# AERE Network, second execution client

These are the AERE Network additions to [Nethermind](https://github.com/NethermindEth/nethermind),
the second execution client for AERE chain 2800. They are not a complete client: they are the files
that had to be added or changed so that an independent implementation, written in a different
language on a different codebase, can follow chain 2800 and reach the same state.

## Why a second client exists

Chain 2800 produces every block with Hyperledger Besu today. A consensus bug in Besu would produce a
wrong block and nothing in the validator set would stop it, because every validator runs the same
code. A second implementation is the only thing that can disagree.

That is the whole point of this repository, and it is also the honest limit of what it achieves so
far: **this client follows and validates, it does not produce blocks on mainnet.** Client diversity
in production does not exist on chain 2800 yet.

## What is here

- **`Nethermind.AerePqc/Precompiles/`** — the five post-quantum verifiers live on chain 2800 since
  block 9,189,161: Falcon-512, Falcon-1024, ML-DSA-44, SLH-DSA-128s and SHAKE256. They wrap the
  Bouncy Castle implementations already on the client classpath; no cryptography is hand-rolled here.
- **`Nethermind.AerePqc/Qbft/`** — QBFT header decoding, extra-data handling and the header hashing
  rule, written independently rather than ported, so that agreement between the two clients is
  evidence rather than a shared assumption.
- **`Nethermind.AerePqc/Consensus/`** — header and seal validation for the AERE variant of QBFT.
- **`Nethermind.Consensus.Ethash/AereBaseFeeCalculator.cs`** — the AERE base-fee floor, active from
  block 10,141,734 with a 1 Gwei floor.
- **`Nethermind.Core/AereFloorLapse.cs`** — the one historical range in which chain 2800 did not
  apply its own floor. Read that file: it explains what happened, why the exception belongs at
  validation rather than in the calculation, and how the bounds were measured.
- **tests** — including the two that matter most, the follower proof against real chain-2800 headers
  and the base-fee floor fork tests.

## What this repository does not contain

The full Nethermind client. Get it from upstream and apply these files on top. Nothing here is
useful on its own.

It also contains no keys, no node addresses, and no operational configuration, by design.

## Licence

The files carry `SPDX-License-Identifier: LGPL-3.0-only`, inherited from the Nethermind sources they
derive from. See `LICENSE`. Upstream Nethermind is the authority on its own licensing; if you are
redistributing, check the upstream terms as well as these.

## Status, stated plainly

- follows and validates chain 2800: yes
- produces mainnet blocks: no
- reached consensus with Besu as an equal validator: on an isolated testnet only
- audited by a third party: no