payload_too_large: the request body is over the per-call allowance

Common causes

• A large JSON body was sent as a single forward.
• A file was base64-encoded into body_base64 — base64 inflates the payload by about a third.
• An automation retried by appending to an existing body rather than replacing it.

How to fix it

1. 01Split the work into several smaller forwards instead of one oversized call.
2. 02Upload large artefacts to your own storage and send the relay a URL instead of the bytes.
3. 03Check the byte count before sending; envelope meta reports bytes_in and bytes_out on successful calls.

What it looks like

# smaller request, same outcome
{
  "url": "https://api.example.com/v1/items",
  "method": "POST",
  "body": { "ids": [1, 2, 3, 4, 5] },
  "timeout_ms": 10000
}

Every error code