eth_syncing

eth_syncing reports whether a Base node is still catching up to the chain head or has fully synced. Base is Coinbase's OP Stack optimistic rollup that settles to Ethereum and meters gas in ETH, with the sequencer producing blocks about every two seconds — so a node that is behind has to replay a lot of recent history before it can serve accurate state. When the node is fully synced this call returns false; while it is still importing blocks it returns an object whose startingBlock, currentBlock, and highestBlock fields (all hex) let you watch progress toward the tip. Send the request to https://base.therpc.io/YOUR_API_KEY against chain ID 8453 (hex 0x2105).

Use cases

• Verify a freshly started Base node has caught up to the head before routing user traffic to it, so reads never return stale OP Stack state.
• Display a sync-progress percentage in a node dashboard by comparing currentBlock against highestBlock as the node climbs toward the tip.
• Gate application startup on sync completion — block your Base service from accepting requests until eth_syncing returns false.
• Diagnose a stuck or slow node by polling currentBlock over time; on Base's ~2-second cadence a healthy node should advance several blocks between samples, and a flat value flags a stall.

Parameters

Cette méthode ne prend aucun paramètre. Passez un tableau vide [].

Response

Example request

1curl https://base.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "eth_syncing",
7    "params": [],
8    "id": 1
9  }'

Try it live in the Base playground.

Errors & troubleshooting

Common pitfalls

• Some clients return false during certain sync phases even when the node is not truly at the head (for example Beam Sync on Nethermind). Do not treat false as an absolute guarantee — cross-check eth_blockNumber against the public Base height on basescan.org.
• On Base this reports execution-layer sync only. The OP Stack rollup node (op-node) tracks L1 derivation separately, so a fully-synced execution layer does not by itself confirm the consensus/derivation layer is current.
• The returned object's shape is client-specific — Geth, Erigon, and others add different extra fields — so code that reads beyond startingBlock/currentBlock/highestBlock should handle missing keys gracefully.

Supported networks

• Mainnet — Chain ID: 8453
• Sepolia — Chain ID: 84532

See also

• eth_blockNumber
• eth_chainId
• net_peerCount

1curl https://base.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"eth_syncing","params":[]}'