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

# Networks and validators

> Mainnet, testnet, and custom networks — how Quantum Chain runs Clique PoA in practice.

Quantum Chain uses **Clique Proof-of-Authority** consensus. A fixed list of approved sealers — set at genesis and updatable through on-chain votes — produces blocks in round-robin.

## Networks

| Network |   Chain ID   | Block time | Notes                            |
| ------- | :----------: | :--------: | -------------------------------- |
| Mainnet |    `20803`   |    15 s    | Production network               |
| Testnet | configurable |   5–15 s   | For staging and integration      |
| Devnet  |      any     |    1–5 s   | Local development; single sealer |

Quantum Chain mainnet genesis is checked into [`configs/mainnet/genesis.json`](configs/mainnet/genesis.json).

## Genesis file structure

```json theme={null}
{
  "config": {
    "chainId": 20803,
    "homesteadBlock": 0,
    "eip150Block": 0,
    "eip155Block": 0,
    "eip158Block": 0,
    "byzantiumBlock": 0,
    "constantinopleBlock": 0,
    "petersburgBlock": 0,
    "istanbulBlock": 0,
    "berlinBlock": 0,
    "londonBlock": 0,
    "quantumVerificationBlock": 0,
    "clique": { "period": 15, "epoch": 30000 }
  },
  "publicKey": "<post-quantum public key bound to genesis>",
  "difficulty": "1",
  "gasLimit": "30000000",
  "extraData": "0x...<32 vanity bytes><20 bytes per sealer>...<65 bytes seal>",
  "alloc": { "0x...": { "balance": "..." } }
}
```

The **`extraData`** field encodes the initial sealer set:

```
[32 bytes vanity] [20 bytes sealer #1] [20 bytes sealer #2] ... [65 bytes signature placeholder]
```

The placeholder is zeroed at genesis. To build it, use the `extradatagenerator` tool:

```bash theme={null}
./build/bin/extradatagenerator \
  --validators 0xAddr1,0xAddr2,0xAddr3 \
  > extra.hex
```

## Initialize a new network

```bash theme={null}
./build/bin/geth --datadir ./node1 init genesis.json
./build/bin/geth --datadir ./node2 init genesis.json
```

`init` writes the genesis block. Run `init` once per data directory; running it again on a populated directory is a no-op.

## Run a validator (Clique sealer)

A validator must be in the sealer set encoded in `extraData`, and must run with `--mine`:

```bash theme={null}
geth \
  --datadir /var/lib/geth \
  --networkid 20803 \
  --syncmode full \
  --mine \
  --miner.etherbase 0xMySealerAddress \
  --unlock 0xMySealerAddress \
  --password /etc/geth/password \
  --port 30303 \
  --maxpeers 25 \
  --metrics --metrics.addr 127.0.0.1
```

Sealers take turns proposing blocks. With period `15s` and `N` sealers, each sealer proposes one block every `15 × N` seconds on average.

## Add or remove a sealer

Sealers vote on changes through the `clique_propose` API. Voting completes when a majority of current sealers agree.

```javascript theme={null}
// Add a sealer
clique.propose("0xNewSealerAddress", true)

// Remove a sealer
clique.propose("0xOldSealerAddress", false)

// Check pending proposals
clique.proposals
```

Votes are tallied at each **epoch** (every 30 000 blocks on mainnet). At an epoch transition, the active sealer set is finalized in the next checkpoint header's `extraData`.

## Inspect the active sealer set

```javascript theme={null}
// Current sealers
clique.getSigners()

// At a specific block
clique.getSignersAtHash("0x...")
```

Or via JSON-RPC:

```bash theme={null}
curl -s -X POST $RPC -H 'Content-Type: application/json' --data '{
  "jsonrpc":"2.0","method":"clique_getSigners","id":1,"params":["latest"]
}'
```

## Static peers

For private networks where discovery is undesirable, hard-code peers in `static-nodes.json` under your `--datadir`:

```json theme={null}
[
  "enode://abc...@10.0.0.1:30303",
  "enode://def...@10.0.0.2:30303"
]
```

Or pass `--bootnodes`.

## Bootnodes

For public networks, run a bootnode:

```bash theme={null}
./build/bin/bootnode -genkey boot.key
./build/bin/bootnode -nodekey boot.key -addr :30301
```

Distribute the resulting `enode://...` URL.

## Operating a private testnet

A typical 3-validator testnet:

1. Generate three keystores with `keygenerator`.
2. Build genesis with `extradatagenerator --validators <3 addresses>`.
3. `geth init` on each node.
4. Connect them via `static-nodes.json`.
5. Start each with `--mine --unlock`.

Block production starts when the first validator runs `--mine` and discovers at least one peer.

## Reorg safety

Clique reorgs are bounded by the sealer-out-of-turn rule and are typically 1–2 blocks. For institutional flows, `Qustody` waits for `CUSTODY_CONFIRMATION_DEPTH` (default 12) blocks before marking a transaction `CONFIRMED`. Increase for high-value transfers.

## Where to go next

* [Configuration](/quantum-chain/configuration)
* [Running a node](/quantum-chain/running-a-node)
* [Configure a development network](/guides/configure-a-development-network)