Client Setting Requirements

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Supported JSON RPC Clients

BlockScout currently supports Geth, Erigon, Nethermind, Reth, Besu, RSKj, Lotus, and Anvil JSON RPC clients. To define the JSON RPC node variant, it's advised to define the ETHEREUM_JSONRPC_VARIANT environment variable*. Correct values include:

JSON RPC Client	Value	Note
Geth	`geth`	Default. This value is applicable for both Geth and Reth JSON RPC clients
Erigon	`erigon`	It is suggested to use erigon variant for Reth JSON RPC client.
Nethermind	`nethermind`	This value is applicable for Reth and deprecated OpenEthereum (aka Parity) JSON RPC clients
Besu	`besu`
RSKj	`rsk`
Lotus	`filecoin`
Anvil	`anvil`

*If the variable is not set, JSON RPC variant will be chosen based on CHAIN_TYPE variable according to the mapping https://github.com/blockscout/blockscout/blob/a2625803c831fb86e38ffe0e28d94bfd697914ce/apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/variant.ex#L114-L120

  defp get_default_variant do
    case Application.get_env(:explorer, :chain_type) do
      :rsk -> "rsk"
      :filecoin -> "filecoin"
      _ -> "geth"
    end
  end

BlockScout currently requires a full archive node in order to import every state change for every address on the target network.

Configs

Application	Environment	Config path
Explorer	Dev	https://github.com/blockscout/blockscout/tree/master/apps/explorer/config/dev
	Prod	https://github.com/blockscout/blockscout/tree/master/apps/explorer/config/prod
Indexer	Dev	https://github.com/blockscout/blockscout/tree/master/apps/indexer/config/dev
	Prod	https://github.com/blockscout/blockscout/tree/master/apps/indexer/config/prod

Variables to connect to JSON RPC client

Name	Environment Variable	Default Value	Description
HTTP Endpoint	ETHEREUM_JSONRPC_HTTP_URL	http://localhost:8545	The HTTP Endpoint is used to fetch blocks, transactions, receipts, coin/token balances.
Fallback HTTP Endpoint	ETHEREUM_JSONRPC_FALLBACK_HTTP_URL	(empty)	Fallback JSON RPC HTTP url.
Tracing Endpoint	ETHEREUM_JSONRPC_TRACE_URL	http://localhost:8545	The Tracing endpoint is used to fetch internal transactions and block traces. In most cases this endpoint is identical to the HTTP Endpoint.
Fallback Tracing Endpoint	ETHEREUM_JSONRPC_FALLBACK_TRACE_URL	(empty)	Fallback JSON RPC tracing url.
Eth_call Requests Endpoint	ETHEREUM_JSONRPC_ETH_CALL_URL	(empty)	JSON RPC url for eth_call method requests.
Fallback Eth_call Requests Endpoint	ETHEREUM_JSONRPC_FALLBACK_ETH_CALL_URL	(empty)	Fallback JSON RPC eth_call url.
WebSockets Endpoint	ETHEREUM_JSONRPC_WS_URL	ws://localhost:8546	The WebSockets endpoint subscribes to newHeads which alerts the indexer to fetch the new block from the subscription.

Geth

More information on Geth JSON-RPC is available here.

sudo /usr/bin/geth --http --http.addr 0.0.0.0 --port 30303 --http.port 8545 --http.api debug,net,eth,shh,web3,txpool --ws.api "eth,net,web3,network,debug,txpool" --ws --ws.addr 0.0.0.0 --ws.port 8546 --ws.origins "*" --sepolia --datadir=/rinkeby --syncmode "full" --gcmode "archive" --http.vhosts "*"

Tracing and pruning: By default, state for the last 128 blocks kept in memory. Most states are garbage collected. If you are running a block explorer or other service relying on transaction tracing without an archive node (--gcmode=archive), you need to trace within this window! Alternatively, specify the "reexec" tracer option to allow regenerating historical state; and ideally switch to chain tracing which amortizes overhead across all traced blocks.

Erigon

More information on Erigon configuration is available here.

Nethermind

More information on Nethermind configuration is available here.

Reth

More information on Reth configuration is available here.

RSKj

More information on RSKj configuration is available here.

Besu

More information on Besu configuration is available here.

Lotus

More information on Lotus configuration is available here.

OpenEthereum

--jsonrpc-interface all --jsonrpc-apis web3,eth,net,parity,pubsub,traces --ws-interface all --fat-db=on --pruning=archive --ws-apis all --ws-origins all --ws-hosts all