anthropic 0.3.0

Client library for the anthropic API

Anthropic Python API Library

The Anthropic Python library provides convenient access to the Anthropic REST API from any Python 3.7+ application. It includes type definitions for all request params and response fields, and offers both synchronous and asynchronous clients powered by httpx.

Migration from v0.2.x and below

In v0.3.0, we introduced a fully rewritten SDK.

The new version uses separate sync and async clients, unified streaming, typed params and structured response objects, and resource-oriented methods:

Sync before/after:

- client = anthropic.Client(os.environ["ANTHROPIC_API_KEY"])
+ client = anthropic.Anthropic(api_key=os.environ["ANTHROPIC_API_KEY"])
  # or, simply provide an ANTHROPIC_API_KEY environment variable:
+ client = anthropic.Anthropic();

- rsp = client.completion(**params)
- rsp["completion"]
+ rsp = client.completions.create(**params)
+ rsp.completion

Async before/after:

- client = anthropic.Client(os.environ["ANTHROPIC_API_KEY"])
+ client = anthropic.AsyncAnthropic(api_key=os.environ["ANTHROPIC_API_KEY"])

- await client.acompletion(**params)
+ await client.completions.create(**params)

The .completion_stream() and .acompletion_stream() methods have been removed; simply pass stream=Trueto .completions.create().

Streaming responses are now incremental; the full text is not sent in each message, as v0.3 sends the Anthropic-Version: 2023-06-01 header.

Example streaming diff

  import anthropic

- client = anthropic.Client(os.environ["ANTHROPIC_API_KEY"])
+ client = anthropic.Anthropic()

  # Streams are now incremental diffs of text
  # rather than sending the whole message every time:
  text = "
- stream = client.completion_stream(**params)
- for data in stream:
-     diff = data["completion"].replace(text, "")
-     text = data["completion"]
+ stream = client.completions.create(**params, stream=True)
+ for data in stream:
+     diff = data.completion # incremental text
+     text += data.completion
      print(diff, end="")

  print("Done. Final text is:")
  print(text)

Documentation

The API documentation can be found here.

Installation

pip install anthropic

Usage

from anthropic import Anthropic, HUMAN_PROMPT, AI_PROMPT

anthropic = Anthropic(
    # defaults to os.environ.get("ANTHROPIC_API_KEY")
    api_key="my api key",
)

completion = anthropic.completions.create(
    model="claude-1",
    max_tokens_to_sample=300,
    prompt=f"{HUMAN_PROMPT} how does a court case get to the Supreme Court? {AI_PROMPT}",
)
print(completion.completion)

While you can provide an api_key keyword argument, we recommend using python-dotenv and adding ANTHROPIC_API_KEY="my api key" to your .env file so that your API Key is not stored in source control.

Async Usage

Simply import AsyncAnthropic instead of Anthropic and use await with each API call:

from anthropic import Anthropic, HUMAN_PROMPT, AI_PROMPT

anthropic = AsyncAnthropic(
    # defaults to os.environ.get("ANTHROPIC_API_KEY")
    api_key="my api key",
)


async def main():
    completion = await anthropic.completions.create(
        model="claude-1",
        max_tokens_to_sample=300,
        prompt=f"{HUMAN_PROMPT} how does a court case get to the Supreme Court? {AI_PROMPT}",
    )
    print(completion.completion)


asyncio.run(main())

Functionality between the synchronous and asynchronous clients is otherwise identical.

Streaming Responses

We provide support for streaming responses using Server Side Events (SSE).

from anthropic import Anthropic, HUMAN_PROMPT, AI_PROMPT

anthropic = Anthropic()

stream = anthropic.completions.create(
    prompt=f"{HUMAN_PROMPT} Your prompt here {AI_PROMPT}",
    max_tokens_to_sample=300,
    model="claude-1",
    stream=True,
)
for completion in stream:
    print(completion.completion)

The async client uses the exact same interface.

from anthropic import Anthropic, HUMAN_PROMPT, AI_PROMPT

anthropic = AsyncAnthropic()

stream = await anthropic.completions.create(
    prompt=f"{HUMAN_PROMPT} Your prompt here {AI_PROMPT}",
    max_tokens_to_sample=300,
    model="claude-1",
    stream=True,
)
async for completion in stream:
    print(completion.completion)

Using Types

Nested request parameters are TypedDicts, while responses are Pydantic models. This helps provide autocomplete and documentation within your editor.

