The Person, Not the Cards

In December 2025, Anthropic acquired Bun , the JavaScript runtime written in Zig. In April 2026, the Bun team announced a 4× compile-time improvement on their fork of the Zig compiler — "parallel semantic analysis and multiple codegen units to the llvm backend" , in their phrasing. They also announced they would not be upstreaming the work, "as Zig has a strict ban on LLM-authored contributions." The framing landed badly with Zig observers, for two reasons. The first was that the framing made Zig's contribution policy the obstacle. The second, pointed out shortly afterwards by a Zig core contributor in the Ziggit thread, was that the patch had separate engineering reasons it would not have been merged regardless: "Parallel semantic analysis has been an explicitly planned feature of the Zig compiler for a long time" , with "implications not only for the compiler implementation, but for the Zig language itself" . The AI-ban explanation was, on a closer read, a tidy way of declining to litigate the engineering disagreement in public. Both readings are useful. They are also both downstream of the actual rationale, which is one of the most carefully argued OSS-governance documents to appear in 2026. What the policy actually says The relevant clauses, in the Zig code of conduct under the section heading Strict No LLM / No AI Policy , are three: No LLMs for issues. No LLMs for pull requests. No LLMs for comments on the bug tracker, including translation. English is encouraged, but not required. You are welcome to post in your native language and rely on others to have their own translation tools of choice to interpret your words. The translation clause is the surprising one. It is also the one that disambiguates the policy from a code-quality rule. A blanket ban on LLM-mediated communication, including translation, is not a heuristic about whether agentic tools produce good code. It is a stance about what the project's communication channels are for . Contributor poker Lor