cursor-sdk auth.md: non-null assertion described as a runtime missing-variable check #473

Observed at commit 2eb7ed4: cursor-sdk/skills/cursor-sdk/references/auth.md line 45.

The text reads:

The non-null assertion (!) is a readable way to say "fail loudly if the env var is missing" — otherwise the SDK will throw an auth error later and the stack trace won't point at the env var.

for the example apiKey: process.env.CURSOR_API_KEY!.

Problem

In TypeScript the postfix ! is a compile-time-only assertion; it is erased in emitted JavaScript and performs no runtime check. If CURSOR_API_KEY is unset, undefined is passed through and the failure appears later in the SDK, exactly the outcome the sentence says ! avoids.

Suggested fix

Reword to say that ! only silences the type error and does no check, and lead with the explicit check that is already shown a few lines below:

const apiKey = process.env.CURSOR_API_KEY;
if (!apiKey) {
  console.error("Missing CURSOR_API_KEY. ...");
  process.exit(1);
}