Vector API
Vector ships with a GraphQL API that allows you to interact with a running Vector instance. There's an env var to customize Vector API address:
VECTOR_API_ADDRESS=127.0.0.1:8686 # default
Monitor the Vector process from CLI

To help you visualize your Vector instance in action, there's a terminal dashboard CLI tool powered by the Vector GraphQL API. You can try it with:
vector top --url http://127.0.0.1:8686/graphql