Handling API Relay 401 Errors Step by Step

What a 401 response means at an API relay

A 401 response usually means the service handling your request could not accept its authentication credentials. The key might be missing, invalid, revoked, or sent in the wrong format. With a relay, there can also be multiple authentication boundaries: your client authenticates to the relay, and the relay communicates with an upstream provider.

The goal is to identify which boundary rejected the request, then correct the configuration. Repeatedly sending the same request rarely fixes a persistent authentication problem.

Identify which service returned the 401

1. Read the response body before changing anything. Note the error message, request ID if present, timestamp, and destination hostname. These details help distinguish a relay authentication failure from an upstream error forwarded by the relay. A status code alone does not establish which service rejected the credentials.

Keep diagnostic information private. Do not paste authorization headers, full API keys, or sensitive request content into public issues. If a key has already been exposed, revoke it and replace it rather than merely deleting the visible copy.

Check the relay address and client base URL

2. Confirm that your client is sending requests to the intended relay rather than its default provider endpoint. Relay365 is a pay-as-you-go relay desk for multiple model families. Its API base is https://api.api365relay.com; OpenAI clients use https://api.api365relay.com/v1.

Check how your client constructs endpoint paths. Setting a base URL that already contains a resource path can produce an unintended address. Also check for duplicated /v1 segments. Path mistakes often produce other status codes, but verifying the destination prevents you from troubleshooting authentication against the wrong service.

Verify the key belongs to the destination service

3. Use credentials issued for the service receiving the request. A direct provider key should not be assumed to work at a relay, and a relay key should not be sent to a provider's endpoint. Confirm that the selected key remains active in your account.

When copying credentials, check for surrounding quotation marks, trailing spaces, or accidental line breaks. If the dashboard shows the key was revoked, create a replacement through the supported account controls and update your application's secret storage.

Check how your client sends authentication

4. Follow the relay's documented authentication format. OpenAI-compatible clients commonly send the API key through an Authorization header using the Bearer scheme. When an SDK manages that header, configure its API key setting rather than adding a second, potentially conflicting header yourself.

Relay365 works with Claude Code, Codex, Gemini CLI, and OpenAI SDKs, but their configuration mechanisms differ. Check the instructions for your specific client. An environment variable that one tool recognizes may be ignored by another.

Confirm the running process received your changes

5. Restart the relevant application after updating credentials or environment settings. A terminal, editor extension, container, background service, and deployment can each have different environments. Updating your local shell does not automatically update an already-running process or a deployed application.

Verify that the expected credential setting is present without printing its value. Also inspect configuration precedence: an explicit client setting or project configuration may override an environment variable you just corrected.

Test one minimal request and inspect the result

6. Send one small request through the same client configuration. Use a model identifier documented by the relay and available to your account. If choosing Gemini 2.5 Flash, for example, verify its exact API identifier rather than assuming its display name is accepted.

A successful minimal request narrows the issue to differences in the original application. If the response changes to a quota, permission, or model error, investigate that new message separately. Do not assume every rejection is another form of 401, and avoid automatic retries while authentication remains invalid.

Escalate unresolved authentication errors safely

7. If the 401 persists, contact support with a sanitized error message, timestamp, request ID, client version, and configured base URL. Never include the complete key. Explain which checks you completed so support can focus on account status or relay-side authentication.

If a pay-as-you-go relay fits your workflow, create a Relay365 account and configure one client first. Keep credentials in appropriate secret storage, separate development from production settings, and retain a minimal request for future troubleshooting.