Install the browser extension

Reskale needs a browser extension to do most of its job. This page explains what it is, how to install it, and exactly what it can and cannot see.

Why an extension is required

eBay and Discogs publish official APIs. Reskale uses them, over OAuth, and the extension is not involved.

Mercari, Depop and Vinted publish nothing. There is no developer programme, no listing API, no sanctioned way for outside software to post an item. The only route is the one you already use: a logged-in browser session on their own site.

That is what the extension is. It works inside your browser, using the session you established by logging in yourself, and does the same things you would do by hand — read your orders, fill a sell form, take a listing down. Nothing is impersonating you from a datacentre.

Without it, Mercari, Depop and Vinted are unavailable. eBay and Discogs still work.

Install it

1. Open the Reskale extension on the Chrome Web Store.
2. Press Add to Chrome, then confirm.
3. Reload your Reskale dashboard tab. The page checks for the extension when it loads, so a tab opened before the install will keep reporting it as missing.

Supported browsers

Mobile browsers do not support extensions. Crossposting is a desktop job.

Pin it

Click the puzzle-piece icon in the toolbar and pin Reskale. The icon is how you confirm at a glance that it is running, and the popup is where connection status lives.

What it can see

The extension declares access to five hosts and nothing else: eBay, Mercari, Poshmark, Depop and Vinted, plus their image CDNs. It cannot read your bank, your email, or any other tab.

Within those sites, it does four things:

• Reads your own seller pages — orders, offers, messages, notifications, active listings.
• Fills sell forms when you crosspost, the way you would type them.
• Takes listings down when you delist.
• Reads your session cookies for those five sites so requests run as you.

It does not touch other sellers' data, does not browse, does not follow, share, or like anything on your behalf.

What it does with your login

Your passwords are never involved. You log in on the marketplace's own site. Reskale never sees, stores, or transmits a marketplace password.

Your session token is used, and is stored encrypted. To sync in the background — new sales at 3am, without a browser tab open — Reskale's servers need the same session your browser has. That token is sent over TLS and stored encrypted at rest using AES-256-GCM. It is scoped to your account, and any attempt to read another user's row is blocked at the database level.

You can revoke it at any time in two ways, and both work immediately:

• Disconnect in Reskale, which deletes the stored credential.
• Log out on the marketplace itself, which invalidates the session everywhere, including for Reskale.

Full detail: privacy and security.

Keeping it working

• Let it update. Marketplaces change their pages without warning; a stale extension is the most common cause of crossposts that used to work and now fail. Chrome updates extensions automatically — do not disable that.
• Stay logged in. If you log out of Mercari in your browser, Reskale's connection to Mercari goes stale too.
• Leave the tabs alone. During a crosspost the extension opens background tabs on the marketplace and closes them when it is done. They are inactive, they will not steal focus, and they are not the same tabs you have open.

If the dashboard says the extension is missing

In order, these fix nearly every case:

1. Reload the Reskale tab.
2. Confirm the extension is enabled at chrome://extensions.
3. Confirm you are in the browser you installed it in — profiles do not share extensions.
4. Restart the browser.

Still stuck: troubleshooting.

Next

Connect your marketplaces.