---
title: "@playstack/nest-event-store"
description: "Thin NestJS dependency-injection and worker wiring for the Playstack event store."
tags: ["package","events","event-sourcing","nestjs","pro"]
---

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> **Pro.** Covered by the Playstack Pro License. Registry access is required; check preview availability before installing. See [package access](/docs/packages#access-policy).

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`@playstack/nest-event-store` registers native Castore stores and idempotent projection adapters, then schedules persisted-log projection work through application-owned BullMQ infrastructure.

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## Install

After confirming [preview access](/docs/packages#access-policy), install the package at your application's shared Playstack version:

```sh
npm install --save-exact @playstack/nest-event-store@0.1.0-beta.1
```

Check the peer requirements below before choosing a runtime or provider.

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## Compose root and features

```ts
PlaystackEventStoreModule.forRoot({
  app: 'catalog-api',
  environment: 'production',
  source,
  checkpoints,
  batchSize: 100,
  schedulerEveryMs: 1_000,
})

PlaystackEventStoreModule.forFeature({
  stores: [orders],
  projections: [
    { id: 'order-search', adapter: orderSearch, reset: () => search.clear() },
  ],
  commandHandlers: [SubmitOrderHandler],
})
```

## Root configuration

| Property | Required | Purpose |
| --- | --- | --- |
| `app`, `environment` | Yes | Qualify the BullMQ prefix consistently with `@playstack/queues`. |
| `source` | Yes | Reads projection events from the persisted log. |
| `checkpoints` | Yes | Stores per-projection positions. |
| `batchSize` | No | Events read per job. |
| `schedulerEveryMs` | No | Projection scheduling cadence. |
| `bullRoot` | No | BullMQ root options when the application has not already configured them. |
| `enableCqrs` | No | Enables optional Nest CQRS command-handler registration. |

`forRootAsync` keeps `app`, `environment`, imports, injection, and `enableCqrs` at module construction time; its factory returns only source, checkpoints, and runtime tuning.

## Feature and replay properties

Each projection definition has a stable `id`, idempotent adapter, optional event-store filter, and optional `reset` callback that clears derived state. `ProjectionReplayService.replay(id)` calls reset, clears the checkpoint, and rebuilds from the first persisted event.

Projection jobs always read the authoritative persisted log; they never depend on Nest’s in-process `EventBus`. Delivery remains at-least-once.

## Boundary

This module is non-global thin wiring. Aggregate behavior, storage, upcasters, projection logic, BullMQ root lifecycle, and queue processors remain in core packages or application code.

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## API entry points and requirements

Reference snapshot: `@playstack/nest-event-store@0.1.0-beta.1`. Import only the entry point your runtime needs. Paths below are relative to the installed package; use **Go to Definition** in your editor to inspect exact parameters, return types and overloads. Do not import the declaration-file paths directly.

| Public entry point | Declaration file |
| --- | --- |
| `@playstack/nest-event-store` | `./dist/index.d.ts` |
| `@playstack/nest-event-store/bullmq` | `./dist/bullmq.d.ts` |
| `@playstack/nest-event-store/cqrs` | `./dist/cqrs.d.ts` |
| `@playstack/nest-event-store/package.json` | No TypeScript declaration (asset or metadata export). |

Node.js engine requirement: `>=20`. This is not a claim that every entry point works in browsers or Workers.

### Peer dependencies

Keep existing framework versions that satisfy these ranges. Install optional peers only when using the corresponding adapter. The package manager resolves ordinary dependencies separately.

| Peer | Compatible range | When needed |
| --- | --- | --- |
| `@nestjs/bullmq` | `^10.0.0 \|\| ^11.0.0` | Optional; only for the entry points that use it. |
| `@nestjs/common` | `^10.0.0 \|\| ^11.0.0` | Required by the package. |
| `@nestjs/core` | `^10.0.0 \|\| ^11.0.0` | Required by the package. |
| `@nestjs/cqrs` | `^10.0.0 \|\| ^11.0.0` | Optional; only for the entry points that use it. |
| `@playstack/event-store` | `0.1.0-beta.1` | Required by the package. |
| `bullmq` | `>=5.16.0 <7` | Optional; only for the entry points that use it. |
| `reflect-metadata` | `^0.1.13 \|\| ^0.2.0` | Required by the package. |
| `rxjs` | `^7.0.0` | Required by the package. |

For a complete first program, start with [Getting started](/docs/getting-started). For API lookup and partial-example conventions, see [Reading the reference](/docs/packages#reading-the-reference). Provider failures, lifecycle requirements and application responsibilities remain described in the guide above; types alone do not establish production safety.

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