> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pcm.game/llms.txt
> Use this file to discover all available pages before exploring further.

# The Dual-Database Pipeline

> Cloud Run orchestration between ephemeral NoSQL and persistent ACID ledgers.

# The Dual-Database Pipeline

PCMTG operates on a fully serverless, event-driven topology within the Google Cloud Platform (GCP)\[cite: 438]. Operating a high-speed NoSQL database alongside a rigid relational ledger introduces the classic distributed systems challenge: Eventual Consistency and State Synchronization\[cite: 499].

## 1. Live Game State (Firestore - NoSQL)

Firestore is optimized for massive parallel reads and real-time websocket pushes, used strictly for "in-flight" data like the active Poker Tables\[cite: 507].

<Warning>
  **The Secret Vector Exploit:** Firestore client SDKs fetch entire documents\[cite: 514]. To prevent players from reverse-engineering the math via Chrome DevTools, the `secret_vector` is placed in an air-gapped private subcollection (`secure_data/solution`) that is locked down by Firestore Security Rules and only accessible via the Cloud Run Admin SDK\[cite: 516, 517, 520, 530].
</Warning>

## 2. Core Economy (Neon Postgres - SQL)

The persistent economy requires ACID compliance, ensuring a player cannot spend the same currency twice\[cite: 470, 471]. This database handles the `CardMasterRegistry` and the `DynamicExchangeLedger`\[cite: 471].

## 3. The Resolution Bridge

The Next.js client never writes directly to Cloud SQL\[cite: 502]. Instead, Cloud Scheduler triggers the Cloud Run `GameLogicManager`, which reads the final Firestore state, calculates the math, opens a secure SQL transaction, and only then updates the Firestore table status\[cite: 504, 505].