{
"kind": "payload_envelope",
"expect": "invalid",
"expect_error": "empty sentinel string in field `payload.payload_kind`",
"description": "empty payload_kind must be rejected — empty sentinels are never legal",
"data": {
"schema_version": "lifeloop.v0.2",
"payload_id": "pay-1",
"client_id": "ccd",
"payload_kind": "",
"format": "client-defined",
"content_encoding": "utf8",
"body": "x",
"byte_size": 1,
"acceptable_placements": [
{ "placement": "pre_prompt_frame", "requirement": "required" }
]
}
}