I’m using https://api.tfl.gov.uk/Stoppoint/__from__/FareTo/__to__ to get data for my MTR Crossrail staff app.
It works well for almost everything I throw at it using the existing table I have of Stoppoint codes.
However, it is as fussy than the Single Fare Finder for the terminus stations in Zone 1.
I’ve found I have to map from and to like this
$arrAlternatives = [
"910GLIVST" => ["940GZZLULVT"],
"910GPADTON" => ["940GZZLUPAC", "940GZZLUPAH"],
"910GVICTRIC" => ["940GZZLUVIC"],
"910GLNDNBDC" => ["940GZZLULNB"],
"910GWATRLMN" => ["940GZZLUWLO"],
"910GKNGX" => ["940GZZLUKSX"],
"910GEUSTON"=>["940GZZLUEUS"],
];
Given that the API returns all the possible routes, it might be useful for the API to accept alternative NAPTANs.