LiteLLM / LiteLLM

LiteLLM OAuth handler overwrites anthropic-beta header dropping client beta features

Requests with newer Anthropic beta headers silently lose functionality when proxied through LiteLLM's OAuth handler; developers unaware of silent feature loss Includes evidence for LiteLLM troubleshooting demand.

Source-backed Last updated May 20, 2026 1 source Needs local verification

Category: LiteLLM
Error signature: oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching)
Quick fix: Verify the account session, API key, provider settings, and environment where the failing tool is running.
Updated: May 20, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for LiteLLM, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching) is a LiteLLM failure pattern reported for developers trying to requests with newer anthropic beta headers silently lose functionality when proxied through litellm's oauth handler; developers unaware of silent feature loss. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue #22398 on BerriAI/litellm — optionally_handle_anthropic_oauth() replaces entire anthropic-beta header, stripping client-sent beta features. Silent bug affecting paid LiteLLM proxy deployments. Distinct from general rate-limit/error issues. Category: LiteLLM (proxy-specific).

Common causes

GitHub issue #22398 on BerriAI/litellm — optionally_handle_anthropic_oauth() replaces entire anthropic-beta header, stripping client-sent beta features. Silent bug affecting paid LiteLLM proxy deployments. Distinct from general rate-limit/error issues. Category: LiteLLM (proxy-specific).

Quick fixes

Confirm the exact error signature matches oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching).
Check the LiteLLM account, local tool state, and provider configuration involved in the failing workflow.
Verify the account session, API key, provider settings, and environment where the failing tool is running.

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

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

Diagnostic flow for this page

Match oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching) exactly before applying the quick fix.
Compare the failing environment with LiteLLM versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching) mean in LiteLLM?

oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching) indicates the workflow described by "LiteLLM OAuth handler overwrites anthropic-beta header dropping client beta features" failed in a LiteLLM context. Start by confirming the exact signature and the component that emitted it.

What should I check first for oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching)?

Check whether this cause matches your environment: GitHub issue #22398 on BerriAI/litellm — optionally_handle_anthropic_oauth() replaces entire anthropic-beta header, stripping client-sent beta features. Silent bug affecting paid LiteLLM proxy deployments. Distinct from general rate-limit/error issues. Category: LiteLLM (proxy-specific).

Is the oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching) guidance source-backed?

The "LiteLLM OAuth handler overwrites anthropic-beta header dropping client beta features" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching)?

For "LiteLLM OAuth handler overwrites anthropic-beta header dropping client beta features", avoid applying "Verify the account session, API key, provider settings, and environment where the failing tool is running." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging oauth handler overwrites anthropic-beta header — only oauth-2025-04-20 retained, newer beta features dropped (e.g. prompt caching)?

For "LiteLLM OAuth handler overwrites anthropic-beta header dropping client beta features", collect the failing LiteLLM command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.