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Configuration variables - AWS SDK for Python
aws_credentials_identity_resolverendpoint_uriinterceptorsmax_attemptsregionretry_moderetry_strategysdk_ua_app_idtransportuser_agent_extra

Developer Preview — This documentation covers the AWS SDK for Python, which is in Developer Preview and intended for evaluation and testing only. Do not use it for production workloads. For production applications, use the AWS SDK for Python (Boto3). To understand the differences between the two SDKs, see Choosing the right AWS SDK for Python.

Configuration variables

This page lists all configuration variables supported by the AWS SDK for Python, including their default values and usage examples where applicable.

aws_credentials_identity_resolver

An IdentityResolver that resolves AWS credentials for request authentication. Set this field only to use a specific resolver instead of the default credential resolver chain. For more information, see Credential providers.

Default None (the client uses the default credential resolver chain)
Valid values IdentityResolver[AWSCredentialsIdentity, AWSIdentityProperties]

To provide static credentials directly, see Configure static credentials.

endpoint_uri

A custom endpoint URL to use instead of the standard AWS regional endpoint.

Env var AWS_ENDPOINT_URL (global), AWS_ENDPOINT_URL_<SERVICE_ID> (service-specific)
Profile key endpoint_url
Default None (uses standard regional endpoint)

Service-specific configs resolve this with extended precedence. See Service-specific endpoint resolution.

# Environment variable — global (applies to all services)
export AWS_ENDPOINT_URL=http://localhost:4566

# Environment variable — service-specific
export AWS_ENDPOINT_URL_BEDROCK_RUNTIME=http://localhost:5000
# Config file
[default]
endpoint_url = http://localhost:4566

interceptors

A list of interceptor hooks that are called at various points during request execution. Interceptors can inspect or modify requests and responses.

Default [] (empty list)

max_attempts

An integer representing the maximum number of attempts made for a single request, including the initial attempt. For example, setting this value to 5 results in a request being retried up to 4 times. If not provided, the number of retries defaults to whatever is modeled, which is typically 3 in the standard retry mode.

Env var AWS_MAX_ATTEMPTS
Profile key max_attempts
Default None (the retry strategy uses its own default, typically 3 for standard mode)
Valid values Positive integer (>= 1) 
# Environment variable
export AWS_MAX_ATTEMPTS=5
# Config file
[default]
max_attempts = 5

region

The AWS Region to send requests to.

Env vars AWS_REGION, AWS_DEFAULT_REGION
Profile key region
Default None
Valid values AWS Region identifiers like us-east-1, eu-west-1, ap-southeast-1 
# Environment variable
export AWS_REGION=us-west-2
# Config file
[default]
region = us-west-2
# Explicit override
config = await AsyncBedrockRuntimeConfig.resolve(region="us-west-2")

retry_mode

A string that represents the type of retries the SDK performs.

Env var AWS_RETRY_MODE
Profile key retry_mode
Default "standard"
Valid values "standard". Values "legacy" and "adaptive" from environment variables or config files are accepted but mapped to "standard" with a warning.

  • standard: a standardized set of retry rules across the AWS SDKs. This includes a standard set of errors that are retried and support for retry quotas, which limit the number of unsuccessful retries the SDK can make. This mode will default the maximum number of attempts to 3 unless a max_attempts is explicitly provided.

  • legacy: not supported in this SDK. If set, it maps to "standard" with a warning.

  • adaptive: not supported at the moment. If set, it maps to "standard" with a warning.

# Environment variable
export AWS_RETRY_MODE=standard
# Config file
[default]
retry_mode = standard

retry_strategy

An explicit retry strategy instance that bypasses retry_mode and max_attempts entirely. Use this when you need full control over retry behavior.

Default None (uses retry_mode/max_attempts to construct a strategy)

sdk_ua_app_id

An optional application-specific identifier that can be set. When set, it is appended to the SDK's User-Agent header, allowing you to identify your application in AWS service logs.

Env var AWS_SDK_UA_APP_ID
Profile key sdk_ua_app_id
Default None
Valid values Any string 
# Environment variable
export AWS_SDK_UA_APP_ID=my-web-app
# Config file
[default]
sdk_ua_app_id = my-web-app

transport

The HTTP client that the SDK uses to send requests. For details, including the optional AWSCRTHTTPClient and custom HTTP clients, see the HTTP configuration page.

Default AIOHTTPClient

user_agent_extra

An additional string appended to the User-Agent header.

Default None