> For the complete documentation index, see [llms.txt](https://docs.apica.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apica.io/platform-docs/test-data-orchestrator-tdo/user-documentation/api-guide/coverage-set-apis/lock-coverage-set.md).
# Lock Coverage Set
This call is sent to lock a coverage set in TDO – this will prevent any other user (within the UI or from automated API calls) from making changes to the coverage set or business rules while you are working within that coverage set. It is sent as a ‘PATCH’.
Note that the header is slightly different (it includes the command ‘lock’ in addition to the coverage set ID.
Lock coverage set call
The body of this call remains the same as the ‘get details’ API.
```
{
"context": {
"user": "mbj_test",
"password": "xxxx",
"project": {
"name": "imp_payments_demo",
"version": "1.0"
}
}
}
```
The return message contains all of the details. Highlighted below is the section of the details around the lock that was placed.
Lock coverage set return message - successfu;
In TDO, the lock can be seen on the main coverage set page; the ID of the user who placed the lock is visible. By hovering the cursor to the right of that ID, you can see the lock icon is also visible.
Coverage set lock shown in TDO
If you try to place a lock, and the coverage set is already locked by a different user, you will get the return message below, including the ID of the user who has the lock in place.