Trace a BSC Block Builder Bundle — eth_traceBundle

The eth_traceBundle method returns a detailed execution trace for a bundle that was previously submitted to BlockRazor’s BSC Block Builder via eth_sendBundle. Using the bundleHash returned at submission time, you can inspect exactly how each transaction in the bundle executed: which opcodes ran, how much gas was consumed at each step, which events were emitted, and whether any transaction encountered a revert and why. This level of visibility is essential for debugging failed bundles, verifying profitability, and auditing execution paths post-inclusion.

Bundle tracing via eth_traceBundle is available to registered users on BSC. See Pricing for full subscription tier details.

Endpoint

POST https://builder.blockrazor.io/bsc

Authentication is performed via a Bearer token passed in the Authorization header.

Request

The request follows the standard JSON-RPC 2.0 envelope. The single element of params is a trace request object containing the bundle hash to look up.

Trace Parameters

bundleHash

string

required

The hash of the bundle to trace, as returned by eth_sendBundle at submission time. This uniquely identifies the bundle within BlockRazor’s Block Builder and is used to retrieve the stored execution trace.

Code Examples

curl -X POST https://builder.blockrazor.io/bsc \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer YOUR_AUTH_TOKEN' \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_traceBundle",
    "params": [
      {
        "bundleHash": "0x7f3a9c2e1d4b..."
      }
    ],
    "id": 1
  }'

Response

The response contains an array of trace objects—one per transaction in the original bundle—each containing full execution detail.

result

object[]

An array of per-transaction trace objects in the same order as the original bundle’s txs array.

Show Per-Transaction Trace Fields

txHash

string

The hash of this transaction within the bundle.

blockNumber

string

The hex-encoded block number in which this bundle was included. Returns null if the bundle has not yet been included in a block.

gasUsed

integer

The total amount of gas consumed by this transaction during execution. Useful for reconciling against your pre-submission simulation results from eth_callBundle.

status

string

Execution status of the transaction. "success" indicates the transaction completed without reverting; "reverted" indicates it reverted.

revertReason

string

Present only when status is "reverted". Contains the decoded revert reason string or raw revert data from the EVM. Use this to identify which contract condition caused the revert.

logs

object[]

An array of EVM log (event) objects emitted by this transaction.

Show Log Object Fields

address

string

The contract address that emitted this log.

topics

string[]

An array of 32-byte indexed topic values. The first topic is typically the keccak256 hash of the event signature.

data

string

The non-indexed log data encoded as a hex string. Decode using the emitting contract’s ABI to extract event parameters.

calls

object[]

An array of internal call trace objects representing sub-calls made during this transaction’s execution (e.g., calls from one contract to another).

Show Call Trace Object Fields

type

string

The call type: "CALL", "STATICCALL", "DELEGATECALL", or "CREATE".

from

string

The address of the caller.

string

The address of the callee.

value

string

The amount of BNB (in wei, as a hex string) transferred with this call. "0x0" for non-payable calls.

gasUsed

integer

Gas consumed by this specific internal call.

input

string

The calldata sent to the callee, encoded as a hex string.

output

string

The return data from the callee, encoded as a hex string.

Response Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    {
      "txHash": "0xabc123def456...",
      "blockNumber": "0xE4E1C0",
      "gasUsed": 84200,
      "status": "success",
      "logs": [
        {
          "address": "0xContractAddress...",
          "topics": [
            "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
            "0x000000000000000000000000SenderAddress",
            "0x000000000000000000000000ReceiverAddress"
          ],
          "data": "0x0000000000000000000000000000000000000000000000000de0b6b3a7640000"
        }
      ],
      "calls": [
        {
          "type": "CALL",
          "from": "0xYourAddress...",
          "to": "0xRouterAddress...",
          "value": "0x0",
          "gasUsed": 72000,
          "input": "0x38ed1739...",
          "output": "0x00000000..."
        }
      ]
    },
    {
      "txHash": "0xfed987cba321...",
      "blockNumber": "0xE4E1C0",
      "gasUsed": 24100,
      "status": "reverted",
      "revertReason": "execution reverted: insufficient output amount",
      "logs": [],
      "calls": []
    }
  ]
}

Using Trace Data Effectively

Trace data from eth_traceBundle provides the ground truth of what happened on-chain, making it the authoritative source for post-execution analysis.

eth_traceBundle only returns data for bundles submitted through BlockRazor’s Block Builder. Bundles submitted via the Bundle endpoint (bundle.blockrazor.io) are not traceable through this method—use it in conjunction with eth_sendBundle on the builder.blockrazor.io endpoint.

Cross-reference gasUsed in the trace with the values returned by eth_callBundle simulation. Significant discrepancies indicate that chain state changed between simulation and block inclusion, which can reveal why a bundle behaved differently than expected.

RPC

Fast

Bundle

Streams

Block Builder

Trace a BSC Block Builder Bundle — eth_traceBundle

Endpoint

Request

Trace Parameters

Code Examples

Response

Using Trace Data Effectively

Build docs developers (and LLMs) love

RPC

Fast

Bundle

Streams

Block Builder

Documentation Index

​Endpoint

​Request

​Trace Parameters

​Code Examples

​Response

​Using Trace Data Effectively

Build docs developers (and LLMs) love

Endpoint

Request

Trace Parameters

Code Examples

Response

Using Trace Data Effectively