doc: create ai-guidelines and include to CONTRIBUTING

CONTRIBUTING.md

@@ -20,6 +20,7 @@ works.
 * [Issues](#issues)
 * [Pull Requests](#pull-requests)
 * [Automation and bots](#automation-and-bots)
+* [AI Use Policy and Guidelines](#ai-use-policy-and-guidelines)
 * [Developer's Certificate of Origin 1.1](#developers-certificate-of-origin-11)
 
 ## [Code of Conduct](./doc/contributing/code-of-conduct.md)
@@ -60,6 +61,15 @@ by an automation that was not authorized by Node.js collaborators are
 subject to immediate moderation enforcement on the automation and owner
 without notice.
 
+## [AI Use Policy and Guidelines](./doc/contributing/ai-guidelines.md)
+
+Node.js requires contributors to understand and take full responsibility for
+every change they propose. Pull requests containing AI-generated code the
+contributor has not personally understood, tested, and verified will likely be closed
+without review.
+
+See [details on our AI use policy and guidelines](./doc/contributing/ai-guidelines.md).
+
 ## Developer's Certificate of Origin 1.1
 
 ```text

doc/contributing/ai-guidelines.md

@@ -0,0 +1,95 @@
+# AI use policy and guidelines
+
+* [Core principle](#core-principle)
+* [Using AI for code contributions](#using-ai-for-code-contributions)
+* [Using AI for communication](#using-ai-for-communication)
+
+This document aligns with the [OpenJS Foundation AI Coding Assistants Policy][].
+
+## Core principle
+
+Node.js expects contributions to come from _people_. Contributors are free
+to use whatever tools they choose, including AI assistants, but such tools
+never replace the contributor's own understanding and responsibility.
+
+Node.js requires contributors to understand and take full responsibility for
+every change they propose. The answer to "Why is X an improvement?" can
+never be "I'm not sure. The AI did it."
+
+If AI tools assisted in generating a contribution, acknowledge that honestly
+in the commit metadata using an `Assisted-by:` trailer. This applies
+regardless of how much of the work was AI-generated — the contributor
+remains the sole author and bears full responsibility for every line.
+If the disclosure involves trademarks or commercial brands, it's recommended to
+anonymize it in the commit message or only mention it in the PR description,
+but not in the commit message, unless the context would not have made sense
+without mentioning the specific brand/trademark.
+
+Pull requests that contain AI-generated code the contributor has not
+personally understood, tested, and verified waste collaborator time and
+will be subject to closure without additional review. Contributors who
+repeatedly submit such changes, show no understanding of the project or
+its processes, or are dishonest about the use of automated assistance
+may be blocked from further contributions.
+
+Pull requests must not be opened by automated tooling not specifically
+approved in advance by the project.
+
+## Using AI for code contributions
+
+Contributors may use AI tools to assist with contributions, but such tools
+never replace human judgment.
+
+When using AI as a coding assistant:
+
+* **Understand the codebase first.** Do not skip familiarizing yourself with
+  the relevant subsystem. LLMs frequently produce inaccurate descriptions of
+  Node.js internals — always verify against the actual source. When using an AI
+  tool, ask it to cite the exact source it’s relying on, and then
+  match the claim against that resource to verify if it holds up in the current
+  code.
+
+* **Own every line you submit.** You are responsible for all code in your
+  pull request, regardless of how it was generated. This includes ensuring
+  that AI-generated or AI-assisted contributions satisfy the project's
+  [Developer's Certificate of Origin][] and licensing requirements. Be
+  prepared to explain any change in detail during review.
+
+* **Keep logical commits.** Structure commits coherently even when an LLM
+  generates multiple changes at once. Follow the existing
+  [commit message guidelines][].
+
+* **Test thoroughly.** AI-generated code must pass the full test suite and
+  any manually written tests relevant to the change. Existing tests should not
+  be removed or modified without human verification. Do not rely on the LLM
+  to assess correctness. It is crucial to manually verify the correctness of
+  tests against the expected behavior of the feature being tested,
+  independently of the feature's implementation.
+
+* **Do not disappear.** If you open a PR, follow it through. Respond to
+  feedback and iterate until the work lands or is explicitly closed. If you
+  can no longer pursue it, close the PR. Stalled PRs block progress.
+
+* **Do not use AI to claim "good first issue" tasks.** These issues exist to
+  help new contributors learn the codebase and processes hands-on.
+
+* **Edit generated comments critically.** LLM-produced comments are often
+  verbose or inaccurate. Remove comments that simply restate what the code
+  does; add comments only where the logic is non-obvious.
+
+## Using AI for communication
+
+Node.js values concise, precise communication that respects collaborator and contributor time.
+
+* **Do not post messages generated entirely by AI** in pull requests, issues, or the
+  project's communication channels.
+* **Verify accuracy** of any LLM-generated content before including it in a
+  PR description or comment.
+* **Link to primary sources** — code, documentation, specifications — rather
+  than quoting LLM answers or linking to LLM chats.
+* Grammar and spell-check tools are acceptable when they improve clarity and
+  conciseness.
+
+[Developer's Certificate of Origin]: ../../CONTRIBUTING.md#developers-certificate-of-origin-11
+[OpenJS Foundation AI Coding Assistants Policy]: https://openjsf.cdn.prismic.io/openjsf/aca4d5GXnQHGZDiZ_OpenJS_AI_Coding_Assistants_Policy.pdf
+[commit message guidelines]: ./pull-requests.md#commit-message-guidelines