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An API key is application access with an owner and lifecycle, not a substitute for account eligibility, credit or a valid model route.
An OpenRouter API key lets an application call the service under your access. Create it for a defined purpose and test it independently of a complex integration. This separates authentication problems from an incorrect API address, model identifier or routing configuration. The following procedure concerns your own authorized access.
Assign an owner and purpose
Give the key a recognizable application name. Keep an internal record of its owner, environment and review date, without storing the secret value in a shared inventory. A development script and a deployed service should not depend on an unexplained credential copied from someone’s laptop.
OpenRouter documents Bearer authentication and key creation. Check the current account and key state through the supported controls. A key that exists is not proof that every model, provider or payment option is available to that account or location. Record the specific access you actually verified.
Bound the first experiment
Choose a small number of requests and a short maximum output before the first call. Apply an appropriate spending limit where supported and make any increase a deliberate decision after reviewing the result. This matters particularly when an agent can initiate calls without a person watching each one.
A new key does not automatically expand account-wide request limits. Keep rate limits, spend limits and available credits separate in the test record. A successful authentication check answers a narrower question than whether a long model request is affordable and permitted.
Keep the credential at the server boundary
Pass the secret only to the process authorized to spend API funds. A frontend bundle, notebook shared publicly or browser request can expose it. Use the project’s intended secret mechanism and check what appears in logs, exceptions and deployment configuration.
For example, document the environment variable name and retrieval procedure rather than pasting a working value into setup instructions. Ensure the actual deployed process receives the variable; a value available in an interactive terminal may be absent from a container or service. Never print the whole environment merely to debug one missing setting.
Test, rotate and retire
Make one short request to a model whose identifier and access have been checked. Save the status, response identifier and safe usage fields. Avoid including the full key or a private user document in the diagnostic record. Then verify one intentionally invalid configuration so the application handles failure clearly.
Before deployment, identify how to replace the key and update every dependent job. At the end of a pilot, revoke credentials that are no longer needed.
Official references: openrouter.ai — authentication, openrouter.ai — limits.
Related guides: OpenRouter error 401: checking credentials and the runtime, Ending a GPU pilot: finding resources that still incur charges.