If you would like to see type errors in VS Code to help catch bugs earlier, set python.analysis.typeCheckingMode to "basic".

Handling errors

When the library is unable to connect to the API (e.g., due to network connection problems or a timeout), a subclass of anthropic.APIConnectionError is raised.

When the API returns a non-success status code (i.e., 4xx or 5xx response), a subclass of anthropic.APIStatusError will be raised, containing status_code and response properties.

All errors inherit from anthropic.APIError.

from anthropic import Anthropic, HUMAN_PROMPT, AI_PROMPT

anthropic = Anthropic()

try:
    anthropic.completions.create(
        prompt=f"{HUMAN_PROMPT} Your prompt here {AI_PROMPT}",
        max_tokens_to_sample=300,
        model="claude-1",
    )
except anthropic.APIConnectionError as e:
    print("The server could not be reached")
    print(e.__cause__)  # an underlying Exception, likely raised within httpx.
except anthropic.RateLimitError as e:
    print("A 429 status code was received; we should back off a bit.")
except anthropic.APIStatusError as e:
    print("Another non-200-range status code was received")
    print(e.status_code)
    print(e.response)

Error codes are as followed:

Status Code	Error Type
400	BadRequestError
401	AuthenticationError
403	PermissionDeniedError
404	NotFoundError
422	UnprocessableEntityError
429	RateLimitError
>=500	InternalServerError
N/A	APIConnectionError

Retries

Certain errors will be automatically retried 2 times by default, with a short exponential backoff. Connection errors (for example, due to a network connectivity problem), 409 Conflict, 429 Rate Limit, and >=500 Internal errors will all be retried by default.

You can use the max_retries option to configure or disable this:

from anthropic import Anthropic, HUMAN_PROMPT, AI_PROMPT

# Configure the default for all requests:
anthropic = Anthropic(
    # default is 2
    max_retries=0,
)

# Or, configure per-request:
anthropic.with_options(max_retries=5).completions.create(
    prompt=f"{HUMAN_PROMPT} Can you help me effectively ask for a raise at work? {AI_PROMPT}",
    max_tokens_to_sample=300,
    model="claude-1",
)

Timeouts

Requests time out after 60 seconds by default. You can configure this with a timeout option, which accepts a float or an httpx.Timeout:

from anthropic import Anthropic, HUMAN_PROMPT, AI_PROMPT

# Configure the default for all requests:
anthropic = Anthropic(
    # default is 60s
    timeout=20.0,
)

# More granular control:
anthropic = Anthropic(
    timeout=httpx.Timeout(60.0, read=5.0, write=10.0, connect=2.0),
)

# Override per-request:
anthropic.with_options(timeout=5 * 1000).completions.create(
    prompt=f"{HUMAN_PROMPT} Where can I get a good coffee in my neighbourhood? {AI_PROMPT}",
    max_tokens_to_sample=300,
    model="claude-1",
)

On timeout, an APITimeoutError is thrown.

Note that requests which time out will be retried twice by default.

Default Headers

We automatically send the anthropic-version header set to 2023-06-01.

If you need to, you can override it by setting default headers per-request or on the client object.

Be aware that doing so may result in incorrect types and other unexpected or undefined behavior in the SDK.

from anthropic import Anthropic

anthropic = Anthropic(
    default_headers={"anthropic-version": "My-Custom-Value"},
)

Advanced: Configuring custom URLs, proxies, and transports

You can configure the following keyword arguments when instantiating the client:

import httpx
from anthropic import Anthropic

anthropic = Anthropic(
    # Use a custom base URL
    base_url="http://my.test.server.example.com:8083",
    proxies="http://my.test.proxy.example.com",
    transport=httpx.HTTPTransport(local_address="0.0.0.0"),
)

See the httpx documentation for information about the proxies and transport keyword arguments.

Status

This package is in beta. Its internals and interfaces are not stable and subject to change without a major semver bump; please reach out if you rely on any undocumented behavior.

We are keen for your feedback; please open an issue with questions, bugs, or suggestions.

Requirements

Python 3.7 or higher.