Claude Code 2.1.69 Sends Unsupported Beta Header — API 400 Error Fix

What this error means

API error 400: The provider claude-4.5-opus does not support the advanced-tool-use-2025-11-20 beta header is a Claude Code failure pattern reported for developers trying to fix claude code api 400 error after upgrading to v2.1.69 caused by unsupported advanced-tool-use beta header. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue #30926 in anthropics/claude-code: Upgrading from v2.1.68 to v2.1.69 causes immediate API 400 error. The extension sends ‘advanced-tool-use-2025-11-20’ beta flag to endpoints that don’t support it. Reported as a single bug with preflight checklist completed.

Common causes

• Upgrading Claude Code from v2.1.68 to v2.1.69 causes an immediate API 400 error because the extension sends the ‘advanced-tool-use-2025-11-20’ beta header to models/endpoints that don’t support it. This completely breaks the tool for affected users and forces them to downgrade or wait for a patch.
• GitHub issue #30926 in anthropics/claude-code: Upgrading from v2.1.68 to v2.1.69 causes immediate API 400 error. The extension sends ‘advanced-tool-use-2025-11-20’ beta flag to endpoints that don’t support it. Reported as a single bug with preflight checklist completed.

Quick fixes

1. Confirm the exact error signature matches API error 400: The provider claude-4.5-opus does not support the advanced-tool-use-2025-11-20 beta header.
2. Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/anthropics/claude-code/issues/30926

Evidence note: GitHub issue #30926 in anthropics/claude-code: Upgrading from v2.1.68 to v2.1.69 causes immediate API 400 error. The extension sends ‘advanced-tool-use-2025-11-20’ beta flag to endpoints that don’t support it. Reported as a single bug with preflight checklist completed.

Related errors

• Claude Code API 400 invalid beta header
• Claude Code version rollback guide
• Anthropic API beta header compatibility

FAQ

What should I check first?

Start with the exact API error 400: The provider claude-4.5-opus does not support the advanced-tool-use-2025-11-20 beta header text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Claude Code workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without API error 400: The provider claude-4.5-opus does not support the advanced-tool-use-2025-11-20 beta header.