# Transfer files
<a name="transfer-files-and-track"></a>

**Topics**
+ [Send and retrieve files by using an SFTP connector](#send-retrieve-connector-details)

## Send and retrieve files by using an SFTP connector
<a name="send-retrieve-connector-details"></a>

To send and retrieve files by using an SFTP connector, you use the [https://docs.amazonaws.cn/transfer/latest/APIReference/API_StartFileTransfer.html](https://docs.amazonaws.cn/transfer/latest/APIReference/API_StartFileTransfer.html) API operation and specify the following parameters, depending on whether you're *sending files* (outbound transfers) or *receiving files* (inbound transfers). Note that each `StartFileTransfer` request can contain 10 distinct paths. 

**Note**  
 By default, SFTP connectors process one file at a time, transferring files sequentially. You have an option to accelerate transfer performance by having your connectors create concurrent sessions with remote servers that support concurrent sessions from the same user, and process up to 5 files in parallel.   
 To enable concurrent connections for any connector, you can edit the **Maximum conncurent connections** setting when creating or updating a connector. For details, see [Create an SFTP connector with service-managed egress](create-sftp-connector-procedure.md). 
+ **Outbound transfers** 
  + `send-file-paths` contains from one to ten source file paths, for files to transfer to the partner's SFTP server.
  + `remote-directory-path` is the remote path to send a file to on the customer's SFTP server.
+ **Inbound transfers** 
  + `retrieve-file-paths` contains from one to ten remote paths. Each path specifies a location for transferring files from the partner's SFTP server to your Transfer Family server.
  + `local-directory-path` is the Amazon S3 location (bucket and optional prefix) where your files are stored.

To send files, you specify the `send-file-paths` and `remote-directory-path` parameters. You can specify up to 10 files for the `send-file-paths` parameter. The following example command sends the files named `/amzn-s3-demo-source-bucket/file1.txt` and `/amzn-s3-demo-source-bucket/file2.txt`, located in Amazon S3 storage, to the `/tmp` directory on your partner's SFTP server. To use this example command, replace the `amzn-s3-demo-source-bucket` with your own bucket.

```
aws transfer start-file-transfer --send-file-paths /amzn-s3-demo-source-bucket/file1.txt /amzn-s3-demo-source-bucket/file2.txt \
    --remote-directory-path /tmp --connector-id c-1111AAAA2222BBBB3 --region us-east-2
```

To retrieve files, you specify the `retrieve-file-paths` and `local-directory-path` parameters. The following example retrieves the files `/my/remote/file1.txt` and `/my/remote/file2.txt` on the partner's SFTP server, and places it in the Amazon S3 location /amzn-s3-demo-bucket/*prefix*. To use this example command, replace the `user input placeholders` with your own information.

```
aws transfer start-file-transfer --retrieve-file-paths /my/remote/file1.txt  /my/remote/file2.txt \
   --local-directory-path /amzn-s3-demo-bucket/prefix --connector-id c-2222BBBB3333CCCC4 --region us-east-2
```

The previous examples specify absolute paths on the SFTP server. You can also use relative paths: that is, paths that are relative to the SFTP user's home directory. For example, if the SFTP user is `marymajor` and their home directory on the SFTP server is `/users/marymajor/`, the following command sends `/amzn-s3-demo-source-bucket/file1.txt` to `/users/marymajor/test-connectors/file1.txt`

```
aws transfer start-file-transfer --send-file-paths /amzn-s3-demo-source-bucket/file1.txt \
   --remote-directory-path test-connectors --connector-id c-2222BBBB3333CCCC4 --region us-east-2
```