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Tempo API method that replays all transactions in a block and returns execution traces for each. This is useful for detailed analysis of block execution with customizable trace options.

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Parameters

  • blockParameter — the block number (hex) or tag (latest, earliest, pending)
  • traceTypes — array of trace types to include:
    • trace — basic execution trace
    • vmTrace — full VM execution trace
    • stateDiff — state changes

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Response

  • result — array of trace results, one per transaction:
    • output — return data from the transaction
    • trace — array of trace objects (if requested)
    • vmTrace — VM execution trace (if requested)
    • stateDiff — state differences (if requested)
    • transactionHash — hash of the transaction

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trace_replayBlockTransactions code examples

const ethers = require('ethers');
const NODE_URL = "CHAINSTACK_NODE_URL";
const provider = new ethers.JsonRpcProvider(NODE_URL);

const replayBlock = async (blockNumber) => {
    const results = await provider.send("trace_replayBlockTransactions", [
      blockNumber,
      ["trace"]
    ]);

    console.log(`Replayed ${results.length} transactions`);

    for (let i = 0; i < results.length; i++) {
      const result = results[i];
      console.log(`\nTransaction ${i}: ${result.transactionHash}`);
      console.log(`  Output: ${result.output}`);
      console.log(`  Traces: ${result.trace?.length || 0}`);

      if (result.trace && result.trace.length > 0) {
        for (const trace of result.trace) {
          const callType = trace.action.callType || trace.type;
          console.log(`    ${callType}: ${trace.action.from} -> ${trace.action.to || 'Create'}`);
        }
      }
    }
  };

replayBlock("latest");