> For the complete documentation index, see [llms.txt](https://cardano-course.gitbook.io/cardano-course/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cardano-course.gitbook.io/cardano-course/handbook/protocol-parameters-and-configuration-files/topology-file.md).

# Topology file

## Mainnet classic topology file:

{% embed url="<https://book.world.dev.cardano.org/environments/mainnet/topology.json>" %}