# tinker_cookbook.exceptions.BenchmarkNotFoundError

## _class_ [**tinker_cookbook.exceptions.BenchmarkNotFoundError**](https://github.com/thinking-machines-lab/tinker-cookbook/blob/main/tinker_cookbook/exceptions.py#L268)( _[EvalError](https://tinker-docs.thinkingmachines.ai/cookbook/api-reference/exceptions/evalerror/), KeyError_)

The requested benchmark is not in the registry.

Raised when `run_benchmark("unknown_name", ...)` is called and
the name cannot be resolved — neither by direct registry lookup
nor by auto-importing `tinker_cookbook.eval.benchmarks.<name>`.

Available benchmarks are listed in the error message.