wrangler-4-122-0-2-b

Question

Is adding no_nodejs_compat to compatibility_flags enough to opt a recent Worker out of Node.js APIs?

Answer key

A correct answer says

To turn Node.js compatibility off on a compatibility date of 2026-08-04 or later, set both `no_nodejs_compat` and `no_nodejs_compat_v2` flags.

The stale answer

Node.js compatibility is off unless you add `nodejs_compat`, so you simply leave the flag out to disable it.

The change's lesson

Answer

No, not by itself, according to the project's Ludion lessons (`.ludion/lessons.md`). With wrangler 4.122.0 or later, which is what's installed here (4.148.0), `nodejs_compat` is on by default if your `compatibility_date` is 2026-08-04 or later. To turn it off you need two steps:

1. Remove any positive flags (`nodejs_compat`, `nodejs_compat_v2`) from `compatibility_flags`.
2. Add **both** `no_nodejs_compat` and `no_nodejs_compat_v2`.

The change is silent. If you only add `no_nodejs_compat`, you get no error, so the Worker can still have Node.js APIs without you noticing. I haven't tested this myself; it comes from that lesson. To confirm it, run `wrangler dev` and check whether something like `node:buffer` still imports.

Answering cost $0.08.

Grade

correct

The judge's reason: It says no_nodejs_compat alone is insufficient and that both no_nodejs_compat and no_nodejs_compat_v2 are required for dates 2026-08-04 or later, without presenting the stale behavior as current.

The judge's log

Session log

What the agent wrote, the tools it called, and what they returned, from docs/bench/2026-10-11-done3/runs/B-project-sync/wrangler-4-122-0-2-b.jsonl. Thinking and the session's settings are left out. The raw log

1. Agent

   No, not by itself, according to the project's Ludion lessons (`.ludion/lessons.md`). With wrangler 4.122.0 or later, which is what's installed here (4.148.0), `nodejs_compat` is on by default if your `compatibility_date` is 2026-08-04 or later. To turn it off you need two steps:
   
   1. Remove any positive flags (`nodejs_compat`, `nodejs_compat_v2`) from `compatibility_flags`.
   2. Add **both** `no_nodejs_compat` and `no_nodejs_compat_v2`.
   
   The change is silent. If you only add `no_nodejs_compat`, you get no error, so the Worker can still have Node.js APIs without you noticing. I haven't tested this myself; it comes from that lesson. To confirm it, run `wrangler dev` and check whether something like `node:buffer` still imports.