# GOF check_design: structural checks after ECO

The check_design API looks for unresolved modules, floating connections, and multiple drivers.

## Scope

By default it checks all instances and wires. Use the ECO option to restrict the check to changed instances and wires:

```perl
check_design('-eco');
```

## Review status

AI summary by Codex of the public API reference; not executed in this pilot.

## Source

https://nandigits.co/gof_manual.php — version 11.10, Appendix A, check_design.