Claude Platform on AWS Provider / Claude Code v2.1.90

What

Claude Code now supports "Claude Platform on AWS" as a first-class API provider, alongside Bedrock, Vertex, and Foundry.

Usage

CLAUDE_CODE_USE_ANTHROPIC_AWS=1 claude

Details

Set CLAUDE_CODE_USE_ANTHROPIC_AWS=1 to enable the provider
Requires ANTHROPIC_AWS_WORKSPACE_ID (or workspaceId in constructor)
Optionally set ANTHROPIC_AWS_BASE_URL or let it derive from AWS_REGION / AWS_DEFAULT_REGION (pattern: https://aws-external-anthropic.{region}.api.aws)
Supports AWS SigV4 request signing via @aws-sdk/credential-providers
Supports explicit credentials via awsAccessKey + awsSecretAccessKey, AWS profile, or a custom providerChainResolver
Set CLAUDE_CODE_SKIP_ANTHROPIC_AWS_AUTH=1 to skip authentication (for development/testing)
Fast mode is not available on this provider (same as Bedrock, Vertex, and Foundry)

Evidence

AnthropicAws client class (search for "Claude Platform on AWS" and "ANTHROPIC_AWS_WORKSPACE_ID")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

The build it came inv2.1.90

1 Apr 2026 · 16 entries, this one is #2.

Either side of it

Open the release →

Names in this entry

envCLAUDE_CODE_USE_ANTHROPIC_AWS
A new provider-managed env var list decides gateway sign-in error wording.
envANTHROPIC_AWS_WORKSPACE_ID
Required for Claude Platform on AWS. Sent on every request as the anthropic-workspace-id header
envANTHROPIC_AWS_BASE_URL
Override the Claude Platform on AWS endpoint URL. Use for custom regions or when routing through an LLM gateway. Defaults to https://aws-external-anthropic.{region}.api.aws. Claude Code resolves the region with the same precedence as on Amazon Bedrock
envAWS_REGION
Bedrock no longer refuses to start when no region or base URL is configured.
envAWS_DEFAULT_REGION
Bedrock no longer refuses to start when no region or base URL is configured.
settingregion
Screenshots can zoom into a rectangle, but the documented image scale option is not exposed in this build.
envCLAUDE_CODE_SKIP_ANTHROPIC_AWS_AUTH
When true, the Claude Platform on AWS client (CLAUDE_CODE_USE_ANTHROPIC_AWS) does not look up AWS credentials: an Authorization header in the client's default headers (for example from ANTHROPIC_CUSTOM_HEADERS) is kept and also used as the API key with a leading Bearer stripped, and without such a header the client is created with skipAuth. At startup it also skips running the configured awsAuthRefresh and awsCredentialExport helpers, and the status panel shows Claude Platform on AWS auth skipped.

Is this right?

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.