---
id: ADR-0001
title: Extract auth and payment into shared @marketplaces packages
status: active
date: 2026-08-17
supersedes: []
tags: [architecture, auth, payment, monorepo]
---

# ADR-0001: Extract auth and payment into shared @marketplaces packages

## Context

`marketplaces` currently owns auth end-to-end: customer auth (`core/auth` — VK ID, OTP, session, facade), admin auth (`core/admin-auth` — ed25519-verified admin sessions, permission guards, interceptor), and a legacy `services/auth.service.ts`. Payment/finance logic (`core/finance`, `core/pricing`) is server-owned per [Phase 1](../../backend/PHASE-1-MONEY-FX-PAYMENTS-CONTRACT.md) and [Phase 7](../../backend/PHASE-7-PAYMENTS-RECONCILIATION-CONTRACT.md) contracts — the frontend piece is thin (gateways/tokens, no business logic).

Multiple marketplace projects beyond this repo need the same auth and payment client logic. Duplicating it per-project drifts fast (auth bugs get fixed in one place, not others) and blocks a consistent security posture across projects — directly relevant to [TRACK-S-SECURITY-RBAC-CONTRACT.md](../../backend/TRACK-S-SECURITY-RBAC-CONTRACT.md), which already treats auth/RBAC as the single most serious cross-cutting concern.

## Decision

Extract auth and payment client logic into two standalone, independently versioned npm packages:

- `@marketplaces/auth` — customer auth (VK ID/OTP/session), admin auth (ed25519 verification, permission guards, interceptors), token/session management.
- `@marketplaces/payment` — payment/finance client gateways, FX/pricing models, checkout client contracts (thin — business logic stays backend per Phase 1/7).

Each package:
1. Lives in its own git repo (handed over separately; this repo does not host it long-term).
2. Is consumed by `marketplaces` (and other projects) as an installed node_modules dependency — imported, never copy-pasted.
3. Is versioned with semver; CI on the package repo auto-bumps and publishes on push to `main`, driven by conventional commit prefixes already used in this repo (`feat:`/`fix:`/etc — semantic-release reads these directly).
4. Ships with its own test suite; `marketplaces` treats it as a black-box dependency, not source to edit in place.

Rollout order: scaffold packages and CI in this repo first (reversible, local-only) → hand over target git repo → publish → migrate `marketplaces` call sites to import from the package → delete the in-repo originals only after the app builds and passes tests against the package.

## Consequences

- `marketplaces` loses direct edit access to auth/payment source — changes go through the package's own repo/PR/release cycle. Slower iteration, but consistent behavior across all consuming projects.
- ~30 call sites in `marketplaces` (see `core/auth`, `core/admin-auth`, `services/auth.service.ts`, interceptors) need import rewiring during migration — tracked as follow-up work, not done in this ADR.
- New failure mode: package registry/CI outage blocks `marketplaces` builds if a version bump lands mid-incident. Pin exact versions, do not use floating ranges, to keep this bounded.
- [TRACK-S-SECURITY-RBAC-CONTRACT.md](../../backend/TRACK-S-SECURITY-RBAC-CONTRACT.md) §8 (admin provisioning) becomes package-owned behavior once migrated — that doc's endpoint contracts stay backend-side and unaffected, only the frontend client implementation moves.