{
  "id": "text.empty",
  "category": "request_validation",
  "summary": "The message text is empty.",
  "match_any": [
    {
      "error_code": 400,
      "description_exact": "Bad Request: message text is empty"
    }
  ],
  "scope": {
    "method_examples": [
      "sendMessage",
      "editMessageText"
    ],
    "exhaustive": false
  },
  "possible_causes": [
    "The text argument is absent or empty."
  ],
  "diagnostic_limits": "This validates the message text input; it does not establish a rule for optional media captions.",
  "evidence": [
    {
      "source": "live-2026-09-16",
      "note": "sendMessage with empty text returned this description."
    },
    {
      "source": "server-10.3",
      "path": "telegram-bot-api/Client.cpp",
      "lines": [
        12039,
        12052
      ],
      "note": "Text-message construction rejects empty text before formatting."
    },
    {
      "source": "server-10.3",
      "path": "telegram-bot-api/Client.cpp",
      "lines": [
        13981,
        13993
      ],
      "note": "sendMessage constructs its text with this helper."
    },
    {
      "source": "server-10.3",
      "path": "telegram-bot-api/Client.cpp",
      "lines": [
        13800,
        13803
      ],
      "note": "Method validation errors are passed to the response normalizer."
    },
    {
      "source": "server-10.3",
      "path": "telegram-bot-api/Client.cpp",
      "lines": [
        165,
        205
      ],
      "note": "Adds the code-specific prefix and lowercases only the initial character of ordinary messages."
    }
  ],
  "example": {
    "method": "sendMessage",
    "response": {
      "ok": false,
      "error_code": 400,
      "description": "Bad Request: message text is empty"
    }
  },
  "evidence_level": "observed",
  "guidance": {
    "action": "supply_message_text",
    "repeat_request": "after_relevant_change",
    "preconditions": [
      "Provide nonempty text appropriate for the selected method."
    ]
  }
}