Give each operator its own Interrail booking site and reservation rules

docs/format.md

@@ -20,8 +20,10 @@ publishes it per pass in the compact snapshot format (`src/compact.ts`).
 The SNCF feed has one MAX flag for both MAX passes (they share one quota), so `max-jeune`
 and `max-senior` differ only by MAX SENIOR's own rules. Its weekday rule is applied; its
 off-peak limits (Friday afternoon and evening, Monday morning, eves of holidays) are not in
-the data, so `index.json` carries them as the pass's `note`. Interrail's `note` carries
-its residence rule, which no timetable can check.
+the data, so `index.json` carries them as the pass's `note`. For Interrail, each operator's
+entry carries its own booking site (`bookingUrl`) and reservation rules (`note`): whether a
+pass holder needs a reservation depends on the operator and the train (none on ICE within
+Germany or on Dutch domestic trains; a paid one on TGV INOUI, Frecciarossa or AVE).
 
 ## Passes
 

src/api.ts

@@ -1,5 +1,6 @@
 import { encodeCompact } from "./compact";
 import { PASSES, PASS_INFO, type PassId, type PassInfo, type Train } from "./format";
+import { INTERRAIL_BY_OPERATOR } from "./operators/interrail";
 
 /**
  * The static API: plain JSON files, so it can be hosted for free and never needs a
@@ -69,7 +70,8 @@ export function buildOperatorApi(
   for (const pass of PASSES) {
     const ok = bookableFor(trains, pass);
     if (ok.length === 0) continue;
-    passes.push({ ...PASS_INFO[pass], trainCount: ok.length });
+    const own = pass === "interrail" ? INTERRAIL_BY_OPERATOR[operator] : undefined;
+    passes.push({ ...PASS_INFO[pass], ...own, trainCount: ok.length });
     files.push({ path: `v1/${operator}/${pass}/all.json`, body: encodeCompact(ok) });
     const byOrigin = new Map<string, Train[]>();
     for (const t of ok) {

src/format.ts

@@ -65,7 +65,9 @@ export const PASS_INFO: Record<PassId, PassInfo> = {
     id: "interrail",
     name: "Interrail",
     seatKnown: false,
-    bookingUrl: "https://www.sncf-connect.com/",
-    note: "Every train here needs a paid pass-holder reservation. A Global Pass covers only one outbound and one return trip inside your country of residence.",
+    // Each operator's index entry carries its own booking site and reservation rules
+    // (src/operators/interrail.ts); these are the fallback.
+    bookingUrl: "https://www.interrail.eu/en/plan-your-trip/reservations",
+    note: "Reservation rules depend on the operator and the train. A Global Pass covers only one outbound and one return trip inside your country of residence.",
   },
 };

src/operators/interrail.ts

@@ -0,0 +1,53 @@
+import type { PassInfo } from "../format";
+
+/**
+ * Where an Interrail holder books each operator's trains, and whether they need a
+ * reservation. Reservation rules come from the operators' own pass pages and change;
+ * clients should show the note, not decide for the traveller.
+ */
+export const INTERRAIL_BY_OPERATOR: Record<string, Pick<PassInfo, "bookingUrl" | "note">> = {
+  sncf: {
+    bookingUrl: "https://www.sncf-connect.com/en-en/",
+    note: "Every TGV INOUI, Intercités, night and international train here needs a paid pass-holder reservation. A Global Pass covers only one outbound and one return trip inside your country of residence.",
+  },
+  renfe: {
+    bookingUrl: "https://www.renfe.com/es/en",
+    note: "High-speed and long-distance trains (AVE, Alvia, Euromed, Intercity) need a paid pass-holder reservation; medium-distance trains need a free one.",
+  },
+  nl: {
+    bookingUrl: "https://www.ns.nl/en",
+    note: "Domestic trains need no reservation. Eurostar needs a paid pass-holder reservation; ICE and Intercity direct don't within the Netherlands.",
+  },
+  de: {
+    bookingUrl: "https://int.bahn.de/en",
+    note: "ICE, IC and EC trains within Germany need no reservation (one is optional). Trains to France and some night trains need a paid reservation.",
+  },
+  it: {
+    bookingUrl: "https://www.trenitalia.com/en.html",
+    note: "Frecciarossa, Frecciargento, Frecciabianca, Intercity and night trains need a paid pass-holder reservation. Regionale and Regionale Veloce trains don't.",
+  },
+  ch: {
+    bookingUrl: "https://www.sbb.ch/en",
+    note: "Most trains need no reservation. TGV Lyria and some international EuroCity and night trains need a paid one.",
+  },
+  no: {
+    bookingUrl: "https://www.vy.no/en",
+    note: "Long-distance trains (F lines and SJ) need a paid seat reservation. Regional trains don't.",
+  },
+  fi: {
+    bookingUrl: "https://www.vr.fi/en",
+    note: "InterCity, Pendolino and night trains need a paid seat reservation. Regional trains don't.",
+  },
+  ie: {
+    bookingUrl: "https://www.irishrail.ie/en-ie/",
+    note: "No reservation needed.",
+  },
+  se: {
+    bookingUrl: "https://www.sj.se/en",
+    note: "SJ high-speed, long-distance and night trains need a paid pass-holder reservation. Regional trains don't.",
+  },
+  gb: {
+    bookingUrl: "https://www.nationalrail.co.uk/",
+    note: "No reservation needed, except on the Caledonian Sleeper.",
+  },
+};

tests/api.test.ts

@@ -116,6 +116,19 @@ describe("static API", () => {
     expect(decodeCompact(all)).toHaveLength(trains.length);
   });
 
+  it("sends Interrail holders to each operator's own booking site, with its reservation rules", () => {
+    const sncf = entry.passes.find((p) => p.id === "interrail");
+    expect(sncf?.bookingUrl).toContain("sncf-connect.com");
+    const interrail = { interrail: { bookable: true, seat: "unknown" as const } };
+    const train = { operator: "de", date: "2026-10-05", origin: "Köln Hbf", destination: "Berlin Hbf", depart: "08:00", arrive: "12:30", trainNo: "ICE 1", passes: interrail };
+    const de = buildOperatorApi("de", "test", [train]).entry.passes[0];
+    expect(de?.bookingUrl).toContain("bahn.de");
+    expect(de?.note).toMatch(/need no reservation/);
+    // An operator without its own entry falls back to the general rules.
+    const other = buildOperatorApi("xx", "test", [{ ...train, operator: "xx" }]).entry.passes[0];
+    expect(other?.bookingUrl).toContain("interrail.eu");
+  });
+
   it("answers a search by origin, destination and date from one origin file", () => {
     const stations = file("v1/sncf/stations.json") as { id: string; name: string }[];
     const paris = stations.find((s) => s.name === "PARIS (intramuros)");