# Dev Chain

A dev chain is a local, private network useful for smart contract development, testing RPC calls, and experimenting with Erigon configuration without connecting to a public network.

## Quick Start

```bash
./erigon \
  --datadir=dev \
  --chain=dev \
  --mine \
  --http.api=eth,erigon,web3,net,debug,trace,txpool,parity,admin \
  --http.corsdomain="*"
```

Key flags:

| Flag                          | Purpose                                                                                                          |
| ----------------------------- | ---------------------------------------------------------------------------------------------------------------- |
| `--chain=dev`                 | Run a local dev chain                                                                                            |
| `--datadir=dev`               | Store chain data in the `dev/` folder                                                                            |
| `--mine`                      | Enable block production                                                                                          |
| `--dev.period <seconds>`      | Block interval in seconds. Must be > 0 to mine empty blocks (default: 0, mines only when there are transactions) |
| `--miner.etherbase <address>` | Coinbase address that receives block rewards. Defaults to a pre-funded dev account if not set.                   |
| `--miner.gaslimit <value>`    | Gas limit target for mined blocks (default: `30000000`).                                                         |
| `--miner.extradata <hex>`     | Extra data field appended to mined blocks (up to 32 bytes).                                                      |

## Running Multiple Nodes

To connect two local nodes, save the `enode://` address printed at startup of node 1 and pass it to node 2 via `--staticpeers`.

```bash
# Node 1
./erigon --datadir=dev1 --chain=dev --mine --port=30303

# Node 2 (uses node 1's enode as static peer)
./erigon --datadir=dev2 --chain=dev --port=30304 \
  --staticpeers="enode://<NODE1_PUBKEY>@127.0.0.1:30303"
```

## Full Tutorial

For a complete step-by-step walkthrough including RPC daemon setup and multi-node configuration, see [DEV\_CHAIN.md](https://github.com/erigontech/erigon/blob/main/docs/DEV_CHAIN.md) in the repository.