Format entity not object · format.entity_not_object

Stable ID: format.entity_not_object · Evidence: source derived

An item in the message entities array is not a JSON object.

This identifies an item-shape failure, not invalid offsets, lengths, or markup syntax.

When it matches

Every field in a rule must match. Alternative rules are joined with OR. Codes below are JSON response fields, not inferred HTTP statuses.

• JSON error_code: 400.

Exact description:

Bad Request: can't parse MessageEntity: expected an Object

See matching rules for parameter precedence and unknown or ambiguous results.

Illustrative methods: sendMessage, editMessageText, sendPhoto.

Possible causes

• An entities or caption_entities array contains a non-object item.

Before deciding what to do

Application decision: correct entity objects. Repeat request: after relevant change.

• Provide each entity as an object with the fields required by its type, using the API’s UTF-16 offset convention.

These are application choices. Errorgram does not retry, suppress the error, or change bot state.

Facts

This condition adds no extracted facts; result.facts is empty.

Example

Synthetic examples derived from the cited source.

API method: sendMessage.

{
  "ok": false,
  "error_code": 400,
  "description": "Bad Request: can't parse MessageEntity: expected an Object"
}

Python

from errorgram import classify

response = {
    "ok": False,
    "error_code": 400,
    "description": "Bad Request: can't parse MessageEntity: expected an Object",
}
result = classify(response, method='sendMessage')

assert result.id == 'format.entity_not_object'
print(result.entry["summary"])

JavaScript and TypeScript

import { classify } from "errorgram";

const response = {
  "ok": false,
  "error_code": 400,
  "description": "Bad Request: can't parse MessageEntity: expected an Object"
};
const result = classify(response, { method: "sendMessage" });

if (result.status === "matched" && result.id === "format.entity_not_object") {
  console.log(result.entry.summary);
}

Framework names

Integration	Type or ID
Python	errorgram.FormatEntityNotObject
aiogram	errorgram.aiogram.FormatEntityNotObject extends TelegramBadRequest
grammY	EnrichedGrammyError with classification.id equal to format.entity_not_object

Enrichment is explicit and keeps framework catch compatibility. Follow the Python and aiogram guide or JavaScript, TypeScript, and grammY guide.

Evidence

• Bot API 10.3 · telegram-bot-api/Client.cpp:11938–11946. Entity parsing rejects a non-object item before reading its fields. Revision e3e9dd8e5b3d7ab8537cd5a10dc31d5ffa8f82d1.
• Bot API 10.3 · telegram-bot-api/Client.cpp:11984–11989. The formatting helper wraps the item error in the MessageEntity description with code 400. Revision e3e9dd8e5b3d7ab8537cd5a10dc31d5ffa8f82d1.
• Bot API 10.3 · telegram-bot-api/Client.cpp:13800–13803. Method validation errors are passed to the response normalizer. Revision e3e9dd8e5b3d7ab8537cd5a10dc31d5ffa8f82d1.
• Bot API 10.3 · telegram-bot-api/Client.cpp:165–205. Adds the code-specific prefix and lowercases only the initial character of ordinary messages. Revision e3e9dd8e5b3d7ab8537cd5a10dc31d5ffa8f82d1.

Source references identify the reviewed revision, not the first release that introduced this response.

Data and versions

Catalogue 0.1.0 · schema 1.0.0 · reviewed 2026-09-16.

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