Run a Node (for Node Operators)

How to run an ethgas-node with flashblocks enabled, so it serves pre-confirmed state at the pending tag. Flashblocks are off by default. Without a flashblocks feed the node behaves as an ordinary Ethe

Run it

git clone https://github.com/ethgas-developer/ethgas-reth.git
cd ethgas-reth
cargo build --release --bin ethgas-node

./target/release/ethgas-node node \
  --chain hoodi \
  --flashblocks-url wss://hoodi.flashblocks.ethgas.com/ws \
  --engine.persistence-threshold 0 \
  --engine.memory-block-buffer-target 0 \
  --http --http.api eth,net,web3 \
  --ws --ws.api eth,net,web3

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Flashblocks flags

Flag	Description	Default
--flashblocks-url <URL>	WebSocket endpoint streaming flashblocks. Alias --websocket-url. Setting it enables the feature	disabled
--max-pending-blocks-depth <N>	Pending blocks held in memory	3
--flashblocks.ping-interval <DUR>	Ping interval, and also the pong deadline. A dead feed is detected after at most two intervals. Requires --flashblocks-url	2s

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Flashblocks endpoints

Point --flashblocks-url at the endpoint for the network you are running.

Network	Endpoint
Mainnet	wss://mainnet.flashblocks.ethgas.com/ws
Hoodi	wss://hoodi.flashblocks.ethgas.com/ws

These are node infrastructure, not application endpoints. Your users should query your RPC. Do not point an application at the stream directly, and do not expose it to them.

Serve WebSocket as well as HTTP. The flashblock subscriptions need --ws. They cannot be served over HTTP.

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The two engine flags

--engine.persistence-threshold 0 and --engine.memory-block-buffer-target 0 are not cosmetic. They make the node persist blocks immediately rather than hold them in memory, which is what keeps pre-confirmed state anchored to the block it was built on. Running with the defaults risks pending silently falling back to the latest confirmed block.