I love the tool but one thing which I simply don't understand is why can you specify the output in the config but not the input?

I try to establish an API-first approach in our projects. For this purpose, I want the code generation to be as simple as possible.
I created a config.yaml for this:

# yaml-language-server: $schema=https://raw.githubusercontent.com/oapi-codegen/oapi-codegen/HEAD/configuration-schema.json
package: api
output: ../../../services/maconomy/maconomy_client.gen.go
generate:
  models: true
  client: true
  embedded-spec: true

As there is an output option, it seems to me just logical that there is also an option to specify the input (i.e the path to the openapi spec) but this seems to be not the case?

So instead of running:

oapi-codegen -config cfg-maconomy-client.yaml 

I need to run:

oapi-codegen -config cfg-maconomy-client.yaml ../../specs/maconomy/api.yaml

And when I want to run the generation from within a parent directory, I have to update both the path to the config.yaml and to the open-api.yaml.

It's just an inconvenience and not a blocker but it surprises me and I couldn't find anything about this in the docu. Maybe I am missing something and there is a good reason for this decision? I would like to understand this. Any help is much appreciated.