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+# RFC 239: Policy on LLM assistance in contributions
+
+## Summary
+
+Introduce guidelines for acceptable use of large-language models when
+contributing to web-platform-tests.
+
+## Background
+
+[#202 Set policy for LLM-generated
+tests](https://github.com/web-platform-tests/rfcs/issues/202) includes evidence
+for public interest in a formal policy for LLM usage in authoring contributions
+to WPT.
+
+The Chrome team is exploring applications of LLMs for detecting coverage gaps
+and for filling those gaps with generated code. ([Project
+repository](https://github.com/GoogleChromeLabs/wpt-gen), [April 2026
+presentation](https://www.youtube.com/watch?v=9r0PBbJFLoM))
+
+A few examples of policies on LLM use in FOSS contributions:
+
+- permissive
+  - [ghostty/AI_POLICY.md at main · ghostty-org/ghostty](https://github.com/ghostty-org/ghostty/blob/main/AI_POLICY.md)
+  - [Policy about LLM generated code from PRs · Issue #28335 · opencv/opencv](https://github.com/opencv/opencv/issues/28335)
+  - [CONTRIBUTING.md: Guidelines relevant to AI-assisted contributions by gasche · Pull Request #14052 · ocaml/ocaml](https://github.com/ocaml/ocaml/pull/14052)
+  - [LLVM AI Tool Use Policy — LLVM 23.0.0git documentation](https://llvm.org/docs/AIToolPolicy.html)
+  - [Chromium AI Coding Policy](https://chromium.googlesource.com/chromium/src/+/4f44016dfbd4fcd890694c00d7f9ec6dcefe4955/agents/ai_policy.md)
+  - [Firefox AI Coding Policy](https://github.com/mozilla-firefox/firefox/blob/1f7030c8de8f2b349c7d91d7b5a3253c109a1cc1/docs/contributing/ai-coding.md)
+- prohibitive
+  - [Code of Conduct ⚡ Zig Programming Language](https://ziglang.org/code-of-conduct/#strict-no-llm-no-ai-policy)
+  - [Getting Started - The Servo Book](https://book.servo.org/contributing/getting-started.html#ai-contributions)
+
+## Details
+
+The following text describes the policy in full and will be maintained in a
+dedicated document within WPT's `docs/writing-tests/` directory (which will be
+referenced both from the project's `README.md` file and the
+`docs/writing-tests/index.md` file):
+
+> ### Guidelines for acceptable LLM use
+>
+> The use of large language models (LLMs) as tools to help author commits to
+> this repository is allowed with the stipulations described below.
+> Contributors who repeatedly fail to adhere to these guidelines may be banned
+> from contributing to this project.
+>
+> #### Disclosure
+>
+> If LLMs are used as a significant input to a commit, authors are encouraged
+> to include details about how they were used as part of the commit message in
+> order to help review and future understanding of the code.
+>
+> Human-authored code discourse (e.g. issue descriptions, pull request
+> descriptions, and responses to discussion threads) should not include
+> LLM-generated content in the main text; any such content must be clearly
+> labelled and placed inside a `<details>` element.
+>
+> #### Attribution
+>
+> All commits must be attributed to the human who is taking responsibility for
+> them, regardless of LLM use.
+>
+> #### Understanding
+>
+> Every pull request must be initiated by one human. That person must author
+> the pull request description, understand every change proposed, and be
+> prepared to engage in technical discussion regarding those changes.
+
+## Risks
+
+### Discouraging volunteers
+
+All but the most permissive policy is effectively another hurdle to
+contributing to the project. Friction in the contribution process could deter
+people who might otherwise volunteer their time to help improve the project.
+
+In some sense, adding friction is the goal of this policy. New technology has
+removed barriers which previously restricted unqualified individuals from
+participation. Rather than introducing more restrictions on good-faith actors,
+an ideal policy will buttress eroded structural barriers with more intentional
+social ones.
+
+### Encouraging low-value contributions
+
+All but the most restrictive policy could be interpreted as an invitation to
+take shortcuts which undermine the quality of contributions. Any permissive
+policy might be taken as encouragement to rely on fallible tools (LLMs are
+particularly susceptible to certain kinds of test-writing errors, such as
+over-fitting and fabrication).
+
+However, it will not be possible to strictly enforce any policy. It inevitably
+falls on contributors to follow rules and for administrators to police
+transgressions. Respect in public works projects is never guaranteed; policies
+exist only to make expectations clear (this is the same dynamic that guides the
+design and enforcement of codes of conduct).