debug_traceTransaction

debug_traceTransaction re-executes a transaction that has already been included in a block and records every step of its EVM execution. It is the canonical way to understand why a transaction behaved the way it did — which opcodes ran, how gas was consumed, what state was touched, where it reverted, and the revert reason.

By default the method returns a struct (opcode) log: a step-by-step list of every executed opcode with its program counter, gas, stack, memory, and storage deltas. Because these logs can be very large for complex transactions, you will usually pass a tracer in the options object instead — for example callTracer to get a compact tree of internal calls, or prestateTracer to get the accounts and storage the transaction read. See Tracer options below.

This is a debug-namespace method available on the Pro tier and above. It is rate limited per tier (5 RPS on Pro, 15 RPS on Business) with a short burst allowance; there is no daily quota. Tracing is computationally heavy — keep the opcode-level default reserved for the transactions you genuinely need to inspect, and prefer a focused tracer where possible.

Two positional parameters.

With tracer: "callTracer", the result is the transaction's call tree:

The default struct logger (no tracer) instead returns an object with gas, failed, returnValue, and a structLogs array (one entry per opcode).

See the shared error envelope reference for the full error object shape and handling guidance.

JavaScript (fetch)

const res = await fetch("https://api.triport.io/v1/eth", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.TRIPORT_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    jsonrpc: "2.0",
    id: 1,
    method: "debug_traceTransaction",
    params: [
      "0x5b8d2a3c9f1e7b04c6f2a1d8e3047b9a6c1f0e2d4b8a7c5e9f3a1d2c4b6e8f0a",
      { tracer: "callTracer", tracerConfig: { withLog: true } },
    ],
  }),
});


const { result } = await res.json();
console.log(result.type, result.gasUsed, result.calls?.length ?? 0);

TypeScript SDK (@triport/sdk)

import { Triport } from "@triport/sdk";


const triport = new Triport({ apiKey: process.env.TRIPORT_API_KEY! });


const trace = await triport.eth.request("debug_traceTransaction", [
  "0x5b8d2a3c9f1e7b04c6f2a1d8e3047b9a6c1f0e2d4b8a7c5e9f3a1d2c4b6e8f0a",
  { tracer: "callTracer", tracerConfig: { onlyTopCall: false } },
]);


console.log(trace.gasUsed);

Python (triport-sdk)

import os
from triport import Triport


triport = Triport(api_key=os.environ["TRIPORT_API_KEY"])


trace = triport.eth.request(
    "debug_traceTransaction",
    [
        "0x5b8d2a3c9f1e7b04c6f2a1d8e3047b9a6c1f0e2d4b8a7c5e9f3a1d2c4b6e8f0a",
        {"tracer": "callTracer", "tracerConfig": {"withLog": True}},
    ],
)
print(trace["type"], trace["gasUsed"])

• Pick the smallest tracer that answers your question. callTracer is the right default for "what calls did this transaction make and where did it revert"; reach for the opcode-level struct logger only when you need step-by-step EVM detail, and use disableStack / disableStorage to keep the payload manageable.
• The transaction must already be mined. To trace a hypothetical call that has not been sent, use debug_traceCall instead; to trace every transaction in a block, use debug_traceBlockByNumber or debug_traceBlockByHash.
• callTracer results are returned for the whole transaction as a single tree; set tracerConfig.onlyTopCall: true if you only need the outermost frame.
• Raise timeout (e.g. "30s") for unusually deep or compute-heavy transactions whose default 5-second trace would otherwise be aborted.