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

# Linea / Besu Integration

> High-level integration of the Credible Layer with Linea via Besu plugins

This page summarizes the Linea integration pattern at a high level. It focuses on interface boundaries
and the enforcement flow without internal implementation details.

## Integration Pattern

Linea uses a **plugin pattern** that integrates directly with the Besu node through its plugin system
and delegates assertion execution to a sidecar process.

Key characteristics:

* **Plugin-based enforcement**: Besu plugins hook into block building to validate transactions
* **Sidecar execution**: Assertions run in the Credible Layer sidecar alongside the node
* **Low-latency flow**: Validation happens during block building and returns a valid/invalid decision

## System Overview

```mermaid theme={null}
---
title: Linea Besu Integration (High Level)
---
flowchart LR
  subgraph BesuNode["Linea Besu Node"]
    TxPool["Transaction Pool"]
    Builder["Block Builder"]
    Plugin["Credible Layer Plugin"]
  end

  subgraph SidecarGroup["Enforcer Sidecar"]
    SidecarSvc["Assertion Enforcer"]
    Engine["Assertion Execution Engine"]
    Store["Assertion Store"]
    SidecarSvc --> Engine
    Engine --> Store
  end

  Registry["Registry Data<br/>(On-Chain Events)"]
  DA["Assertion DA"]

  TxPool --> Builder
  Builder --> Plugin
  Plugin --> SidecarSvc
  SidecarSvc --> Plugin
  SidecarSvc --> Registry
  SidecarSvc --> DA
```

## Validation Flow

1. The block builder selects a candidate transaction.
2. The plugin sends the transaction to the sidecar for assertion validation.
3. The sidecar executes applicable assertions and returns a decision.
4. The block builder includes valid transactions and drops invalid ones.

## Notes

* The plugin uses Besu’s transaction selection hooks to validate transactions during block building.
* The sidecar relies on registry data (from on-chain events) and assertion data to determine applicable assertions.
* This integration does not change core protocol rules; it runs alongside the existing block builder.

## Related Docs

* [Network Integration Overview](/credible/network-integration)
* [Assertion Enforcer](/credible/assertion-enforcer)
* [Assertion DA](/credible/assertion-da)
* [OP Stack](/credible/network-integrations/architecture-op-stack)