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

# L2GERSync

> How L2GERSync indexes Global Exit Root updates on the L2 side and provides fast local GER state access for claim verification and Bridge Service APIs

## What L2GERSync Does

L2GERSync manages Global Exit Root synchronization on the L2 side. When AggOracle injects a new GER into the L2 Global Exit Root Manager contract, L2GERSync captures the resulting event and stores the GER data in a local index.

This local index provides fast access to current and historical GER state for several operations:

1. **Claim verification**: Bridge claims must be verified against the current GER
2. **Proof generation**: Merkle proofs require accurate GER state
3. **API responses**: Bridge Service APIs need fast GER data access
4. **Historical queries**: Applications may need access to historical GER transitions

Without L2GERSync, each of these operations would require onchain queries or external service calls, adding latency and external dependencies.

## Architecture

## How L2GERSync Works

### GER Synchronization Workflow

L2GERSync automatically detects your contract's capabilities at startup and configures itself for compatibility with the deployed version of the L2 GER Manager contract.