{"about":"PKCE redirect relay: it carries an authorization code to the TV and never sees a token or a verifier.","routes":{"callback":"GET /callback?code=...&state=...","handoff":"POST /v1/handoff { code_challenge, state?, client_unique_key? }","poll":"GET /v1/handoff/{id}","sign_in":"GET /auth/{id}"},"service":"tidal-relay"}