Record the execution platform (kind vk|telegram|direct + device subtype
ios|android|web) on each session, captured at creation and carried
gateway->backend as a trusted X-Platform header, so the upcoming
store-compliance gate has an unforgeable execution context.
- backend.sessions gains nullable platform_kind/platform_subtype columns
(migration 00011, CHECK-constrained, jet regenerated); session.Platform
captures them at mint, resolve returns them, middleware exposes platform(c).
kind is derived from the establish endpoint, never a client field; the
account-merge session mint inherits the caller's platform.
- gateway derives the platform (VK subtype from the signed vk_platform via
vkauth, Telegram/direct best-effort from the client) and injects X-Platform
on every authenticated backend call through the request context.
- ui submits a best-effort device subtype on the telegram/guest/email login
requests (new FBS subtype field); VK is server-derived from the signed params.
- an unattributed session is untrusted (view-only); VK/TG self-heal on the next
cold-start re-mint, direct/email on re-login.
Signal plumbing only, no user-visible change; X-Platform is inert until the
gate consumes it.
Mirror the Telegram Mini App wrapper for VK: the SPA loads at a new /vk/
entry, authenticates from VK's signed launch parameters, and provisions a
'vk' platform identity — the minimum to run the game in VK test mode.
- Gateway verifies the launch signature in-process (internal/vkauth:
HMAC-SHA256 over the sorted vk_* params under GATEWAY_VK_APP_SECRET,
base64url) — a pure offline check, no side-service. New auth.vk op
(gated on the secret), backendclient.VKAuth, /vk/ SPA mount.
- Backend: KindVK + ProvisionVK/vkSeed, /sessions/vk handler, identity
kind widened to include 'vk' (migration 00005, expand-contract).
- UI: src/lib/vk.ts (VK Bridge, lazy-imported), bootVK + the /vk/ boot
dispatch, encodeVKLogin + authVK across transport/client/mock. VK omits
the name from the signed params, so the client reads it via
VKWebAppGetUserInfo as an unsigned display seed.
- Deploy: /vk in the edge Caddyfile, GATEWAY_VK_APP_SECRET wired through
compose + .env.example + CI (TEST_) + prod-deploy (PROD_).
- Admin console: surface the VK user id (link to the VK profile) next to
the Telegram id on the user card.
- Docs: ARCHITECTURE §12/§13, FUNCTIONAL (+ _ru), gateway README; VK
integration reference under .claude/.
Signature algorithm verified against dev.vk.com plus independent Node/Python
references and a %2C edge-case vector.
Ilia Denisov