How to complete the challenge `GET /api/todos (200) ? filter id less than`

By Alan RichardsonPublished 2026-07-31

How to issue a GET request on a top level entity endpoint and filter todos by ids less than a supplied value.

GET /api/todos (200) ? filter id less than

Issue a GET request on the /api/todos end point with an id filter to return todos with an id less than a supplied value, requesting the response in JSON format.

id<6 means return todos where the id is less than 6
most tools and browsers will encode the < symbol for you when sending the request
the response should contain at least one todo
the response should be a subset of the current todos, not the full list
every returned todo should have an id less than the threshold
the returned todo list should be JSON, so send Accept: application/json if the response is not 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 an id less-than filter:
- https://apichallenges.com/api/todos?id<6
The response status code should be 200 because the request is accepted
Check that every returned todo has an id less than 6

Try it now

If you need to check which todo ids are available, use GET /api/todos. See the solution.

GET /api/todos to see the available todo ids

The sample below uses id<6; edit the threshold if your current data needs a different subset.

GET /api/todos?id<6 to return todos with ids less than 6

Example Request

> GET /api/todos?id<6 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": 2, "title": "lower id todo", "doneStatus": false, "description": "" }
  ]
}

Lessons Learned

id< filtering checks the lower side of numeric range handling.
The boundary value itself should be excluded from a strict less-than result.
Empty results can still be valid when no resource satisfies the comparison.

Suggested Experiments

Use the smallest known todo id as the boundary and confirm the response becomes empty or very small.
Pair id< with a GET /api/todos baseline so you can explain every returned id.

Experiment with this endpoint

How to complete the challenge GET /api/todos (200) ? filter id less than