System76's COSMIC desktop project updated its contribution rules on October 2, 2026, and the change is blunt: pull requests that include any LLM-generated content — source code, comments, or even PR descriptions — will no longer be accepted.
The new policy goes further than simple disclosure. It's an outright ban. Contributors are now required to confirm that nothing in their submission was generated by a large language model before a pull request can be merged.
Why the Ban?
COSMIC lead developer Jeremy Soller of System76 explained the reasoning publicly: the project was being swamped. LLMs have made it trivially easy for first-time contributors to generate plausible-looking code and submit it — but plausible-looking is not the same as correct, aligned with the project's architecture, or planned by the maintainers.
According to Soller, the flood of LLM-generated submissions was "unplanned and rarely accepted," but reviewing them placed a real burden on the small core team. The volume was straining maintainers to the point of unsustainability.
A Pattern Across Open Source
COSMIC isn't the first open source project to encounter this problem, but it may be one of the most prominent to draw a hard line. The project is written in Rust, targets a technically demanding domain — a full Wayland-based desktop environment built from scratch — and has a lean maintainer team. All three factors make low-quality submissions especially costly to process.
Other projects have adopted disclosure requirements or AI-contribution labels. COSMIC's approach is more aggressive: no LLM output, full stop. The policy applies to code, inline comments, and the PR description itself.
One Exception
The ban doesn't extend to the cosmic-flatpak repository, where upstream projects manage their own Flatpak manifests. The COSMIC team reviews those primarily for sandboxing compliance, making the context different enough to warrant separate treatment.
What This Signals
This is a real tension playing out across open source right now. AI tools make contribution easier — but the review cost doesn't disappear just because the code was generated cheaply. If anything, low-effort AI submissions shift cost from the contributor to the maintainer. COSMIC's ban is one data point on how projects with limited bandwidth plan to navigate that tradeoff: drawing a bright line and enforcing it, rather than trying to evaluate AI-generated code case by case.