How to complete the challenge PUT /api/todos/{id} no title (422)

By Alan Richardson · Published 2026-07-20

Issue a PUT request to an existing todo and omit the mandatory title field.

The response should be 422 Unprocessable Content because the request body is valid JSON, but the replacement todo fails validation.

Look for the validation message containing:

title : field is mandatory

Try it now

If you don't know what todos are available then you can check by GET /api/todos. See the solution.

GET /api/todos to see what todos are available now

If you have already deleted all todos, create one using POST /api/todos. See the solution.

POST /api/todos to create a todo item for this challenge

PUT /api/todos/{id} without a title to trigger 422

Lessons Learned

• title is mandatory for this PUT update, even when the resource id is valid.
• Required-field validation happens after the API has identified the target resource.
• A missing required field is different from an empty or too-long value.

Suggested Experiments

• Add title back without changing any other field and confirm the request becomes valid.
• Send title as an empty string and compare that error with the missing-title response.

Experiment with this endpoint