> For the complete documentation index, see [llms.txt](https://bootcamp.openguild.wtf/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://bootcamp.openguild.wtf/building-a-blockchain-with-polkadot-sdk/polkadot-sdk/substrate/adding-a-custom-logic-to-runtime/extensions.md).

# Extensions

- [Signed Extensions](https://bootcamp.openguild.wtf/building-a-blockchain-with-polkadot-sdk/polkadot-sdk/substrate/adding-a-custom-logic-to-runtime/extensions/signed-extensions.md)
- [Transaction Extensions](https://bootcamp.openguild.wtf/building-a-blockchain-with-polkadot-sdk/polkadot-sdk/substrate/adding-a-custom-logic-to-runtime/extensions/transaction-extensions.md)