> For the complete documentation index, see [llms.txt](https://docs.duplicati.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.duplicati.com/backup-destinations/provider-specific-destinations/tencent-cos-destination.md).
# Tencent COS Destination
This page describes the Tencent COS storage destination
{% hint style="info" %}
This destination is marked as untested, as the Duplicati team does not have an account to test it with. It is hidden from the destination list in the user interface, see [deprecated and untested destinations](/backup-destinations/destination-overview.md#deprecated-and-untested-destinations).
{% endhint %}
Duplicati supports storing files on [Tencent Cloud Object Storage (COS)](https://www.tencentcloud.com/products/cos) which is a large-scale object storage, similar to S3. In Tencent COS you store "objects" (similar to files) in "buckets" which define various properties shared between the objects. If you use a `/` in the object prefix, they can be displayed as virtual folders when listing them.
## User interface
To configure the Tencent COS destination you must supply: bucket, path, app id, region, secret id, and secret key.
## URL format for Commandline
To use COS, you can use the following URL format:
```
cos://
?cos-bucket=
&cos-region=
&cos-app-id=
&cos-secret-id=
&cos-secret-key=
```
The bucket name is user-chosen, and the region must match the [bucket region](https://www.tencentcloud.com/document/product/436/6224). The remaining values can be obtained from the Cloud Console.
Note that the bucket must be created from within the Cloud Console prior to use.
## Storage class
The objects uploaded can be in different [storage classes](https://www.tencentcloud.com/document/product/436/30925), which can be set with `--cos-storage-class`.
**NOTE:** The `ARCHIVE` and `DEEP_ARCHIVE` storage does not work well with Duplicati. Because Duplicati really likes to verify that things are working as expected you need to disable these checks. You also need to disable cleanup of data after deleting versions. Restores are tricky, because you need to manually restore data to the standard storage class before Duplicati can access it.
---
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