Swapi.fsx

// Add NuGet package FSharp.Data
#r "../packages/FSharp.Data.2.3.2/lib/net40/FSharp.Data.dll" //#r is needed in .fsx file. You can omit this line in .fs file.
open FSharp.Data

let apiUrl = "http://swapi.co/api/people/?format=json"

type People = JsonProvider<"http://swapi.co/api/people/?format=json">
type Planet = JsonProvider<"http://swapi.co/api/planets/1/"> // * planet was found by inspecting....
// assumption made, all planets have the same json structure/properties as planet #1

let luke =
    People.Load(apiUrl).Results //Results is property of first page of people in this case.
    |> Seq.tryFind (fun guy -> guy.Name.StartsWith("Luke"))

let lukePlanet = luke |> Option.map (fun guy -> guy.Homeworld) // * <--- that string

let lukeWorldInfo =
    match lukePlanet with
    | None -> "Couldn't find the guy, no info about his planet."
    | Some(planet) -> Planet.Load(planet).Name