GitHub API's `updated_at` Sort Inconsistency: Impact on Engineering Project Management Software

A recent discussion in the GitHub Community has brought to light a significant inconsistency in the GitHub Pull Request API, specifically concerning the sort=updated parameter. Developers relying on accurate, time-based sorting for their integrations, particularly those powering engineering project management software, are encountering non-monotonic results, leading to critical data synchronization issues.

The Core Inconsistency: updated_at vs. Sort Key

The original poster, zakhij, meticulously detailed how the GET /repos/{owner}/{repo}/pulls?state=all&sort=updated&direction=desc endpoint fails to sort pull requests strictly by their updated_at field, as returned in the response body. Instead, their investigation suggests the API sorts by the most recent entry in the more limited /issues/{n}/events endpoint, which does not capture all activities that update the updated_at timestamp.

This divergence means that activities like comments or reviews, which update a PR's updated_at field (tracked by the richer /issues/{n}/timeline), do not necessarily affect its sort position. The result is a seemingly random ordering where a PR with a very recent updated_at might appear far from its expected position, surrounded by much older entries.

Zakhij provided a clear example, demonstrating the issue with a paginated curl request:

for page in $(seq 1 22); do
    echo "===== page $page ====="
    curl -sS \
        -H "Authorization: Bearer $TOKEN" \
        -H "Accept: application/vnd.github.v3+json" \
        -H "X-GitHub-Api-Version: 2022-11-28" \
        "https://api.github.com/repos/$REPO/pulls?state=all&sort=updated&direction=desc&per_page=100&page=$page" \
        | jq -r '.[] | "\(.number)	\(.updated_at)"'
done

This script revealed instances where PRs with updated_at timestamps from 2026 were interspersed with those from 2023 or 2024, defying the expected descending sort order. A "smoking gun" analysis of PR #68 further solidified the theory: its sort position matched an event from September 2025, not its visible updated_at of November 2025, which was updated by a comment.

Impact on API Consumers and Engineering Project Management Software

For developers building integrations, this inconsistency is more than a minor annoyance; it's a critical flaw. Any client using sort=updated for:

• Binary-search counting
• Cursor-by-timestamp pagination
• Windowed or incremental data synchronization

...will silently overcount, undercount, or skip records. This directly compromises the data integrity and reliability of applications, especially sophisticated engineering project management software that depends on accurately tracking and syncing GitHub data to provide real-time insights and metrics.

Community Confirmation and Practical Workarounds

Another community member, SarthkDeshmukh, confirmed experiencing the exact same frustration. They elaborated on the underlying mechanisms:

• The sort=updated parameter reflects the last time any metadata changed on the PR (labels, assignees, review requests), not just code pushes or comments.
• GitHub's REST API uses internal cursor-based pagination, meaning results across pages aren't always globally sorted, but rather sorted within the dataset already filtered by GitHub.

Given this known inconsistency, SarthkDeshmukh offered several practical workarounds for developers:

• Leverage the GraphQL API: The GraphQL endpoint offers more reliable sorting with pullRequests(orderBy: {field: UPDATED_AT, direction: DESC}), providing genuinely sorted results.
• Client-Side Sorting: For smaller datasets, fetching all PRs and sorting them client-side can ensure accuracy.
• Filter First with REST: Reduce the dataset by filtering by state (e.g., state=open) before attempting to sort, which may yield more consistent results within that smaller scope.

The key takeaway for developers is a crucial lesson in API integration: never fully trust API-side sorting for anything where order is business-critical. Always validate or re-sort on your side. While these workarounds help mitigate the immediate impact, the community's desire remains for GitHub to align the sort=updated behavior with the visible updated_at field, ensuring consistency for all API consumers, especially those building robust engineering project management software and other developer tools.