## Upload a file to a chat folder

`POST /v1/chats/:chatId/files/uploads`

> **This method is rolling out in `im 26.1500.0`.** It is not available on every Bitrix24 account yet. Until the method arrives, the API returns `422 METHOD_NOT_YET_AVAILABLE` with `error.release`.

Uploads one file into the chat folder without posting a message. To publish it, call the [publish route](/docs/chats/files/upload-publish) with `data.file.id` in `uploadIds`.

## Parameters

| Parameter | Type | Required | Description |
|-----------|------|:--------:|-------------|
| `chatId` (path) | number | yes | Chat ID |
| `filename` (body) | string | yes | File name with extension |
| `content` (body) | string | yes | Base64 content, up to 4 MiB after decoding |

Requires the `im` scope and a write-enabled key. The JSON body limit is 40 MiB; large requests may receive `429 LARGE_BODY_BACKEND_BUSY` with `Retry-After`. Other fields and query parameters are rejected with `400 INVALID_PARAMS`. The platform does not retry this call after an unknown outcome.

## Examples

### curl — personal key

```bash
curl -X POST https://vibecode.bitrix24.com/v1/chats/42/files/uploads \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"filename":"a.txt","content":"YWJj"}'
```

### curl — OAuth application

```bash
curl -X POST https://vibecode.bitrix24.com/v1/chats/42/files/uploads \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"filename":"a.txt","content":"YWJj"}'
```

### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/42/files/uploads', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({"filename": "a.txt", "content": "YWJj"}),
})
const { success, data, error } = await res.json()
console.log(success ? data : error)
```

### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/42/files/uploads', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({"filename": "a.txt", "content": "YWJj"}),
})
const { success, data, error } = await res.json()
console.log(success ? data : error)
```

## Response fields

| Field | Type | Description |
|------|-----|---------|
| `success` | boolean | `true` on success |
| `data.file` | object | File in the chat folder; token-bearing URLs are nulled |
| `data.file.id` | number | Uploaded file ID; pass it in `uploadIds` when publishing |
| `data.file.name` | string | File name |
| `data.file.size` | number | File size in bytes |
| `data.chatId` | number | Chat ID |
| `data.dialogId` | string | Dialog ID; no `messageId` |

## Response example

```json
{
  "success": true,
  "data": {
    "file": {
      "id": 7701,
      "name": "a.txt",
      "size": 3
    },
    "chatId": 42,
    "dialogId": "chat42"
  }
}
```

## Error response example

```json
{
  "success": false,
  "error": {
    "code": "INVALID_PARAMS",
    "message": "`content` exceeds the 4 MiB file limit."
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|---------|
| 400 | `INVALID_PARAMS`, `INVALID_CHAT_ID` | Invalid body, chat ID, or unexpected parameters |
| 401 | `TOKEN_MISSING` | No Bitrix24 access tokens |
| 403 | `SCOPE_DENIED`, `WRITE_BLOCKED_READONLY_KEY`, `BITRIX_ACCESS_DENIED` | Missing scope, write permission, or Bitrix24 access |
| 413 | `PAYLOAD_TOO_LARGE` | JSON body exceeds 40 MiB; reduce the request |
| 422 | `METHOD_NOT_YET_AVAILABLE`, `BITRIX_ERROR` | Method has not reached Bitrix24, or the Bitrix24 refused the file |
| 429 | `LARGE_BODY_BACKEND_BUSY`, `QUEUE_TIMEOUT` | Retry according to `Retry-After` |

Any `errors[]` item is a refusal even when the Bitrix24 responds HTTP 200. Named refusals can become `400 INVALID_PARAMS` or `403 BITRIX_ACCESS_DENIED`; generic `422 BITRIX_ERROR` includes `error.b24Code` only when a code is recognized. The platform does not retry an upload after an unknown outcome.

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

## See also

- [Check existence](/docs/chats/files/upload-status)
- [Discard file](/docs/chats/files/upload-discard)
- [Publish files](/docs/chats/files/upload-publish)
- [Chat files](/docs/chats/files)