cf17b0b6c6
The VK-only scaffolding had a shape problem worth fixing before anything was built on it: completeCallback(code, codeVerifier) took the PKCE verifier from the client, which forces the browser to generate and hold it. We are a confidential client - a browser-held verifier buys nothing and adds a place to steal it from. Replaces the four vk-id-* files with a provider-agnostic surface: getAuthorizeUrl(provider, returnTo?) listIdentities() unlink(provider) completeCallback is gone entirely. The backend mints and stores state and code_verifier single-use for 10 minutes, handles the provider's callback itself, issues the session cookie and redirects. VK and Yandex differ only in a path segment, because everything that actually differs between them - PKCE handling, VK's device_id, Yandex's Basic-auth exchange - lives backend-side. vk-id-login becomes social-login-button with a provider input; adding Yandex to the UI is an input value, not new code. Adds yandex_id to ExternalIdentityProvider, plus optional email/phone/displayName since VK frequently returns no email. social-identity-gateway.spec.ts (5 tests) asserts the requests carry no code_verifier and no client_secret, so reintroducing a browser-held verifier fails the build rather than passing review. PHASE-8 §2 rewritten to match: the four endpoints, backend-owned state and verifier, UNIQUE (provider, providerUserId) with conflict routed to controlled resolution rather than a silent rebind, per-tenant OAuth app config under the Track S §4.2 envelope, and both providers' full endpoint sets. Two things recorded there because they are expensive to discover later: VK's callback returns device_id alongside code and the token exchange fails without it, and both providers validate redirect_uri against an exact registered list - which a multi-tenant platform cannot satisfy without a central identity host (FH-0.1, still undecided). 256 tests pass. Build green, boundaries and cycles green. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Backend Contracts Index — Product Plan v3.1
New here? Start with BACKEND-HANDOFF.md — reading order, current infrastructure state, auth surface, and what a working dev environment still needs.
Implementing tenant routing/nginx? TENANT-API-DOMAIN-HANDOFF.md is the final host normalization, CORS, TLS, reverse-proxy, CI-secret, and acceptance contract.
Want every endpoint in one place? FRONTEND-API-SURFACE-COMPLETE.md — the final handoff doc. Generated directly from source, all 90 endpoints the frontend currently calls plus 3 response-shape additions on existing endpoints, marked Specified / Inferred / Undocumented against the contracts below. Use it to see gaps across all contracts at once; use the individual Phase/Track docs for full entity shapes and invariants.
This directory is the complete set of wire contracts for building the backend behind Product Plan v3.1. Each doc specifies entities, endpoints, and invariants only — never DB schema or service boundaries, which stay backend's own call.
Read order matches build order. Every doc after Phase 1 depends on the ones before it (noted at the top of each). All Sprint 0.1 decisions referenced throughout were answered 2026-08-17 — see PRODUCT-PLAN-v3.1-DELIVERY-PLAN.md Sprint 0.1 for the full record.
Launch-gate phases (P0 — required before production)
| Doc | Covers | Status |
|---|---|---|
| PHASE-1-MONEY-FX-PAYMENTS-CONTRACT.md | Money model, FX quote, price snapshot, server-authoritative checkout amount, payment state machine | Ready |
| PHASE-2-ORDERS-NOTIFICATIONS-CONTRACT.md | Canonical Order/OrderLine/Fulfillment (unified multi-seller), event bus, Notification Center | Ready |
| PHASE-3-CATALOG-OFFER-FULFILLMENT-CONTRACT.md | Product/Offer split, inventory/reservations, publish-time executability | Ready |
| PHASE-4-CONNECTOR-FRAMEWORK-CONTRACT.md | Generic external-order connector framework (no fixed marketplace list) | Ready |
Post-launch-gate phases (P1/P2)
| Doc | Covers | Status |
|---|---|---|
| PHASE-5-SELLER-PORTAL-CONTRACT.md | Seller org/user/membership, seller-scoped order/fulfillment views | Ready |
| PHASE-6-CART-CHECKOUT-CONTRACT.md | Server-owned cart, checkout session | Ready |
| PHASE-7-PAYMENTS-RECONCILIATION-CONTRACT.md | Refunds, reconciliation, settlements | Ready |
| PHASE-8-IDENTITY-MESSAGING-CONTRACT.md | Customer identity, VK ID (built first), OTP, MAX/Telegram bots, Notification Orchestrator | Ready |
| PHASE-9-TENANT-REGISTRY-DOMAINS-CONTRACT.md | Marketplace registry, Hostinger DNS automation, publish/revision model | Ready |
| PHASE-10-CONTENT-MODULES-CONTRACT.md | Gorbushka-class mall/directory content entities | Ready, lowest priority |
Cross-cutting tracks
| Doc | Covers | Status |
|---|---|---|
| TRACK-A-ANALYTICS-CONTRACT.md | Event pipeline, funnel, operational/quality metrics, synthetic-traffic separation | Ready — start alongside Phase 1, longest lead time |
| TRACK-S-SECURITY-RBAC-CONTRACT.md | 17 roles/3 scopes, enforcement, audit log, secrets, rate limiting, step-up auth | Ready — gates the launch |
| PARTNER-PROVISIONING-API-CONTRACT.md | Inbound partner API: merchant hierarchy provisioning, idempotency, public-key credentials, payment routing context | Draft — mapping decided, needs Company/Project entities |
What is deliberately not in this directory
- API namespace migration — Sprint 0.1 decision: new endpoints only use
/api/v2/...etc; legacy endpoints (/cart,/orders,/items) are not being migrated as part of this contract set. SeeBACKEND-API-REFERENCE.mdfor the current live surface. - Per-connector adapters (Ozon, Wildberries, etc.) — Sprint 0.1 decision: no fixed list. Phase 4 §8 is the onboarding runbook; each partner's adapter is written when that partner is actually onboarded.
- Additional payment providers (wallets, BNPL) — open business decision, not yet made. Phase 7 §4.
One open item across all of these
Backend ownership — answered 2026-08-18. A separate backend developer implements against these contracts. This repository's team owns the frontend and owns this contract set — the docs here are the handoff surface between the two, so a change to any contract is a change both sides must see. Keep them current; they are not a one-time deliverable.