RPC method

debug_traceCall on Core

Supported on SwiftNodes

Measured 2026-10-11 by our weekly probe, which calls debug_traceCall through the same Core endpoint customers use.

What debug_traceCall does

Executes a call against a block's state and returns its execution trace (with a tracer such as callTracer), without sending a transaction. It is the standard way to see what a call would do internally before you submit it.

debug_traceCall on Core: what we measured

Default Core routing keeps state for roughly the last 1,000,000 blocks (about 34.7 days of Core history). Tracing against a block older than that needs historical state. Add &archive=1 to send the request to archive upstreams (paid plans).

Example request

curl -s https://rpc.swiftnodes.io/rpc/core?key=YOUR_API_KEY \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"debug_traceCall","params":[{"to":"0x0000000000000000000000000000000000000000","data":"0x"},"latest",{"tracer":"callTracer"}]}'

import { createPublicClient, http } from "viem";

const client = createPublicClient({ transport: http("https://rpc.swiftnodes.io/rpc/core?key=YOUR_API_KEY") });

// Any JSON-RPC method, typed loosely: debug_traceCall on Core
const result = await client.request({
  method: "debug_traceCall",
  params: [{"to":"0x0000000000000000000000000000000000000000","data":"0x"},"latest",{"tracer":"callTracer"}],
});

Other methods on Core

debug_traceCall on other chains

Support differs by chain; the full measured table is on the debug_traceCall reference.

Frequently asked questions

Does Core support debug_traceCall?

Yes. debug_traceCall answered correctly on the SwiftNodes Core endpoint in our weekly method probe (2026-10-11), which sends real requests through the customer path.

Are there limits on debug_traceCall on Core?

Default Core routing keeps state for roughly the last 1,000,000 blocks (about 34.7 days of Core history). Tracing against a block older than that needs historical state. Add &archive=1 to send the request to archive upstreams (paid plans).

Core endpoints, live block height and WebSocket status are on the Core RPC page.

One key covers every chain we serve, and SwiftNodes has a free tier.