Making a system without any DI container might be tricky. There are no deep guidelines around except to arrange the stuff to interfaces and make DI around them.

Just to observe the state

• the official docs say packages shall not export any classes without interfaces (which is good by the way)
• there is an example of a DI container built upon the tokens (e.g. Angular or Nest)

https://github.com/VallanDeMorty/artanis/blob/d021ac0cd2c02f0f22ab33000e1b1828cae18499/Interface/Collections/CollectionCommands.fs#L28-L43

GIVEN a collection with Assets and criteria to filter Assets whos are bigger than X size by width and Y by height
WHEN a User use command to fetch the Collection Assets
THEN the command load Assets which has a bigger size according to the criteria

GIVEN a collection with Assets and criteria to filter Assets whos are lesser than X size by width and Y by height
WHEN a User use command to fetch the Collection Assets
THEN the command load Assets which has a bigger size according to the criteria

Current GCD implementation doesn't cover the case when b > a which cause None result

let rec gcd =
        function
        | a, b when a = b -> Some a
        | a, b when a > b -> gcd (a - b, b)
        | _ -> None

Artstation API is private means dynamic which causes plenty of errors while parsing responses. Better to design only things you need instead of doing them humble. You can keep the detail as the documentation to prevent researching every time around.

https://github.com/VallanDeMorty/artanis/blob/1d66fc70261d77fee5c619fa88d8b7d169959957/Artstation/Projects/ProjectApi.fs#L11-L80