Run a Robinhood Chain full node

Robinhood Chain is an Arbitrum Chain running Arbitrum Nitro. This guide walks through deploying and syncing your own full node.

Running a node is time consuming, resource intensive, and potentially costly. If you don't already know why you need your own node, you probably don't.

If you just need an RPC endpoint, use the public endpoints or a provider:

• Public Mainnet: https://rpc.mainnet.chain.robinhood.com
• Alchemy: https://robinhood-mainnet.g.alchemy.com/v2/{API_KEY}

Download the config files for your target network:

• Mainnet: chain info robinhood-chain-info.json and genesis robinhood-genesis.json
• Testnet: chain info robinhood-chain-testnet-info.json

Testnet does not use a custom genesis file, so its start command omits the --init.genesis-json-file flag.

Hardware requirements

Prerequisites

Because Robinhood Chain posts its data to Ethereum, your node needs access to an Ethereum (L1) endpoint — your own or via a provider.

You need both:

• An L1 execution RPC endpoint
• An L1 beacon (consensus) endpoint — required to read blob data

If you run your own L1 node, it must be fully synced before Robinhood Chain can finish syncing.

You'll also need Docker installed and running.

Running the node

Start the node with Docker, supplying your L1 endpoints and the Robinhood Chain config. The commands differ by network: Mainnet initializes from a custom genesis file, while Testnet does not.

Place the config files you downloaded above into a local directory (e.g. $HOME/rh/config) and mount it into the container at /home/nitro/config, which the commands reference. Mount your data directory to /home/nitro/.arbitrum — the nitro-node image runs as the nitro user, so mounting elsewhere leaves the node unable to persist chain data. Substitute your own L1 endpoints for parent-chain.connection.url and parent-chain.blob-client.beacon-url.

Mainnet

DATA_DIR="$HOME/rh/robinhood-nitro-data"
docker run --rm -it \
    -v "$DATA_DIR":/home/nitro/.arbitrum \
    -v "$HOME/rh/config":/home/nitro/config \
    -p 8547:8547 -p 8548:8548 \
    offchainlabs/nitro-node:v3.11.2-3599aca \
      --chain.info-files=/home/nitro/config/robinhood-chain-info.json \
      --parent-chain.connection.url=... \
      --parent-chain.blob-client.beacon-url=... \
      --init.genesis-json-file=/home/nitro/config/robinhood-genesis.json \
      --http.addr=0.0.0.0 --http.port=8547 \
      --http.api=net,web3,eth

To subscribe to the sequencer feed for low-latency updates, add --node.feed.input.url=wss://feed.mainnet.chain.robinhood.com. The feed URL must be wss://, not https://.

Testnet

Testnet has no custom genesis, so its start command omits the --init.genesis-json-file flag.

DATA_DIR="$HOME/rh/robinhood-nitro-data"
docker run --rm -it \
    -v "$DATA_DIR":/home/nitro/.arbitrum \
    -v "$HOME/rh/config":/home/nitro/config \
    -p 8547:8547 -p 8548:8548 \
    offchainlabs/nitro-node:v3.11.2-3599aca \
      --chain.info-files=/home/nitro/config/robinhood-chain-testnet-info.json \
      --parent-chain.connection.url=... \
      --parent-chain.blob-client.beacon-url=... \
      --http.addr=0.0.0.0 --http.port=8547 \
      --http.api=net,web3,eth

For the testnet sequencer feed, add --node.feed.input.url=wss://feed.testnet.chain.robinhood.com.

Once running, confirm the node responds:

curl -d '{"id":0,"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["latest",false]}' \
  -H "Content-Type: application/json" http://localhost:8547

Initial sync can take a long time and will consume significant L1 request quota — monitor your L1 provider usage.

Running a validator

Robinhood Chain utilizes BoLD for dispute resolution through a permissioned set of validators. Operating a validator necessitates being included in the allowlist and staking a 1 WETH bond (defensive validators are highly encouraged). Reach out to Robinhood to become part of the validator set.

Syncing

Check sync progress with eth_syncing. A fully synced node returns false:

curl -d '{"id":0,"jsonrpc":"2.0","method":"eth_syncing","params":[]}' \
  -H "Content-Type: application/json" http://localhost:8547

You can also watch the node logs for block production messages.

If you try to send transactions before the node is fully synced, you may see nonce has already been used — wait for sync to complete.

Faster sync (optional): to skip syncing from genesis, initialize from a snapshot by adding --init.url=<SNAPSHOT_URL> on first start.

Node configuration

Robinhood Chain requires the chain info file provided by Robinhood, passed to the node via --chain.info-files (see Running the node). On Mainnet, also pass the custom genesis configuration via --init.genesis-json-file; Testnet does not use a custom genesis.

Robinhood Chain runs ArbOS 61. Confirm the current Nitro/ArbOS version before starting. On ArbOS upgrades, un-upgraded nodes stop cleanly and resume after updating — with no data loss.

Troubleshooting

General checks

• View logs via docker logs -f <container> to identify errors.
• Confirm the container status is healthy and not in a restart loop.
• Verify network connectivity to L1 execution and beacon endpoints from the host.
• Confirm your L1 node is fully synced; an unsynced L1 will stall L2 syncing.

Syncing issues

• Check the L1 connection and beacon URL; most failures are due to unreachable beacon endpoints.
• Ensure the server clock is accurate using ntp or chrony.

Sync is slow:

• Verify disk I/O performance; networked storage will significantly throttle sync speed.

Connectivity issues

• Verify container ports (8547 for HTTP, 8548 for WS) are correctly mapped and open.
• Ensure --http.addr=0.0.0.0 is set to allow external RPC access.

Support

Robinhood Chain Support