Claude on Amazon Bedrock (legacy)

Calling Claude through Bedrock slightly differs from how you would call Claude when using Anthropic's client SDKs. This guide walks you through completing an API call to Claude on Bedrock using one of Anthropic's client SDKs.

Note that this guide assumes you have already signed up for an AWS account and configured programmatic access.

Install and configure the AWS CLI

1. Install a version of the AWS CLI at or newer than version 2.13.23
2. Configure your AWS credentials using the AWS configure command (see Configure the AWS CLI) or find your credentials by navigating to "Command line or programmatic access" within your AWS dashboard and following the directions in the popup modal.
3. Verify that your credentials are working:

aws sts get-caller-identity

Install an SDK for accessing Bedrock

Anthropic's client SDKs support Bedrock. You can also use an AWS SDK like boto3 directly.

Accessing Bedrock

Subscribe to Anthropic models

Go to the AWS Console > Bedrock > Model Access and request access to Anthropic models. Note that Anthropic model availability varies by region. See AWS documentation for latest information.

API model IDs

For more information about regional vs global model IDs, see the Global vs regional endpoints section below.

List available models

The following examples show how to print a list of all the Claude models available through Bedrock:

import boto3

bedrock = boto3.client(service_name="bedrock")
response = bedrock.list_foundation_models(byProvider="anthropic")

for summary in response["modelSummaries"]:
    print(summary["modelId"])

Making requests

The following examples show how to generate text from Claude on Bedrock:

from anthropic import AnthropicBedrock

client = AnthropicBedrock(
    # Authenticate by either providing the keys below or use the default AWS credential providers, such as
    # using ~/.aws/credentials or the "AWS_SECRET_ACCESS_KEY" and "AWS_ACCESS_KEY_ID" environment variables.
    aws_access_key="<access key>",
    aws_secret_key="<secret key>",
    # Temporary credentials can be used with aws_session_token.
    # Read more at https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp.html.
    aws_session_token="<session_token>",
    # aws_region changes the aws region to which the request is made. By default, we read AWS_REGION,
    # and if that's not present, we default to us-east-1. Note that we do not read ~/.aws/config for the region.
    aws_region="us-west-2",
)

message = client.messages.create(
    model="global.anthropic.claude-opus-4-6-v1",
    max_tokens=256,
    messages=[{"role": "user", "content": "Hello, world"}],
)
print(message.content)

See the client SDKs for more details, and the official Bedrock documentation.

Bearer token authentication

You can authenticate with Bedrock using bearer tokens instead of AWS credentials. This is useful in corporate environments where teams need access to Bedrock without managing AWS credentials, IAM roles, or account-level permissions.

The simplest approach is to set the AWS_BEARER_TOKEN_BEDROCK environment variable, which is automatically detected by fromEnv() credential resolution.

To provide a token programmatically:

using Anthropic.Bedrock;
using Anthropic.Models.Messages;

var client = new AnthropicBedrockClient(
    new AnthropicBedrockApiTokenCredentials
    {
        BearerToken = "your-bearer-token",
        Region = "us-east-1",
    }
);

var response = await client.Messages.Create(new MessageCreateParams
{
    Model = "us.anthropic.claude-sonnet-4-5-20250929-v1:0",
    MaxTokens = 1024,
    Messages = [new() { Role = Role.User, Content = "Hello!" }],
});

Activity logging

Bedrock provides an invocation logging service that allows customers to log the prompts and completions associated with your usage.

Anthropic recommends that you log your activity on at least a 30-day rolling basis in order to understand your activity and investigate any potential misuse.

Feature support

For all currently supported features on Bedrock, see API features overview.

PDF support on Bedrock

PDF support is available on Amazon Bedrock through both the Converse API and InvokeModel API. For detailed information about PDF processing capabilities and limitations, see the PDF support documentation.

Important considerations for Converse API users:

• Visual PDF analysis (charts, images, layouts) requires citations to be enabled
• Without citations, only basic text extraction is available
• For full control without forced citations, use the InvokeModel API

For more details on the two document processing modes and their limitations, refer to the PDF support guide.

Context window

Claude Opus 4.6 and Claude Sonnet 4.6 have a 1M-token context window on Amazon Bedrock. Other Claude models, including Sonnet 4.5 and Sonnet 4 (deprecated), have a 200k-token context window.

Amazon Bedrock limits request payloads to 20 MB. When sending large documents or many images, you may reach this limit before the token limit.

Global vs regional endpoints

Starting with Claude Sonnet 4.5 and all future models, Amazon Bedrock offers two endpoint types:

• Global endpoints: Dynamic routing for maximum availability
• Regional endpoints: Guaranteed data routing through specific geographic regions

Regional endpoints include a 10% pricing premium over global endpoints.

When to use each option

Global endpoints (recommended):

• Provide maximum availability and uptime
• Dynamically route requests to regions with available capacity
• No pricing premium
• Best for applications where data residency is flexible

Regional endpoints (CRIS):

• Route traffic through specific geographic regions
• Required for data residency and compliance requirements
• Available for US, EU, Japan, and Australia
• 10% pricing premium reflects infrastructure costs for dedicated regional capacity

Implementation

Using global endpoints (default for Opus 4.6, Sonnet 4.5, and Sonnet 4 (deprecated)):

The model IDs for Claude Sonnet 4.5 and 4 (deprecated) already include the global. prefix:

from anthropic import AnthropicBedrock

client = AnthropicBedrock(aws_region="us-west-2")

message = client.messages.create(
    model="global.anthropic.claude-opus-4-6-v1",
    max_tokens=256,
    messages=[{"role": "user", "content": "Hello, world"}],
)

Using regional endpoints (CRIS):

To use regional endpoints, remove the global. prefix from the model ID:

from anthropic import AnthropicBedrock

client = AnthropicBedrock(aws_region="us-west-2")

# Using US regional endpoint (CRIS)
message = client.messages.create(
    model="anthropic.claude-opus-4-6-v1",  # No global. prefix
    max_tokens=256,
    messages=[{"role": "user", "content": "Hello, world"}],
)

Additional resources

• AWS Bedrock pricing: aws.amazon.com/bedrock/pricing
• AWS pricing documentation: Bedrock pricing guide
• AWS blog post: Introducing Claude Sonnet 4.5 in Amazon Bedrock
• Anthropic pricing details: Pricing documentation