core-lightning/doc/schemas/signpsbt.schema.json

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "signed_psbt"
  ],
  "properties": {
    "signed_psbt": {
      "type": "string",
      "description": "The fully signed PSBT"
    }
  }
}