Transitous has no GTFS coverage for much of Asia, so a search between two Osaka subway stops finds nothing — the stops are not in the feed at all. Add Google as an optional backend behind an admin setting, reusing the install's existing Places key, and fall back to Transitous whenever no key resolves. Uses the Routes API rather than the legacy Directions endpoint the request named: every other Google call here already speaks the v1/X-Goog-Api-Key family, and Google closed the legacy endpoint to Cloud projects created after March 2025. Google returns walking as turn-by-turn navigation steps where MOTIS returns one leg per walking segment, so consecutive walk steps are coalesced into a single leg — otherwise a finely-sliced walk pushed a real journey past the 20-leg cap and the whole itinerary was dropped. Both responses now name the backend that answered. The fallback is silent by design, which left an empty result ambiguous between "no data here" and "the provider you picked never ran", and the admin panel warns when Google is selected but no key resolves — or when only the admin's own key is set, which serves them and nobody else. Cost shaped the implementation, since Google bills where Transitous does not: both field masks are cut to the cheapest SKU tier that still answers the question, cache TTLs are longer than the Transitous path's, and route alternatives ride along inside the already-billed request. Addresses #1699
@trek/shared
Single source of truth for TREK's API contracts, expressed as Zod schemas and consumed by both the server (request validation + inferred DTO types) and the client (typed requests/responses).
This package is part of the incremental NestJS + React 19 migration (see the "Brownfield Rewrite" board). It is intentionally dormant until modules start importing it — adding it changes nothing for users.
Rules
- One folder per domain:
src/<domain>/<domain>.schema.ts(+.spec.ts). - Domain-agnostic building blocks live in
src/common/. - A route is only considered migrated once its contract lives here.
- Schemas are the source of truth; server DTOs and client types are inferred from them
(
z.infer<typeof schema>), never hand-duplicated.
Consumption (dev)
Both apps resolve @trek/shared to this package's TypeScript source:
- Server (
tsx): viapathsinserver/tsconfig.json. - Client (
vite): viaresolve.aliasinclient/vite.config.ts(+pathsfor the type-checker).
Production packaging (Docker / workspace wiring) is introduced in card F2, when the server first depends on this package at runtime. Until then prod builds are untouched.
Not yet here
The canonical error envelope is finalised in card F5 (it must match TREK's current Express error responses byte-for-byte), so it is deliberately not invented in F1.