Tracing100 CUFree key required

debug_traceBlockByNumber on Ethereum

Returns execution traces for all transactions in a block. Used by analytics pipelines reconstructing internal transfers and call trees. Heavy; needs a free API key.

Output and cost scale with block activity, so it can be very large on busy chains. Use callTracer to reconstruct internal transfers and process block-by-block rather than requesting wide ranges.

Ethereum endpoint (keyed — free)

https://rpc.nodeflare.app/eth/v1/YOUR_KEY

Method

debug_traceBlockByNumber

Cost

100 CU

Chain ID

1

Block time

~12 s

Finality

~13 min (finalized)

Tracing on Ethereum

Traces on mainnet are heavy — a single debug_traceTransaction re-executes the transaction. Use the callTracer preset to decode reverts cheaply instead of the default opcode-level struct logger.

Parameters

[blockNumber|tag, { tracer }]

cURL

curl https://rpc.nodeflare.app/eth/v1/YOUR_KEY \
  -X POST \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","method":"debug_traceBlockByNumber","params":["latest", {"tracer": "callTracer"}],"id":1}'

ethers.js

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider(
  'https://rpc.nodeflare.app/eth/v1/YOUR_KEY'
);

const result = await provider.send('debug_traceBlockByNumber', ["latest", {"tracer": "callTracer"}]);

Try it live

Runs the example above against the public Ethereum endpoint — straight from your browser.

debug_traceBlockByNumber on Ethereum — FAQ

How do I call debug_traceBlockByNumber on Ethereum?

POST a JSON-RPC 2.0 request with "method": "debug_traceBlockByNumber" to NodeFlare's Ethereum endpoint at https://rpc.nodeflare.app/eth/v1/YOUR_KEY. This method requires a free API key — it is not available on the public endpoint.

What does debug_traceBlockByNumber cost on the free tier?

debug_traceBlockByNumber is weighted at 100 compute units per call. The free tier includes 2,000,000 CU/month, so that is roughly 20,000 debug_traceBlockByNumber calls per month — no credit card.

Is debug_traceBlockByNumber available on the public Ethereum endpoint?

No. debug_traceBlockByNumber is a heavy method and requires a free API key. The public no-key endpoint serves standard read methods; create a free key to unlock debug_traceBlockByNumber, eth_getLogs, trace_* and debug_*.

Anything Ethereum-specific to know when using debug_traceBlockByNumber?

Traces on mainnet are heavy — a single debug_traceTransaction re-executes the transaction. Use the callTracer preset to decode reverts cheaply instead of the default opcode-level struct logger.

Call debug_traceBlockByNumber on Ethereum with a free key

2,000,000 compute units/month, heavy methods unlocked, every chain included. No credit card.

Get your free API key →