Method	Path	Auth	Request Body	Description
GET	/health	No	—	Simple health-check.
GET	/credits/:id	Yes	—	Retrieve the number of virtual credits the user with id has. Returns { "id": <int>, "credits": <int> }.
PATCH	/credits/add/:id	Yes	{ "amount": <int> }	Add virtual credits to user with id. Returns { "message":"Credits added", "id":<int>, "new_credits":<int> } OR {error: [error message]}.
PATCH	/credits/deduct/:id	Yes	{ "amount": <int> }	Deduct virtual credits from the user's account. Returns { "message":"Credits deducted", "id":<int>, "new_credits":<int> } OR {error: [error message]}.