Startup offers free AI code review tool for non-commercial open source projects (blog.macroscope.com)

Macroscope is now free for qualified non-commercial open source projects. The startup says its AI code review suite will be made available at no cost to maintainers who apply, and it's also offering sponsorships for standout projects. The move aims to address two persistent open source pain points: catching correctness bugs that often slip through human review and reducing the time contributors spend explaining changes so maintainers can focus on higher-value review work. Technically, Macroscope auto-generates and updates PR summaries (in descriptions or comments), pinpoints where reviewers should start, and produces ongoing codebase activity summaries and productivity insights for GitHub org members. Its review agent detects bugs, proposes diffs to fix them, and can be chatted with directly in PR comments. In a September 2025 benchmark on 100+ real-world open source bugs, Macroscope reportedly found the most bugs with a modest average of 2.6 comments per PR—far fewer noisy comments than rivals—while also classifying work into projects and surfacing high-level change overviews. Maintainers can apply for free access; non-open-source users get a two-week trial, and the company reserves the right to limit usage based on fair-use criteria.