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The API key authentication policy verifies Unkey API keys before requests reach your app. On success, it produces a Principal containing the key’s identity, metadata, roles, and permissions.

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Configure API key authentication

To enable API key authentication for your deployment:
  1. Open your project’s policy settings in the dashboard.
  2. Click Add policy.
  3. Select Key Auth as the policy type.
  4. Choose one or more keyspaces to verify against.
  5. Optionally configure match conditions, a custom key location, a permission query, or a credit cost.
  6. Select which environments (production, preview, or both) to enable the policy for.
  7. Save the policy.
Once configured, the gateway verifies every incoming request that matches the policy’s conditions against the selected keyspaces. Requests without a valid API key receive a 401 response and never reach your app.

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How verification works

The gateway extracts the API key from the Authorization header (as a Bearer token) and verifies it against your configured keyspaces. The following checks run in order:
  1. Existence. The key must belong to one of the configured keyspaces.
  2. Status. The key must not be disabled or revoked.
  3. Expiration. The key must not have passed its expiration timestamp.
  4. Credits. If remaining credits are configured, the key must have enough to cover the request’s credit cost. Verification deducts that cost (one credit by default). A cost of 0 skips this check.
  5. Rate limits. All rate limit configurations attached to the key are evaluated. See rate limiting for details on response headers and behavior.
  6. Permissions. If a permission query is configured, the key must satisfy it.
If all checks pass, the gateway produces a Principal and forwards the request with the X-Unkey-Principal header. See the API key source for the full list of fields your app receives, including roles, permissions, and key metadata.

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Key location

By default, the gateway extracts the API key from the Authorization header as a Bearer token. You can override this by adding a custom key location when creating or editing a policy:

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Permission query

You can enforce Unkey RBAC permissions directly in the gateway by setting a permission query on a policy. If the authenticated key lacks the required permissions, the request receives a 403 response before reaching your app. Permission queries support AND and OR operators:
  • api.read AND api.write requires both permissions
  • api.read OR api.write requires either permission

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Credit cost

By default, each verified request deducts one credit from the key’s remaining usage. Set a credit cost on a policy to charge a different amount per route:
  • Set the cost to 0 to verify the key without spending any credits. This is useful for read-only endpoints, or when you only want the gateway to confirm the key is valid before proxying to a backend that meters usage itself.
  • Set the cost higher than 1 to charge more for expensive endpoints (for example, 3 credits per request).
Keys with unlimited remaining usage are unaffected regardless of the cost. When the cost exceeds the key’s remaining credits, the request receives a 429 response.

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Error responses

Last modified on August 13, 2026