too_many_headers

HTTP 431 · code too_many_headers · limit MaxHeaders

The request has more header fields than the server accepts.

When Photon sends it

Sent before routing when the number of header fields exceeds MaxHeaders (100 by default). Every field counts, so a thousand copies of one header are a thousand fields.

What the client should do

Send fewer headers. Large cookie jars are the usual cause.

What the server owner can do

Raise MaxHeaders in photon.Limits if legitimate clients need more.

Example response

{
  "type": "https://photon.agenticmarket.dev/errors/too_many_headers",
  "title": "the request has too many header fields",
  "status": 431,
  "code": "too_many_headers",
  "limit": "MaxHeaders"
}

Match on the code field rather than on title, which is meant for people and may change. See all error codes.