OpenRouter / Cloud Platforms

OpenRouter API 401 AuthenticationError — Valid Key but Authentication Fails

Fix OpenRouter API returning 401 error even when API key is valid and has credits Includes evidence for OpenRouter troubleshooting demand.

Source-backed Last updated May 11, 2026 3 sources Needs local verification

Category: Cloud Platforms
Error signature: AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits
Quick fix: Verify the account session, API key, provider settings, and environment where the failing tool is running.
Updated: May 11, 2026
Verification status: Source-backed
Evidence: 3 public source URLs

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 OpenRouter, 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

AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits is a OpenRouter failure pattern reported for developers trying to fix openrouter api returning 401 error even when api key is valid and has credits. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Multiple GitHub issues report OpenRouter returning 401 AuthenticationError despite verified valid API keys with credits. Affected tools include hermes-agent, Cline, Aider, and Home Assistant. One user reported creating a dozen API keys without resolution, with errors randomly alternating between 401 and 'Provider returned error'.

Common causes

OpenRouter is a paid AI model aggregation service. When 401 errors occur despite valid keys, developers cannot use any downstream tools (Cline, Aider, Home Assistant, OpenClaw) that depend on OpenRouter. The intermittent nature (alternating between 401 and working) makes it especially frustrating.
Multiple GitHub issues report OpenRouter returning 401 AuthenticationError despite verified valid API keys with credits. Affected tools include hermes-agent, Cline, Aider, and Home Assistant. One user reported creating a dozen API keys without resolution, with errors randomly alternating between 401 and 'Provider returned error'.

Quick fixes

Confirm the exact error signature matches AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits.
Check the OpenRouter 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 AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits exactly before applying the quick fix.
Compare the failing environment with OpenRouter 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 AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits mean in OpenRouter?

AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits indicates the workflow described by "OpenRouter API 401 AuthenticationError — Valid Key but Authentication Fails" failed in a Cloud Platforms context. Start by confirming the exact signature and the component that emitted it.

What should I check first for AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits?

Check whether this cause matches your environment: OpenRouter is a paid AI model aggregation service. When 401 errors occur despite valid keys, developers cannot use any downstream tools (Cline, Aider, Home Assistant, OpenClaw) that depend on OpenRouter. The intermittent nature (alternating between 401 and working) makes it especially frustrating.

Is the AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits guidance source-backed?

The "OpenRouter API 401 AuthenticationError — Valid Key but Authentication Fails" page is labeled source-backed. It has 3 public source URLs from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits?

For "OpenRouter API 401 AuthenticationError — Valid Key but Authentication Fails", 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 AuthenticationError [HTTP 401] - API call failed despite valid API key and available credits?

For "OpenRouter API 401 AuthenticationError — Valid Key but Authentication Fails", collect the failing OpenRouter command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.