.
## Installation
```sh
pip install anthropic
```
## Getting started
```python
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-4-6",
)
print(message.content)
```
## Requirements
Python 3.9+
## Contributing
See [CONTRIBUTING.md](./CONTRIBUTING.md).
## License
This project is licensed under the MIT License. See the [LICENSE](LICENSE) file for details.