## Create comment

`POST /v1/tasks/:taskId/comments`

Adds a comment to a task. On the new task card the message is posted to the chat; on the old one it lands in the comments block inside the card itself.

## Parameters

| Parameter | Type | Required | Description |
|----------|-----|:-----:|---------|
| `taskId` (path) | number | yes | Task ID |

## Request fields (body)

| Field | Type | Required | Description |
|------|-----|:-----:|---------|
| `message` | string | ★ | Comment text, up to 65,535 characters. Supports BB-code (`[USER=ID]Name[/USER]`, `[B]...[/B]`, `[QUOTE]...[/QUOTE]`) |

## Examples

### curl — personal key

```bash
curl -X POST "https://vibecode.bitrix24.com/v1/tasks/289/comments" \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Added a draft of the report — please take a look."
  }'
```

### curl — OAuth app

```bash
curl -X POST "https://vibecode.bitrix24.com/v1/tasks/289/comments" \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Added a draft of the report — please take a look."
  }'
```

### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/tasks/289/comments', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    message: 'Added a draft of the report — please take a look.',
  }),
})

const { success, data } = await res.json()
console.log('New comment ID:', data.id)
```

### JavaScript — OAuth app

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/tasks/289/comments', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    message: 'Added a draft of the report — please take a look.',
  }),
})

const { success, data } = await res.json()
```

## Response fields

| Field | Type | Description |
|------|-----|---------|
| `success` | boolean | Always `true` on success |
| `data.id` | number \| null | New comment identifier. On the new card the chat-message id is returned; in a rare case it may be `null` — see "Known specifics" |

## Response example

HTTP 201 Created:

```json
{
  "success": true,
  "data": {
    "id": 36559
  }
}
```

## Error response example

400 — empty or missing `message`:

```json
{
  "success": false,
  "error": {
    "code": "INVALID_PARAMS",
    "message": "`message` is required and must be a string"
  }
}
```

404 — the task doesn't exist or isn't accessible:

```json
{
  "success": false,
  "error": {
    "code": "TASK_NOT_FOUND",
    "message": "Bitrix24 did not create the comment (returned false). Task 99999999 may not exist or may not be accessible."
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|---------|
| 400 | `INVALID_PARAMS` | `taskId` is not a positive integer |
| 400 | `INVALID_PARAMS` | The `message` field is missing or is not a string |
| 400 | `INVALID_PARAMS` | `message` exceeds the length limit |
| 403 | `SCOPE_DENIED` | The API key does not have the `task` scope |
| 401 | `TOKEN_MISSING` | The API key has no configured tokens |
| 404 | `TASK_NOT_FOUND` | Task `taskId` doesn't exist or isn't accessible to the key — Bitrix24 didn't create the comment |

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

## Known specifics

**`data.id` is occasionally `null` on success (`success: true`).** On the new task card the comment goes to chat (`tasks.task.chat.message.send`), and the id is recovered by a separate search over recent chat messages. If recovering the id fails (the message wasn't found in the search window), the comment **was already created**, but the response returns `id: null` — this is not an error, and retrying the request will create a duplicate. If Bitrix24 didn't create the comment at all (the task doesn't exist or isn't accessible), that's a different case — the API returns `404 TASK_NOT_FOUND` instead of `201` with `id: null`.

## See also

- [List comments](./list.md) — find the added comment
- [Get comment](./get.md) — read by `id`
- [Batch operations](./comments-batch.md) — add several comments in one request
- [Tasks](/docs/entities/tasks) — parent entity
- [Limits and optimization](/docs/optimization) — rate limits