**Experimental**: This documentation covers the AWS SDK for Python v4, which is experimental, non-GA software intended for evaluation and testing only. Do not use it for production workloads. For production applications, use the [AWS SDK for Python (Boto3)](https://docs.aws.amazon.com/boto3/latest/guide/quickstart.html). To understand the differences between the two SDKs, see [Choosing the right AWS SDK for Python](choosing-sdk.md).

# Configuration
<a name="configuring"></a>

The AWS SDK for Python v4 uses a configuration system that automatically discovers and resolves your AWS settings from multiple sources. When you create a client (`client = AsyncBedrockRuntimeClient()`), the SDK automatically resolves configuration values from your environment variables and AWS config files the first time an operation is called.

## Prerequisites
<a name="config-prerequisites"></a>

Before using the SDK, make sure you have the following configured:
+ An AWS Region, either set via the `AWS_REGION` environment variable, in your `~/.aws/config` file, or passed directly in code. Region is required and has no default.
+ AWS credentials available through a supported credential source (see [Credential providers](credential-providers.md)).

## Quick start
<a name="quick-start"></a>

The following example shows the simplest way to create a client and make a request. You do not need explicit configuration. The SDK resolves all configuration values automatically from your environment when the first operation is called:

```
import asyncio
from aws_sdk_bedrock_runtime.client import AsyncBedrockRuntimeClient
from aws_sdk_bedrock_runtime.models import Message, ContentBlockText, ConverseInput


async def main():

    async with AsyncBedrockRuntimeClient() as client:

        response = await client.converse(
            ConverseInput(
                model_id="global.amazon.nova-2-lite-v1:0",
                messages=[Message(role="user", content=[ContentBlockText(value="What is 2 + 2?")])],
            )
        )

        print(response.output.value.content[0].value)


asyncio.run(main())
```

This example assumes that `AWS_REGION` is set (or `region` is defined in your config file) and that credentials are available through the credential chain. When you run this, the SDK creates a client, resolves configuration on the first operation call, sends a request to Amazon Bedrock Runtime, and prints the response.

## Explicit configuration
<a name="explicit-configuration"></a>

You can either let the SDK resolve configuration automatically (as shown in [Quick start](#quick-start)), or explicitly resolve it for more control. Explicit resolution lets you override specific values and validate configuration upfront before any operation is called. See [Configuration resolution](config-resolution.md) for details.

## Next steps
<a name="config-next-steps"></a>
+ To understand how the SDK resolves configuration values, see [Configuration resolution](config-resolution.md).
+ To look up a specific configuration setting, see [Configuration variables](configuration-variables.md).
+ To set up profiles for different environments, see [Config files and named profiles](config-files.md).
+ To learn how the SDK finds credentials, see [Credential providers](credential-providers.md).
+ To configure or replace the HTTP client, see [HTTP configuration](http-configuration.md).
+ To understand how retries work and how to configure them, see [Retries](config-retries.md).