I've reviewed all the changed files and surrounding context. Let me now analyze the changes:

Changes summary:

1. ai-api.ts: Changes RPC opt-in logic from aiBindingExperimental || options?.beta === true to options?.beta ?? aiBindingExperimental — allows explicit opt-out via {beta: false}
2. aig-api.ts: Adds signal?: AbortSignal to run() options, passes it through to fetch()
3. Tests: Two new test cases for AbortSignal (pre-aborted and in-flight abort)
4. Type definitions: Updated across all snapshot files

Analysis:

• The options?.beta ?? aiBindingExperimental logic is correct. The nullish coalescing operator (??) falls through to aiBindingExperimental only when options?.beta is undefined or null, not when it's false. This enables the documented opt-out behavior. The comment explains the rationale clearly.

• The AbortSignal pass-through in aig-api.ts is straightforward — it just forwards signal from options to fetch(). The conditional assignment (if (options?.signal)) is fine since undefined is the default for signal in RequestInit anyway.

• The test coverage is good: tests both pre-aborted signal and in-flight abort via AbortController.

• Type definitions are consistent across all four snapshot files and aig.d.ts.

• No backward compatibility concerns: signal is a new optional field, and the beta: false opt-out is additive behavior.

• No security concerns: the signal just propagates standard abort semantics to the underlying fetch.

• No compat flag needed: this is purely additive (new optional parameter, new opt-out capability).

I don't see any actionable issues with this PR.

LGTM

github run

By the way, our own ai-gateway-provider package (vercel AI SDK plugin) is already passing this option along when the application passes an AbortSignal to AI SDK... because I asked @threepointone to implement that before I realized the runtime itself didn't support it, and he dutifully did as I asked.

As a result, when the binding started using RPC (for "experimental" users) last week, it actually broke anyone using ai-gateway-provider, AbortSignal, and the "experimental" flag together. Which may very well have been only me, but it was a spontaneous breakage in prod, which confused me.