Installing a browser extension means handing it some access, so asking what it reaches is the right instinct. The short version: ReplySurge runs on six social domains and nowhere else, it reads the post you ask it to reply to, and it never reads what is on your clipboard.
This page is the human version, written for somebody deciding whether to click Add to Chrome. It describes what ReplySurge actually does, permission by permission, in the same words the code uses. The full privacy policy is the legal document, and it is the one that governs.
Everything below is checked against the extension's own manifest, the file Chrome reads to decide what ReplySurge is allowed to touch. Where a claim depends on browser enforcement rather than good intentions, that is called out, because those are the claims worth trusting.
ReplySurge runs on six domains, and nowhere else. Its content scripts, the only ReplySurge code that loads inside a web page, are registered in the manifest for exactly this list:
On your banking site, your webmail, your company's internal tools, your health portal or any other page you open, no ReplySurge code loads at all. Chrome enforces that from the manifest, so it is not a policy you have to take on faith. If ReplySurge ever wanted a seventh site, Chrome would have to ask you to approve the new permission before the update installed.
There is one more host in the list, and it is not a website you browse: the ReplySurge backend on Cloudflare Workers. That is the address the extension talks to when it asks for a draft. Naming it is the honest version of "sends data to our server", because it is the only place a ReplySurge request goes.
Chrome shows permission names, not purposes. Here is the name, what the browser grants, and the specific job ReplySurge uses it for.
| Permission | What the browser grants | What ReplySurge uses it for |
|---|---|---|
| storage | Saving data in the extension's own storage area in your browser. | Keeping your company profiles, tone and promotion settings, daily goal counts, voice examples and sign-in session on your machine. |
| sidePanel | Opening a panel in the browser's side panel area. | Showing the ReplySurge panel itself. That is its only use. |
| activeTab | Temporary access to the tab you are on, at the moment you invoke the extension. | Reading the post in the tab you are looking at so the draft is about that post. The reader returns nothing when the tab is not X, Reddit or LinkedIn. |
| scripting | Running a piece of code inside a page the extension already has access to. | Two jobs only: pulling the post text out of the page, and putting the finished draft into the reply box. |
| clipboardWrite | Putting text on your clipboard. | Copying the finished draft, both for the Copy button and as the fallback when a site blocks the automatic paste. |
| clipboardRead | Required by Chrome for the in-page paste command, and for reading the clipboard. | Only the paste command. ReplySurge pastes its own draft into the composer. It has no code that reads clipboard contents. |
| identity | Running a sign-in flow in a browser window and getting the result back. | Google Sign-In, requesting your email, name and profile basics, so your plan and your profiles follow your account. |
| Site access | The list of sites the extension may read and act on. | x.com, twitter.com, www.linkedin.com, reddit.com, www.reddit.com, old.reddit.com, plus the ReplySurge backend. |
This table reflects the ReplySurge extension manifest at the time of writing (version 1.0.1). Permissions can change in a future release, and Chrome will ask you to approve any new one. The governing document is the ReplySurge privacy policy.
ReplySurge asks for clipboard access so it can put its own draft into the reply box for you. The flow is: ReplySurge writes the draft to the clipboard, then triggers a paste inside the composer you are typing in. Chrome gates that in-page paste command behind the clipboardRead permission, so the permission shows up on the install screen even though ReplySurge never looks at what was on your clipboard before.
The reason ReplySurge pastes rather than typing the text in directly is unglamorous and worth stating. X's composer is built on DraftJS and LinkedIn's on Quill, and inserting text into those editors programmatically corrupts their internal state, which shows up as ghost text you cannot delete or a reply that duplicates itself on your next keystroke. A real paste goes through the editor's own paste handling, which those editors get right. Reddit's plain text boxes need none of this, and ReplySurge fills those directly.
Two details that follow from how this is built. First, ReplySurge replaces what is in the composer rather than appending to it, and it checks whether the draft is already there so a second click cannot stack two copies. Second, when a site or the browser blocks the automatic paste, ReplySurge leaves the draft on your clipboard and tells you to press the paste shortcut yourself, which is the entire fallback.
If you want to check rather than trust, the thing to look for in an extension is a call that reads the clipboard, navigator.clipboard.readText. ReplySurge does not contain one.
Yes, one specific piece of text does, and only when you ask for a draft. ReplySurge is not an on-device model. When you press generate, it sends a request to the ReplySurge backend, which calls the AI model and sends the draft back. Nothing is sent while you simply browse.
What is in that request:
What is not in it: the rest of the page, your feed, your other tabs, your browsing history, your clipboard, and any post you did not ask about. On what happens to that text afterwards, the privacy policy is the statement of record: it says post text submitted for reply generation is processed to create your draft and is not retained long-term. Read the full policy for the retention, subprocessor and rights sections in their exact wording.
One more thing ReplySurge watches, because hiding it would be worse than explaining it. On X, the extension can tell when you actually post a reply, so it can count it toward your daily goal and learn from the version you really published rather than the draft it suggested. That check looks only at X's own post request on x.com, and the text it captures is your own reply.
Most of what ReplySurge keeps lives in your browser's extension storage, on your machine. That covers your company profiles, your tone and promotion settings, your daily goal counts, the recent replies kept as voice examples, and your sign-in session. You can delete company profiles from inside the extension, and uninstalling removes the extension's local storage the way it does for any Chrome extension.
Two things live on the ReplySurge backend as well. Your account, which is the email address and name Google Sign-In returns, and your billing status, which comes from Stripe, so ReplySurge knows which plan you are on without ever seeing your card number. If you are signed in, your company profiles are also synced to your account, which is what lets the same profile show up when you install ReplySurge on another computer. If you never sign in, the profiles stay local.
ReplySurge does not sell personal data, and it uses a small set of named providers for hosting, AI inference, payments, sign-in, analytics and email. They are listed by name in the privacy policy, which is also where to send a deletion or export request.
Four limits that come from how the extension is built, not from a promise in a policy document.
ReplySurge writes a draft into the reply box and stops. You read it, edit it, and press the platform's own post button. There is no scheduler and no queue, which is exactly why using ReplySurge leaves no automation footprint on your account.
The ReplySurge button attaches to reply and comment composers only. On LinkedIn the messaging composer is explicitly excluded in the code, so the button never appears in a DM thread, and ReplySurge never sends that text anywhere.
No ReplySurge code loads on any site outside the six social domains, so there is nothing running on your bank, your inbox or your internal tools to see anything. The browser is what enforces that boundary.
The clipboard permission exists so ReplySurge can paste its own draft into a composer that would otherwise mangle inserted text. Whatever you copied before stays your business, and ReplySurge contains no code that reads it.
The legal detail lives in the full privacy policy. To see what ReplySurge does with all of this, start on the home page, or compare it with other tools as a ReplyGuy alternative and an Engage AI alternative.
Six social domains, the post you ask about, and nothing else. Add ReplySurge and write on-brand replies you paste yourself.