---
title: 为草稿上传附件
description: 为邮件草稿创建上传会话并上传二进制附件。
sidebar_label: 为草稿上传附件
sidebar_position: 3
---

# 为草稿上传附件

附件需要绑定到已存在的草稿。先创建草稿，再为每个附件创建独立上传会话并上传文件流。

## 调用顺序

1. 创建草稿，取得 `message.id`。
2. 调用[创建附件上传会话](/api/alimailpb-alimail-mailagent-open-mail-service-create-attachment-upload-session)。
3. 使用响应中的上传地址或会话标识调用[上传文件流](/api/alimailpb-stream-stream-service-do-upload)。
4. 完成所有附件后发送草稿，或保留在草稿箱中供人工确认。

## Python 示例

```python runtimeApiEndpoint
from pathlib import Path
import requests

API_BASE = "https://alimail-cn.aliyuncs.com"


def upload_attachment(
    access_token: str,
    mailbox: str,
    draft_id: str,
    file_path: Path,
) -> None:
    headers = {
        "Authorization": f"Bearer {access_token}",
        "Content-Type": "application/json",
    }
    session = requests.post(
        f"{API_BASE}/v2/users/{mailbox}/messages/{draft_id}/attachments/createUploadSession",
        headers=headers,
        json={"attachment": {"name": file_path.name, "isInline": False}},
        timeout=15,
    )
    session.raise_for_status()
    upload_url = session.json()["uploadUrl"]

    with file_path.open("rb") as stream:
        uploaded = requests.post(
            upload_url,
            headers={"Authorization": f"Bearer {access_token}"},
            data=stream,
            timeout=60,
        )
    uploaded.raise_for_status()
```

上传前校验文件大小、扩展名和内容类型。不要把上传地址写入日志，它可能包含短期有效的会话信息。

参考：[原始示例](https://help.aliyun.com/zh/document_detail/2856471.html)。