LiteLLM / LiteLLM

LiteLLM Leaks Full SHA-256 Token Hash in 429 Rate Limit Error Messages

Fix LiteLLM rate limit error exposing API key hash in response body Includes evidence for LiteLLM troubleshooting demand.

Source-backed Last updated May 14, 2026 1 source Needs local verification

Category: LiteLLM
Error signature: Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit
Quick fix: Reduce request pressure, check quota or plan limits, and retry with backoff instead of immediate repeated requests.
Updated: May 14, 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

Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit is a LiteLLM failure pattern reported for developers trying to fix litellm rate limit error exposing api key hash in response body. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

LiteLLM parallel_request_limiter_v3.py line ~1261 includes full token hash in 429 response detail. When descriptor_key is 'api_key', descriptor_value is the SHA-256 hash from /key/generate. Visible to any HTTP client hitting rate limit. redact_user_api_key_info doesn't cover this path.

Common causes

When parallel request limiter returns 429, the error body includes the full 64-character SHA-256 hash of the virtual key. redact_user_api_key_info setting doesn't affect this code path. Security concern for proxy deployments.
LiteLLM parallel_request_limiter_v3.py line ~1261 includes full token hash in 429 response detail. When descriptor_key is 'api_key', descriptor_value is the SHA-256 hash from /key/generate. Visible to any HTTP client hitting rate limit. redact_user_api_key_info doesn't cover this path.

Quick fixes

Confirm the exact error signature matches Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit.
Check the LiteLLM account, local tool state, and provider configuration involved in the failing workflow.
Reduce request pressure, check quota or plan limits, and retry with backoff instead of immediate repeated requests.

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 Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit 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 Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit mean in LiteLLM?

Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit indicates the workflow described by "LiteLLM Leaks Full SHA-256 Token Hash in 429 Rate Limit Error Messages" failed in a LiteLLM context. Start by confirming the exact signature and the component that emitted it.

What should I check first for Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit?

Check whether this cause matches your environment: When parallel request limiter returns 429, the error body includes the full 64-character SHA-256 hash of the virtual key. redact_user_api_key_info setting doesn't affect this code path. Security concern for proxy deployments.

Is the Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit guidance source-backed?

The "LiteLLM Leaks Full SHA-256 Token Hash in 429 Rate Limit Error Messages" 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 Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit?

For "LiteLLM Leaks Full SHA-256 Token Hash in 429 Rate Limit Error Messages", avoid applying "Reduce request pressure, check quota or plan limits, and retry with backoff instead of immediate repeated requests." 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 Rate limit exceeded for api_key: <sha256_hash>. Limit type: parallel_request_limit?

For "LiteLLM Leaks Full SHA-256 Token Hash in 429 Rate Limit Error Messages", 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.