## Message blocks

A constructor message consists of blocks: text, a heading, an image and other elements that Bitrix24 assembles into one message. These calls add, replace and delete the blocks of such a message. The v2 messenger methods: `im.v2.Chat.Message.Block.Element.append`, `im.v2.Chat.Message.Block.Element.update` and `im.v2.Chat.Message.Block.Element.delete`.

## Add a block

`POST /v1/chats/messages/:messageId/blocks`

Adds a block to the end of the message.

### Parameters

| Parameter | Type | Required | Default | Description |
|----------|-----|:-----:|-----------|---------|
| `messageId` (path) | number | yes | — | ID of the constructor message, a positive integer |
| `element` (body) | object | yes | — | A block in the Bitrix24 constructor format: `type` and the fields of that type, for example `{ "type": "text", "text": "Build passed" }` |

Other body fields and query parameters are rejected with `400 INVALID_PARAMS`.

### Examples

#### curl — personal key

```bash
curl -X POST "https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks" \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "element": { "type": "text", "text": "Build passed" } }'
```

#### curl — OAuth application

```bash
curl -X POST "https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks" \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{ "element": { "type": "text", "text": "Build passed" } }'
```

#### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ element: { type: 'text', text: 'Build passed' } }),
})

const { data } = await res.json()
console.log('Block added:', data.result)
```

#### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ element: { type: 'text', text: 'Build passed' } }),
})

const { data } = await res.json()
console.log('Block added:', data.result)
```

## Replace a block

`PATCH /v1/chats/messages/:messageId/blocks/:blockId`

Replaces the block entirely. The block ID is kept.

### Parameters

| Parameter | Type | Required | Default | Description |
|----------|-----|:-----:|-----------|---------|
| `messageId` (path) | number | yes | — | ID of the constructor message, a positive integer |
| `blockId` (path) | string | yes | — | Block ID — `block.elements[].id` of the message |
| `element` (body) | object | yes | — | The new block in the constructor format |

Other body fields and query parameters are rejected with `400 INVALID_PARAMS`.

### Examples

#### curl — personal key

```bash
curl -X PATCH "https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5" \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "element": { "type": "text", "text": "Build failed" } }'
```

#### curl — OAuth application

```bash
curl -X PATCH "https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5" \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{ "element": { "type": "text", "text": "Build failed" } }'
```

#### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5', {
  method: 'PATCH',
  headers: {
    'X-Api-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ element: { type: 'text', text: 'Build failed' } }),
})

const { data } = await res.json()
console.log('Block replaced:', data.result)
```

#### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5', {
  method: 'PATCH',
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ element: { type: 'text', text: 'Build failed' } }),
})

const { data } = await res.json()
console.log('Block replaced:', data.result)
```

## Delete a block

`DELETE /v1/chats/messages/:messageId/blocks/:blockId`

### Parameters

| Parameter | Type | Required | Default | Description |
|----------|-----|:-----:|-----------|---------|
| `messageId` (path) | number | yes | — | ID of the constructor message, a positive integer |
| `blockId` (path) | string | yes | — | Block ID |

No body is needed. Query parameters and body fields are rejected with `400 INVALID_PARAMS`.

### Examples

#### curl — personal key

```bash
curl -X DELETE "https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5" \
  -H "X-Api-Key: YOUR_API_KEY"
```

#### curl — OAuth application

```bash
curl -X DELETE "https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5" \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN"
```

#### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5', {
  method: 'DELETE',
  headers: { 'X-Api-Key': 'YOUR_API_KEY' },
})

const { data } = await res.json()
console.log('Block deleted:', data.result)
```

#### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/1001/blocks/650a1b2c3d4e5', {
  method: 'DELETE',
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
  },
})

const { data } = await res.json()
console.log('Block deleted:', data.result)
```

## Response fields

| Field | Type | Description |
|------|-----|---------|
| `success` | boolean | Always `true` on success |
| `data.result` | boolean | `true` — the block was added, replaced or deleted |

## Response example

```json
{
  "success": true,
  "data": { "result": true }
}
```

## Error response example

422 — the message has no blocks:

```json
{
  "success": false,
  "error": {
    "code": "BITRIX_ERROR",
    "message": "BLOCK_NOT_FOUND",
    "b24Code": "BLOCK_NOT_FOUND"
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|---------|
| 400 | `INVALID_PARAMS` | `messageId` is not a positive integer; `element` is missing or not an object; an extra body field or a query parameter. Checked before any call to Bitrix24 |
| 404 | `ENTITY_NOT_FOUND` | Bitrix24 returned "not found"; the portal code is in `error.b24Code` |
| 422 | `BITRIX_ERROR` | Bitrix24 returned an error; the portal code is in `error.b24Code`. `BLOCK_NOT_FOUND` — the message has no blocks; `ELEMENT_NOT_FOUND` — there is no block with this ID; `WRONG_ELEMENT_TYPE`, `EMPTY_TEXT_FIELD` — the block is malformed; `BLOCK_LENGTH_EXCEEDED` — the message blocks exceed the limit; `MESSAGE_ACCESS_DENIED` — the message cannot be edited |
| 403 | `SCOPE_DENIED` | The API key does not have the `im` scope |
| 403 | `WRITE_BLOCKED_READONLY_KEY` | The key is read-only — see [access rights](/docs/access-rights) |
| 401 | `TOKEN_MISSING` | The API key has no Bitrix24 tokens configured |

The full list of common API errors — [Errors](/docs/errors).

## Known specifics

**Constructor messages only.** Blocks exist only on a message sent with blocks. A plain message has none, and Bitrix24 returns `BLOCK_NOT_FOUND` — a plain message cannot be turned into a constructor message.

**The response does not include the new block's ID.** Adding a block returns `{ "result": true }`. Read block IDs from `block.elements[].id` of the message — for example, with [messages around a message](/docs/chats/messages/context).

**Bitrix24 checks the block shape.** The platform only checks that `element` is an object and passes it as is. Block types and their fields are defined by the Bitrix24 constructor.

**Whoever can edit the message can edit its blocks.** Usually that is the author; Bitrix24 refuses everyone else with `MESSAGE_ACCESS_DENIED`.

## See also

- [Edit a message](/docs/chats/messages/update)
- [Messages around a message](/docs/chats/messages/context)