[BUG] Claude Code returns 404 error for Bedrock cross-region inference profiles (us./global. prefix) despite valid model access

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

claude-code-bug-report.md

# Bedrock Cross-Region Inference Profile Returns 404 "Model use case details" Error

## Environment

- **Claude Code version**: 2.1.2
- **OS**: Linux (Ubuntu)
- **AWS Region**: us-east-1
- **Model ID**: `us.anthropic.claude-opus-4-5-20251101-v1:0`

## Description

Claude Code fails to invoke Bedrock models using cross-region inference profiles, returning a 404 error about "Model use case details", even though the same model works correctly via AWS CLI and other tools (Aider and Eh-I-DeCoder).

## Steps to Reproduce

1. Configure AWS credentials with Bedrock invoke permissions
2. Run Claude Code with Bedrock and cross-region inference profile:

```bash
CLAUDE_CODE_USE_BEDROCK=true AWS_REGION=us-east-1 claude --model global.anthropic.claude-opus-4-5-20251101-v1:0 -p "test"

Expected Behavior

Claude Code should successfully invoke the model and return a response.

Actual Behavior

API Error: 404 Model use case details have not been submitted for this account. Fill out the Anthropic use case details form before using the model. If you have already filled out the form, try again in 15 minutes.

Proof That Model Access Works

The same model invoked via AWS CLI succeeds:

aws bedrock-runtime invoke-model \
  --model-id us.anthropic.claude-opus-4-5-20251101-v1:0 \
  --region us-east-1 \
  --body '{"anthropic_version":"bedrock-2023-05-31","max_tokens":100,"messages":[{"role":"user","content":"Hello"}]}' \
  --content-type application/json \
  --accept application/json \
  --cli-binary-format raw-in-base64-out \
  /tmp/response.json && cat /tmp/response.json

Response:

{
  "model": "claude-opus-4-5-20251101",
  "id": "msg_bdrk_01EH5dfKyBtkQdC11JV3A7Qj",
  "type": "message",
  "role": "assistant",
  "content": [{"type": "text", "text": "Hello! How are you doing today? Is there something I can help you with?"}],
  "stop_reason": "end_turn",
  "usage": {"input_tokens": 8, "output_tokens": 20}
}

Additionally, Aider works with the same credentials and model:

AWS_REGION=us-east-1 aider-server --model bedrock/converse/global.anthropic.claude-opus-4-5-20251101-v1:0

Available Inference Profiles

The cross-region inference profile is confirmed active:

{
  "inferenceProfileName": "US Anthropic Claude Opus 4.5",
  "inferenceProfileId": "us.anthropic.claude-opus-4-5-20251101-v1:0",
  "status": "ACTIVE",
  "type": "SYSTEM_DEFINED",
  "models": [
    {"modelArn": "arn:aws:bedrock:us-east-1::foundation-model/anthropic.claude-opus-4-5-20251101-v1:0"},
    {"modelArn": "arn:aws:bedrock:us-east-2::foundation-model/anthropic.claude-opus-4-5-20251101-v1:0"},
    {"modelArn": "arn:aws:bedrock:us-west-2::foundation-model/anthropic.claude-opus-4-5-20251101-v1:0"}
  ]
}

Suspected Cause

Claude Code may be:

1. Not properly handling cross-region inference profile IDs (with us. or global. prefix)
2. Making an incorrect API call that doesn't use the Bedrock runtime invoke endpoint
3. Attempting to validate the model ID against a different endpoint that returns this error

Additional Context

• Settings file location: ~/.claude/settings.json
• IAM role has bedrock-runtime:InvokeModel permissions
• Same issue occurs with global.anthropic.claude-opus-4-5-20251101-v1:0

### What Should Happen?

## Expected Behavior

Claude Code should successfully invoke the model and return a response.

## Actual Behavior

API Error: 404 Model use case details have not been submitted for this account. Fill out the Anthropic use case details form before using the model. If you have already filled out the form, try again in 15 minutes.

### Error Messages/Logs

```shell
API Error: 404 Model use case details have not been submitted for this account. Fill out the Anthropic use case details form before using the model. If you have already filled out the form, try again in 15 minutes.

Steps to Reproduce

Steps to Reproduce

1. Configure AWS credentials with Bedrock invoke permissions
2. Run Claude Code with Bedrock and cross-region inference profile:

CLAUDE_CODE_USE_BEDROCK=true AWS_REGION=us-east-1 claude --model global.anthropic.claude-opus-4-5-20251101-v1:0 -p "test"

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.2

Platform

AWS Bedrock

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

_No response_