nestarcProduction-ready NestJS modules for SaaS backends

Multi-tenancy, audit logs, feature flags, RBAC, and more — built on Prisma & PostgreSQL

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SaaS API foundation

Start with tenant isolation, consistent response envelopes, and reusable list endpoints.

Step 1 · tenancy, safe-response, pagination

Data safety

Add soft deletion and idempotency before retries, deletes, imports, or payments can corrupt state.

Step 2 · soft-delete, idempotency

Operations and auth

Add auditability, machine access, release control, and tenant-aware authorization.

Step 3 · audit-log, api-keys, feature-flag, rbac

Async and integration

Move side effects, background work, and outbound webhooks into reliable delivery flows.

Step 4 · outbox, jobs, webhook

Privacy and compliance

Model export, erase, anonymization, and retention policies before privacy requests become manual work.

Step 5 · data-subject

Package lineup

Package cards use Core for modules with mature docs and generated API reference, and Beta for published modules whose generated API reference is still being expanded.

Core · v0.13.0tenancy

PostgreSQL RLS + Prisma multi-tenancy with tenant-aware cache keys.

Core · v0.15.0safe-response

API response wrapper with Swagger integration, field selection, error catalogs, and i18n support.

Core · v0.1.0pagination

Cursor and offset pagination with filters, sorting, and Swagger helpers.

Core · v0.4.0soft-delete

Prisma soft-delete extension with cascade delete, restore, purge, and events.

Core · v0.2.0audit-log

Prisma CUD tracking with query cursors, retention, partitions, and actor metadata.

Core · v0.3.0feature-flag

DB-backed feature flags with cache adapters, Admin API, rollouts, and tenant overrides.

Beta · v0.4.0idempotency

IETF draft-07 Idempotency-Key handling with stable fingerprints, Redis/Postgres storage, and response/header replay.

Beta · v0.1.0api-keys

Tenant-scoped API keys with hashing, versioned peppers, live/test environments, and scopes.

Beta · v0.1.0rbac

Tenant-aware roles, permissions, route guards, service checks, and resource scopes.

Beta · v0.1.0outbox

Prisma-native transactional outbox with polling, retry, and event decorators.

Beta · v0.1.0jobs

Tenant-fair background jobs with in-memory scheduling, BullMQ, and context propagation.

Beta · v0.12.1webhook

Outbound webhook delivery with HMAC signing, retry, circuit breaker, and delivery logs.

Beta · v0.1.0data-subject

GDPR/CCPA export and erase workflows with entity policies, retention, and outbox fan-out.

Compare all packages Read the adoption roadmap

Why nestarc?

Every multi-tenant SaaS backend needs the same operational building blocks. Building them from scratch takes weeks and introduces subtle bugs. nestarc solves them once, correctly.

Tenant Isolation

One misconfigured query leaks customer data across tenants.

PostgreSQL RLS enforces isolation at the database level.

Audit Trail

Manually logging every write is tedious and easy to forget.

Prisma extension auto-tracks CUD with before/after diffs.

Feature Flags

External flag services add latency, cost, and a new dependency.

DB-backed flags with tenant overrides and percentage rollouts.

Soft Delete

deletedAt alone breaks unique constraints and leaks deleted records.

Prisma extension with cascade, restore, and query filtering.

Pagination

Implementing cursor + offset with filters is boilerplate-heavy.

12 filter operators, sorting, and Swagger docs out of the box.

Response Format

Inconsistent API envelopes across endpoints frustrate frontend teams.

Auto-wrapped responses with error codes, pagination, and i18n.

Idempotency

Network retries cause double charges, duplicate orders, and corrupt state.

IETF draft-07 Idempotency-Key handling with fingerprint validation and response replay.

Transactional Outbox

DB writes and event emission can get out of sync, causing lost or duplicate events.

Prisma-native outbox with polling, SKIP LOCKED, and retry with backoff.

Webhook Delivery

Reliable outbound webhooks require retry, signing, circuit breaking, and audit trails.

HMAC-signed delivery with exponential backoff, circuit breaker, and full delivery logs.

API Keys

Rolling your own key hashing, prefixing, and rotation is one bug away from a credential leak.

SHA-256 + versioned peppers, Stripe-style prefixes, and test/live environment isolation.

Access Control

Ad hoc role checks drift across controllers, services, tenants, and resource scopes.

Tenant-aware RBAC keeps roles, permissions, and guards consistent.

Data Subject Rights

GDPR/CCPA export and erase requests collide with legal retention on invoices, audits, and tax records.

Per-entity policies with delete/anonymize/retain, legal basis tracking, and outbox fan-out.

Background Jobs

One noisy tenant's backlog starves every other tenant's jobs in a plain FIFO queue.

Weighted tenant-fair scheduler with minimum share, plus BullMQ backend for production.

Without nestarc

typescript

// Scattered across 50+ services, easy to forget, hard to audit
async updateUser(id: string, dto: UpdateUserDto) {
  const before = await this.prisma.user.findUnique({ where: { id } });
  await this.prisma.$executeRaw`SELECT set_config('app.current_tenant', ${tenantId}, true)`;
  const after = await this.prisma.user.update({ where: { id, deletedAt: null }, data: dto });
  await this.auditService.log({ action: 'user.update', before, after });
  return { success: true, data: after, timestamp: new Date() };
}

With nestarc

typescript

// Tenant isolation, audit logging, soft-delete filtering, and response wrapping
// are all handled automatically by Prisma extensions and NestJS interceptors.
async updateUser(id: string, dto: UpdateUserDto) {
  return this.prisma.user.update({ where: { id }, data: dto });
}

Near-zero overhead

Core request and data modules are benchmarked. Most add less than 1ms — some make queries faster.

tenancy

-24%

RLS filters rows, fewer returned

safe-response

< 0.2ms

Response wrapping overhead

audit-log

+1ms

Per write with diff tracking

feature-flag

0.04ms

Flag evaluation (cache hit)

soft-delete

0ms

Zero overhead — actually faster

pagination

~1ms

Per page with filters & sort

idempotency

0.04ms

First-request overhead (MemoryStorage)

outbox

< 0.1ms

Emit overhead per event in transaction

webhook

< 1ms

Event persist + fan-out creation overhead

api-keys

~5µs

verify() per request (timing-safe)

data-subject

~0.5ms

erase() 1000 rows (library overhead)

jobs

~2µs

Enqueue overhead per call

Tooling

Labs · mcp-guard · v0.2.0

Static scanner for MCP servers and client configuration files. It is published under the @nestarc scope, but lives separately from the NestJS SaaS module lineup.

Explore tooling →

Build a complete multi-tenant API in 30 minutes.

Full Tutorial Quick Start (5 min)

nestarcProduction-ready NestJS modules for SaaS backends

SaaS API foundation

Data safety

Operations and auth

Async and integration

Privacy and compliance

Package lineup ​

Why nestarc? ​

Without nestarc ​

With nestarc ​

Near-zero overhead ​

Tooling ​