| # Caveats | |
| ## Delayed evaluation of annotation | |
| Hamilton works with [PEP-563](https://peps.python.org/pep-0563/), postponed evaluation of annotations. | |
| That said, it *does* force evaluation of type-hints when building the function graph. So, if you're using | |
| particularly complex/slow to load python types and expecting delay, know that they will have to be evaluted | |
| when the driver is instantiated and modules are passed, so Hamilton can inspect the types and build the | |
| function graph. |