LiteLLM phantom BudgetExceededError — Redis spend counter leak

What this error means

BudgetExceededError (HTTP 429) is a LiteLLM failure pattern reported for developers trying to fix random litellm budgetexceedederror (429) when actual spend is near zero. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue #27639 on BerriAI/litellm (created 2026-05-11). Production deployment on EKS with 4 replicas, Redis cache enabled. Phantom BudgetExceededError cycles every 4 minutes. Root cause: reserve_budget_for_request() leaks Redis spend counters after upgrade. Directly impacts billing and user experience.

Common causes

• After upgrading to LiteLLM v1.83.10+, end users randomly receive HTTP 429 BudgetExceededError despite database spend being near $0. The Redis atomic counter spend:end_user:<id> accumulates phantom reservations that are never finalized. Requests cycle between success and failure every ~4 minutes. Critical for production proxy deployments with Kubernetes.
• GitHub issue #27639 on BerriAI/litellm (created 2026-05-11). Production deployment on EKS with 4 replicas, Redis cache enabled. Phantom BudgetExceededError cycles every 4 minutes. Root cause: reserve_budget_for_request() leaks Redis spend counters after upgrade. Directly impacts billing and user experience.

Quick fixes

1. Confirm the exact error signature matches BudgetExceededError (HTTP 429).
2. Check the LiteLLM 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/BerriAI/litellm/issues/27639

Evidence note: GitHub issue #27639 on BerriAI/litellm (created 2026-05-11). Production deployment on EKS with 4 replicas, Redis cache enabled. Phantom BudgetExceededError cycles every 4 minutes. Root cause: reserve_budget_for_request() leaks Redis spend counters after upgrade. Directly impacts billing and user experience.

Related errors

• LiteLLM Redis connection timeout
• LiteLLM proxy 500 internal server error
• LiteLLM max_end_user_budget ignored

FAQ

What should I check first?

Start with the exact BudgetExceededError (HTTP 429) text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed LiteLLM 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 BudgetExceededError (HTTP 429).