trace_block

trace_block returns the OpenEthereum-style call-tree traces for every transaction in a single Base block, flattened into one array. Base is the OP Stack optimistic rollup Coinbase runs, with roughly two-second blocks, ETH as the gas token, and settlement to Ethereum L1. Address the block by number or by a tag such as latest and send the request to https://base.therpc.io/YOUR_API_KEY (chain ID 8453, hex 0x2105). The node returns each call, create, and self-destruct action across the whole block, with a transactionPosition field on every entry so you can tell which transaction it came from. This is the trace-namespace way to capture all of a Base block's internal activity in one round trip.

Use cases

• Extract every internal transaction in a Base block for an indexer or analytics pipeline, including ETH transfers that emit no event log.
• Analyze MEV activity across all transactions in a specific Base block, spotting arbitrage and sandwich patterns around Aerodrome and Uniswap pools.
• Track value flowing into and out of a contract for an entire Base block by filtering the flat trace array on the addresses you care about.

Parameters

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": "trace_block",
7    "params": ["latest"],
8    "id": 1
9  }'

Try it live in the Base playground.

Errors & troubleshooting

Common pitfalls

• The call returns every trace for every transaction, so a high-throughput Base block (the chain regularly fills with consumer-app traffic) can produce a very large response.
• It requires a trace-enabled archive node; many plain RPC endpoints do not expose the trace namespace at all.
• Avoid the pending tag for production data — a pending Base block can still change before it is finalized, so the traces you read may not match the canonical block.

Supported networks

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

See also

• trace_transaction
• trace_filter
• trace_replayBlockTransactions
• debug_traceBlockByNumber

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":"trace_block","params":["latest"]}'