debug_traceTransaction

debug_traceTransaction replays a transaction that has already been mined on Base and returns its execution at opcode level, reproducing the exact EVM state at the block where it landed. Base is Coinbase's OP Stack optimistic rollup that meters gas in ETH and settles to Ethereum L1, so a trace here walks the same struct-log or tracer output you would expect from a Geth-based client. Give the call the transaction hash and an optional tracer config at https://base.therpc.io/YOUR_API_KEY (chain ID 8453, hex 0x2105); the node re-executes the transaction against the historical state and reports every step. The default tracer yields a struct-log array, while callTracer and prestateTracer give a call tree or a pre-execution account map instead.

Use cases

• Determine why a Base contract call reverted by inspecting the exact opcode and stack state at the REVERT instruction — for example a failed swap on Aerodrome or Uniswap.
• Profile per-opcode gas consumption to find hot spots worth optimizing, which matters even on Base where ETH gas is cheap but L1 data costs add up.
• Reconstruct the full internal call tree of an MEV bundle on Base using callTracer to see exactly how the bundle moved value between contracts.
• Capture the pre-execution account and storage state with prestateTracer for a security post-mortem after an exploit on a Base protocol.

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": "debug_traceTransaction",
7    "params": [
8        "0x0000000000000000000000000000000000000000000000000000000000000000",
9        {}
10      ],
11    "id": 1
12  }'

Try it live in the Base playground.

Errors & troubleshooting

Common pitfalls

• Any Base transaction older than the most recent few thousand blocks needs an archive node; a pruned node has dropped the state and returns "transaction not found" for the trace.
• The default struct-log output can reach hundreds of megabytes for a complex Base transaction; switch to a compact tracer like callTracer or disable stack and storage in the options object.
• Custom JavaScript tracers run inside a sandboxed interpreter and can hit the configured timeout on a long-running Base transaction — raise the timeout or simplify the tracer if it aborts.

Supported networks

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

See also

• debug_traceCall
• debug_traceBlockByHash
• trace_transaction
• trace_replayTransaction

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":"debug_traceTransaction","params":["",{}]}'