[BUG] Version 2.1.69 breaks AWS Bedrock compatibility with `eager_input_streaming` error

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?

Summary

Claude Code VS Code extension version 2.1.69 introduces a breaking change that causes a 400 error when using AWS Bedrock. The extension sends an eager_input_streaming parameter that Bedrock's API doesn't support.

Environment

• Extension Version (broken): 2.1.69, 2.1.70, 2.1.71, 2.1.72
• Extension Version (working): 2.1.68
• API Provider: AWS Bedrock
• Model: us.anthropic.claude-sonnet-4-5-20250929-v1:0
• VS Code Version: (latest)
• OS: Windows 11 Enterprise 10.0.22631

What Should Happen?

Expected Behavior

Extension should work with AWS Bedrock as it did in version 2.1.68.

Actual Behavior

Extension fails with 400 error because it sends eager_input_streaming parameter in tools.0.custom which AWS Bedrock doesn't recognize

Error Messages/Logs

## Error Message

API Error: 400 {"error":{"message":"{"message":"tools.0.custom.eager_input_streaming: Extra inputs are not permitted"}. Received Model Group=us.anthropic.claude-sonnet-4-5-20250929-v1:0\nAvailable Model Group Fallbacks=None","type":"None","param":"None","code":"400"}}

Steps to Reproduce

Steps to Reproduce

1. Configure Claude Code extension to use AWS Bedrock endpoint
2. Use any version 2.1.69 or later
3. Start a conversation with Claude
4. Observe 400 error immediately

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.68

Claude Code Version

2.1.72

Platform

AWS Bedrock

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Analysis

Version 2.1.69 introduced the eager_input_streaming parameter as part of a streaming feature enhancement. While this works with Anthropic's direct API, AWS Bedrock's implementation of the Claude API doesn't support this parameter, causing all requests to fail.

Notably, the Claude CLI tool works fine because it likely uses an older version of the core that doesn't include this parameter, or it properly detects the Bedrock endpoint and omits incompatible features.

Workaround

Downgrade to version 2.1.68:

1. Open Extensions in VS Code
2. Find "Claude Code"
3. Click gear icon → "Install Another Version..."
4. Select version 2.1.68

Investigation Findings

• All CLI versions (2.1.50, 2.1.68, 2.1.69+) contain the eager_input_streaming code
• The feature appears to be enabled by default starting in version 2.1.69
• Attempted workaround using claudeCode.claudeProcessWrapper setting to use older CLI version did not resolve the issue
• This suggests the enabling logic is in the extension code or extension-CLI communication, not just the CLI itself

Suggested Fix

The extension/CLI should:

1. Detect when using AWS Bedrock endpoint (check model ID prefix us.anthropic or us.anthropic.*)
2. Disable or omit eager_input_streaming parameter for Bedrock endpoints
3. Add a compatibility check before sending Bedrock-incompatible parameters
4. Consider adding a setting to manually disable this feature for compatibility

Additional Context

• This affects all users using Claude via AWS Bedrock
• The issue was discovered after the extension auto-updated
• Log analysis confirms the parameter is being sent in API requests starting from version 2.1.69
• Binary analysis shows the feature code exists in all versions but is only enabled in 2.1.69+