slug: fix-off-by-one
title: "Fix off-by-one error in pagination"
description: |
  The pagination helper in utils/pagination.py has an off-by-one error.
  When requesting page 2 with page_size=10, it returns items 11-20 instead of 10-19.
  Fix the bug so all pagination tests pass.
repo:
  url: https://github.com/example/demo-api.git
  ref: bug-branch-001
success:
  command: "pytest tests/test_pagination.py -x"
limits:
  time_seconds: 300
  max_tokens: 200000
difficulty: easy