OpenAI API / OpenAI API

AzureOpenAI with AAD bearer token returns 401 in SDK v2.34.0+ (Regression)

Fix sudden 401 authentication failure when upgrading azure-openai SDK that previously worked on older versions Includes evidence for OpenAI API troubleshooting demand.

Source-backed Last updated May 22, 2026 1 source Needs local verification

Category: OpenAI API
Error signature: AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after
Quick fix: Verify the account session, API key, provider settings, and environment where the failing tool is running.
Updated: May 22, 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 OpenAI API, 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

AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after is a OpenAI API failure pattern reported for developers trying to fix sudden 401 authentication failure when upgrading azure-openai sdk that previously worked on older versions. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue #3282 in openai/openai-python by pfijen, opened May 20 2026. Regression in SDK v2.34.0 breaking Azure AD OAuth auth flow. Affects enterprise users who rely on AAD token-based auth — high commercial value due to billing/production impact.

Common causes

GitHub issue #3282 in openai/openai-python by pfijen, opened May 20 2026. Regression in SDK v2.34.0 breaking Azure AD OAuth auth flow. Affects enterprise users who rely on AAD token-based auth — high commercial value due to billing/production impact.

Quick fixes

Confirm the exact error signature matches AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after.
Check the OpenAI API 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 AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after exactly before applying the quick fix.
Compare the failing environment with OpenAI API 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 AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after mean in OpenAI API?

AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after indicates the workflow described by "AzureOpenAI with AAD bearer token returns 401 in SDK v2.34.0+ (Regression)" failed in a OpenAI API context. Start by confirming the exact signature and the component that emitted it.

What should I check first for AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after?

Check whether this cause matches your environment: GitHub issue #3282 in openai/openai-python by pfijen, opened May 20 2026. Regression in SDK v2.34.0 breaking Azure AD OAuth auth flow. Affects enterprise users who rely on AAD token-based auth — high commercial value due to billing/production impact.

Is the AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after guidance source-backed?

The "AzureOpenAI with AAD bearer token returns 401 in SDK v2.34.0+ (Regression)" 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 AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after?

For "AzureOpenAI with AAD bearer token returns 401 in SDK v2.34.0+ (Regression)", 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 AAD bearer token passed via api_key works in 2.33.0 but returns 401 in 2.34.0 and after?

For "AzureOpenAI with AAD bearer token returns 401 in SDK v2.34.0+ (Regression)", collect the failing OpenAI API command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.