ripple-lib/dist/npm/common/schemas/objects/private-key.json

Deprecated - consider migrating to xrpl.js: https://xrpl.org/xrpljs2-migration-guide.html

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "privateKey",
  "description": "The hexadecimal representation of a secp256k1 or Ed25519 private key.",
  "type": "string",
  "pattern": "^[A-F0-9]+$"
}