Is Substack Notes Scheduler + LinkedIn AI safe on LinkedIn in 2026?

No — LinkedIn detects Substack Notes Scheduler + LinkedIn AI (we checked it November 14, 2026). Substack Notes Scheduler + LinkedIn AI's extension ID is on LinkedIn's AED detection list (Nov 2026 snapshot), and LinkedIn's page code checks for Substack Notes Scheduler + LinkedIn AI on every visit by requesting chrome-extension://fjbcjlkbhpapjnhaaiamclcnhbckljef/medium-main-world-injector.js — a file that exists only if Substack Notes Scheduler + LinkedIn AI is installed. Our automated scan of Substack Notes Scheduler + LinkedIn AI 1.1.54 found code that references LinkedIn's session cookie li_at (11 matches in 1 files); whether Substack Notes Scheduler + LinkedIn AI sends that cookie anywhere needs a manual dataflow review.

Updated November 14, 2026 · LinkedIn AED snapshot Nov 2026

ID: fjbcjlkbhpapjnhaaiamclcnhbckljef

Does LinkedIn detect Substack Notes Scheduler + LinkedIn AI? What we found in its code

Detected by LinkedIn

This browser extension is actively compiled into LinkedIn's frontend detection lists. LinkedIn's scripts can detect when this is active on your browser.

LinkedIn requests: chrome-extension://fjbcjlkbhpapjnhaaiamclcnhbckljef/medium-main-world-injector.js

DETECTED

What this means: detection isn't an instant ban — it's one input to LinkedIn's risk score. But it's a standing signal: it stacks with your behavior (volume, programmatic clicks) and device fingerprint, and this is just the AED list — one of LinkedIn's three detection systems (see how it works).

What our automated scan found in Substack Notes Scheduler + LinkedIn AI's code

We downloaded Substack Notes Scheduler + LinkedIn AI version 1.1.54 from the Chrome Web Store on November 2, 2026 and searched its 16 code files for the patterns below. Each line shows the first place we found it.

Substack Notes Scheduler + LinkedIn AI's code references li_at — LinkedIn's session cookie, the one that keeps you logged in. 11 matches in 1 file — first at background.js:1.
Substack Notes Scheduler + LinkedIn AI's code references JSESSIONID — LinkedIn's CSRF cookie, needed to call LinkedIn's internal API as you. 7 matches in 2 files — first at background.js:1.
Substack Notes Scheduler + LinkedIn AI's code calls paths of LinkedIn's internal Voyager API (voyager/api). 14 matches in 2 files — first at linkedin-main-world-injector.js:1.
Substack Notes Scheduler + LinkedIn AI uses the Chrome cookies API (chrome.cookies), which reads cookies of every site it has access to. 15 matches in 1 file — first at background.js:1.
Substack Notes Scheduler + LinkedIn AI reads or writes document.cookie inside pages. 1 match in 1 file — first at linkedin-main-world-injector.js:1.
Substack Notes Scheduler + LinkedIn AI creates synthetic clicks or keystrokes (dispatchEvent / MouseEvent) — LinkedIn can tell these from real input (isTrusted=false). 149 matches in 6 files — first at background.js:1.
Substack Notes Scheduler + LinkedIn AI makes its own network requests (fetch / XHR / WebSocket). 48 matches in 7 files — first at background.js:1.
Substack Notes Scheduler + LinkedIn AI's code mentions linkedin.com. 45 matches in 5 files — first at background.js:1.

Permissions Substack Notes Scheduler + LinkedIn AI asks for

scriptingclipboardReadclipboardWritetabsalarmsstoragecookiesoffscreenhttps://www.narrareach.com/*https://www.narrareach.com/dashboard/*https://narrareach.com/*https://medium.com/*https://linkedin.com/*https://www.linkedin.com/*https://*.linkedin.com/*https://substack.com/*https://*.substack.com/*

What this scan is — and isn't. It is an automated static search of the shipped package, not a full teardown: a match means the pattern is in the code, not that Substack Notes Scheduler + LinkedIn AI misuses it, and no match doesn't prove absence (minified or runtime-built code can hide it). We haven't traced where Substack Notes Scheduler + LinkedIn AI sends data. How we test

How LinkedIn checks for Substack Notes Scheduler + LinkedIn AI: the AED probe

That verdict isn't a guess. This is what LinkedIn's own page code does on every visit — simplified from its production bundle, which the BrowserGate investigation reverse-engineered line by line:

// LinkedIn's page bundle — simplified from BrowserGate's teardown

const hits = [];

for (const { id, file } of AED_LIST) // 4,934 ids incl. this one

try { await fetch("chrome-extension://" + id + "/" + file); hits.push(id); }

catch {} // not installed → silently swallowed

fireTrackingPayload("AedEvent", { browserExtensionIds: hits }); // → POST /li/track

// this extension is probed at:
// chrome-extension://fjbcjlkbhpapjnhaaiamclcnhbckljef/medium-main-world-injector.js

On LinkedIn’s AED list

Yes

1 of 4,934 · snapshot Nov 2026

URL LinkedIn requests

chrome-extension://fjbcjlkbhpapjnhaaiamclcnhbckljef/medium-main-world-injector.js

the extension's ID + a file bundled inside it

Store status

Live on the Web Store

Source

LinkedIn bundle

ℹVerify it yourself: on linkedin.com open DevTools → Sources and search the page bundle for fjbcjlkbhpap… or AedEvent; or Network → filter li/track to watch the verdict ship. The scan runs even in Incognito. Below — the full code-level teardown.

Substack Notes Scheduler + LinkedIn AI — marketed on the Chrome Web Store, detected by LinkedIn — Vendor's own Chrome Web Store screenshot — this extension is on LinkedIn's detection list.

How LinkedIn fingerprints your browser while you use Substack Notes Scheduler + LinkedIn AI

Even after a cookie is copied out, LinkedIn keeps one more receipt on every request that follows — a 48-point snapshot of the exact machine making it. Faking it convincingly means reproducing that machine's quirks, not just editing a string.

Click any signal above for what it means. These are illustrative values — this demo never reads your actual device.

Your 48-point fingerprint — RSA-encrypted, attached to every API call in this session, not just login

This extension runs inside your real browser, so its requests always carry your real fingerprint — that isn't something it controls, it's simply where its code executes.

Verified against LinkedIn source-code, Nov 2026 snapshot.Read full study