# SDK_CREDENTIAL_CONFIGURATION_INVALID

- Surface: SDK

## Cause

`createSplitchClient` was given no credential, or both a `clientKey` and an `apiKey`.

## Fix

Pass exactly one. Use `clientKey` (the `pk_…` key material from `splitch client-key get`) for anything that evaluates, including servers. Use `apiKey` (`sk_…`, servers only) for `peekVariant`. The two unlock different methods, so the client cannot pick for you.

## Related

- [UNAUTHORIZED](https://splitch.dev/docs/error/UNAUTHORIZED)
- [INSUFFICIENT_SCOPES](https://splitch.dev/docs/error/INSUFFICIENT_SCOPES)

Source: https://splitch.dev/docs/error/SDK_CREDENTIAL_CONFIGURATION_INVALID