An extension that adds support for the vector type.

Create a file with these contents, not inside of a module:

Postgrex.Types.define(<YourApp>.PostgrexTypes, [AshPostgres.Extensions.Vector] ++ Ecto.Adapters.Postgres.extensions(), [])

And then ensure that you refer to these types in your repo configuration, i.e

config :my_app, YourApp.Repo,
  types: <YourApp>.PostgrexTypes