> ## Documentation Index
> Fetch the complete documentation index at: https://nexus-core.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Nexus Core: Centralized Cache Orchestration for Minecraft

> Nexus Core is a standalone Java orchestration layer that centralizes all data operations for distributed Minecraft server networks over Redis pub/sub.

Nexus Core is a standalone Java application that acts as a centralized data orchestration layer for distributed Minecraft server networks. Instead of every Spigot server maintaining its own MongoDB connection pool and managing its own cache, all data operations are delegated to Nexus Core through a Redis pub/sub messaging layer. Think of it as a microservice built specifically for Minecraft infrastructure: Nexus Core owns all data, while your Spigot servers act as thin clients.

As of v1.7.0, all communication is **fully authenticated in both directions**: inbound packets from Spigot servers are verified, and outbound responses from Nexus Core are signed using the same `NEXUS_SIGNING_KEY`.

## Why Nexus Core?

<CardGroup cols={3}>
  <Card title="Single Connection Pool" icon="database">
    Every Spigot server used to maintain its own MongoDB connection pool. Nexus Core replaces all of them with a single, optimized pool.
  </Card>

  <Card title="Consistent Cache" icon="layer-group">
    Per-server caches go stale and diverge. Nexus Core provides a centralized Redis cache that is always consistent across every node.
  </Card>

  <Card title="Centralized Data Logic" icon="code">
    Business rules defined once in a DataAddon are shared everywhere. No more duplicating logic across every server's codebase.
  </Card>
</CardGroup>

## How It Works

<Steps>
  <Step title="Spigot servers publish signed packets to Redis">
    Each game server constructs a JSON packet with the request type, payload, and HMAC-SHA256 security fields, then publishes it to the shared Redis channel.
  </Step>

  <Step title="Nexus Core validates and routes the packet">
    Nexus Core verifies the signature, timestamp, and nonce, then looks up the matching DataAddon in its registry.
  </Step>

  <Step title="Data is served from Redis or MongoDB">
    The addon checks the Redis L2 cache first. On a cache miss, it queries MongoDB and writes the result back to cache.
  </Step>

  <Step title="Signed response published back to the source server">
    The result is serialized, signed with `NEXUS_SIGNING_KEY`, and published to the originating server's Redis channel.
  </Step>
</Steps>

## Explore the Docs

<CardGroup cols={2}>
  <Card title="Installation" icon="rocket" href="/installation">
    Build Nexus Core from source and launch the web panel.
  </Card>

  <Card title="Quickstart" icon="bolt" href="/quickstart">
    Register your first DataAddon and send a signed request in minutes.
  </Card>

  <Card title="System Architecture" icon="diagram-project" href="/concepts/architecture">
    Understand the hub-and-spoke design connecting Spigot servers, Redis, and MongoDB.
  </Card>

  <Card title="Security" icon="shield-halved" href="/concepts/security">
    Full symmetric HMAC signing on inbound and outbound packets as of v1.5.1.
  </Card>
</CardGroup>


## Related topics

- [Cache Strategy and Hierarchy in Nexus Core](/concepts/cache-strategy.md)
- [Best Practices for Building Nexus Core Addons](/addons/best-practices.md)
- [System Architecture of Nexus Core](/concepts/architecture.md)
- [DataAddon Overview: Defining Data Schemas in Nexus Core](/addons/overview.md)
- [Nexus Core Changelog](/reference/changelog.md)