RPC error HTTP 413: Request body over the 64 KiB limit

Last updated: November 1, 2026

At a glance

Cause

Every JSON-RPC element is gated by method and plan, so the gateway has to read the whole body before forwarding it. It reads up to 64 KiB, or 4 MiB on Robinhood Chain, and whitespace counts. A body above that cannot be inspected safely, so it is refused rather than passed on unchecked. The usual cause is a batch built by an indexer or a multicall helper that grew with its input: the code works in tests and starts failing when a real block arrives with more receipts or logs to fetch.

Solution

1. Check the error field: batch_too_large for an array body, request_too_large for a single JSON-RPC object.
2. Split the batch into smaller arrays and send them one after another. Measure the serialized size in bytes, not the element count.
3. Remove what you do not need from the body: long eth_getLogs address lists are a common way to fill 64 KiB with a single element.
4. Use a method that returns a block's data in one call where the network offers one, such as eth_getBlockReceipts, instead of one element per transaction.

const LIMIT = 60 * 1024; // stay under 64 KiB
const chunks = [[]];
let size = 2;
for (const call of calls) {
  const bytes = new TextEncoder().encode(JSON.stringify(call)).length + 1;
  if (size + bytes > LIMIT) { chunks.push([]); size = 2; }
  chunks.at(-1).push(call);
  size += bytes;
}

Example

{
  "error": "batch_too_large",
  "message": "Batch body exceeds the 64 KiB inspection limit; split the batch into smaller requests",
  "chain": "base"
}