nym/documentation/docs/src/sdk/rust/examples/custom-network.md

Importing and using a custom network topology

If you want to send traffic through a sub-set of nodes (for instance, ones you control, or a small test setup) when developing, debugging, or performing research, you will need to import these nodes as a custom network topology, instead of grabbing it from the Mainnet Nym-API (examples/custom_topology_provider.rs).

There are two ways to do this:

Import a custom Nym API endpoint

If you are also running a Validator and Nym API for your network, you can specify that endpoint as such and interact with it as clients usually do (under the hood):

{{#include ../../../../../../sdk/rust/nym-sdk/examples/custom_topology_provider.rs}}

Import a specific topology manually

If you aren't running a Validator and Nym API, and just want to import a specific sub-set of mix nodes, you can simply overwrite the grabbed topology manually:

{{#include ../../../../../../sdk/rust/nym-sdk/examples/manually_overwrite_topology.rs}}