A 401 between the client and the relay

A 401 response looks simple: the request did not arrive with authentication that the responding component accepted. Through a relay, however, that component is not always obvious. The rejection may come from the relay’s entrance, an upstream service, or an intermediary. The useful comparison is not between model quality or providers, but between what each piece of evidence actually establishes.

Vana API provides one endpoint at https://api.vanaapi.com, with OpenAI-compatible requests alongside Anthropic Messages and Gemini native protocols. That flexibility makes it important to inspect the request actually sent, rather than assume that selecting a model also selected the correct authentication format.

§ The status code beside the response body

The status code: HTTP 401 conventionally indicates missing or unacceptable authentication. It does not, by itself, identify which credential failed or which service rejected it.

The response body: An error message may distinguish a missing key from an invalid credential, or suggest that an upstream authentication step failed. Treat that wording as evidence, not a complete trace. Relays can translate upstream errors into a common format, and a familiar error structure does not prove its origin.

Read the status, body, and response headers together. Preserve any request identifier provided. If there is a WWW-Authenticate header, inspect it too; its absence does not settle where the failure occurred.

§ The relay credential beside the upstream credential

The client-facing credential: Your application normally authenticates to the relay using a key issued for that relay. A key issued directly by a model provider should not be assumed interchangeable with a Vana API key.

The upstream credential: The relay’s connection to a provider is a separate authentication boundary. If the response explicitly points to upstream authentication, replacing your application key repeatedly may not address the problem. Keep the request identifier and ask support to investigate the relevant boundary.

This distinction also limits the diagnosis. A 401 alone is not evidence that your account has insufficient balance, that a model is unavailable, or that the relay’s upstream credentials have expired. Those conclusions need additional information.

§ The configured request beside the transmitted request

The configuration: A terminal may show the expected environment variable, and an SDK may appear to use the intended base URL. That confirms only part of the path.

The transmitted request: A running process can retain an older environment. A project setting can override a global setting. A proxy can remove an authentication header. Check the effective hostname, request path, protocol, and presence of the expected credential without printing the credential itself.

For an OpenAI-compatible request, bearer authentication is the usual pattern. Anthropic Messages and Gemini native requests use different conventions. Follow the relay’s documented requirements for the selected protocol rather than copying headers between clients. Also distinguish the service endpoint from any API prefix your SDK expects in its base URL.

§ A minimal request beside the original client

The minimal request: Send one small, non-streaming request using a documented example, a known-supported model, and the same relay account. Keep the endpoint and protocol explicit. This reduces the number of moving parts.

The original client: Claude Code, Codex, Gemini CLI, or an OpenAI SDK may add configuration layers. If the minimal request succeeds while the client fails, compare their effective settings before changing the account key. If both fail, you have narrowed the investigation, but you have not yet proved the cause.

Change one variable at a time. Repeatedly retrying an unchanged 401 usually adds noise rather than evidence.

§ A useful report beside a credential leak

Useful evidence: Record the timestamp with timezone, HTTP method, hostname and path, selected protocol, model name, status code, sanitized error body, and request identifier. State whether the minimal request behaved differently.

Unnecessary exposure: Do not share authorization headers, API keys, full environment dumps, or sensitive prompts. Redact before sending logs; rotate any credential that was exposed.

If you are setting up a first test, create a Vana API account and use its issued key with a documented request. The goal is a small, reproducible comparison: what the client intended to send, what reached the relay, and what the response can actually tell you.