How to complete the challenge `GET /api/todos (200) ? _sortBy multiple`

By Alan RichardsonPublished 2026-07-30

How to issue a GET request on a top level entity endpoint and sort the returned todos by more than one field.

GET /api/todos (200) ? _sortBy multiple

Issue a GET request on the /api/todos end point with a query parameter to sort todos by multiple fields, requesting the response in JSON format.

_sortBy is the URL parameter used to sort collection results
separate multiple sort fields with commas
a plain field name sorts ascending
prefix a field with - to sort descending
for example, _sortBy=doneStatus,-id sorts by doneStatus ascending, then by id descending within each done status
add header Accept: application/json if not present so the filtered and sorted todo collection is returned as JSON

Basic Instructions

Issue a GET request to end point "/api/todos"
- https://apichallenges.com/api/todos
The request should have an X-CHALLENGER header to track challenge completion
The request should have an Accept: application/json header so the API returns todos in JSON format
Add _sortBy=doneStatus,-id as a URL parameter:
- https://apichallenges.com/api/todos?_sortBy=doneStatus,-id
The response status code should be 200 because the request is accepted
Check that todos are grouped by doneStatus, and within each group the ids are descending

Try it now

GET /api/todos?_sortBy=doneStatus,-id to sort todos by multiple fields

Example Request

> GET /api/todos?_sortBy=doneStatus,-id HTTP/1.1
> Host: apichallenges.com
> User-Agent: rest-client
> X-CHALLENGER: x-challenger-guid
> Accept: application/json

Example Response

< HTTP/1.1 200 OK
< Connection: close
< Content-Type: application/json
< X-Challenger: x-challenger-guid

Returned body:

{
  "todos": [
    {
      "id": 8,
      "title": "not done with higher id",
      "doneStatus": false,
      "description": ""
    },
    {
      "id": 3,
      "title": "not done with lower id",
      "doneStatus": false,
      "description": ""
    },
    {
      "id": 9,
      "title": "done with higher id",
      "doneStatus": true,
      "description": ""
    }
  ]
}

Lessons Learned

Multiple _sortBy fields define tie-breaking when the first field has duplicate values.
Multi-sort tests need data with shared primary values, otherwise the secondary sort is invisible.
Comma-separated sort criteria should be parsed in the order supplied.

Suggested Experiments

Create several todos with the same doneStatus but different title values and sort by doneStatus,+title.
Reverse only the secondary sort field and check whether records inside each primary group change order.

Experiment with this endpoint

How to complete the challenge GET /api/todos (200) ? _sortBy multiple