Same treatment as AlbumApplicationResponse, but Track is the cleaner
case: OwnerUserId (local-only) and ExternalId (external-only) are
both genuinely exclusive to one side, so the base carries neither and
is abstract — every real value is one of the two derived types.
TrackApplicationResponse (abstract, shared fields + FromEntity dispatch)
LocalTrackApplicationResponse (+ OwnerUserId)
ExternalTrackApplicationResponse (+ ExternalId)
Hit a real gotcha along the way: the response already had an explicit
Source property, which collides with the "source" discriminator STJ's
polymorphism support injects ("contains property 'source' that
conflicts with an existing metadata property name" — only surfaced at
runtime in the Api integration tests, not at build time). Fixed by
dropping the now-redundant explicit Source field entirely; the
discriminator already serializes the identical "Local"/"YouTube"
value under the same name, so the wire contract is unchanged. Updated
the two call sites that read .Source directly (TrackSearchItemResponse
and a playlist track filter that needed flatMap instead of
filter().map() to keep the narrowing across the chain).
web-player
Musify's web client: SvelteKit 2 (adapter-node), Svelte 5 runes, Tailwind 4,
TypeScript. Authentication is server-side OIDC against Zitadel (openid-client
and jose) with an encrypted session cookie; the backend is called from load
functions and form actions through a typed openapi-fetch client.
Development
npm install
npm run dev # :5173
Configuration lives in .env (template in .env.example). Bring the
infrastructure stack up first (see ../deploy/README.md)
and copy the WEB_CLIENT_ID / WEB_CLIENT_SECRET it writes to deploy/.env
into this .env once, then run the dev server.
npm run check # svelte-check — must be clean before closing a change
npm run lint # prettier --check . && eslint .
npm run format # prettier --write .
npm run build # production build into build/
npm run gen:api # regenerate src/lib/api/schema.d.ts from the running API
Production
Built and run as a container by the production stack — see
../deploy/README.md. There the same variables come from
deploy/.env.prod through compose instead of from .env.
Conventions and the design system are documented in CLAUDE.md and
in the musify-web skill.