When you install a third-party app on Linnworks, the install creates a long-lasting token for your account, and the app uses that token, together with its own ID and secret, to open sessions on the Linnworks API. The app never needs your Linnworks password, but the token keeps working after each session ends, so the questions that matter are which parts of your account the app uses and how carefully it keeps that token.
This post sets out what Linnworks' own developer and help pages say about installing an app, what the token is, and what to ask a developer before you click install. Where those pages don't confirm something, such as the exact steps to remove an app, we say so rather than guess.
What happens when you install a Linnworks app?
Apps reach your account in one of two ways. Some are listed in the APPS section of Linnworks, which Linnworks' help centre describes as the Application Store. Others are installed from an installation URL that the developer gives you. Either way, the System Integration setup guide explains that the installation URL is what installs the application onto a Linnworks account, that the app's description is shown to you during installation, and that you always install the latest version of the app.
Most apps that talk to your data use a module Linnworks calls an External Application. According to the help article on setting up an External Application, this module generates a long-lasting token when you install the app. The token then goes to the developer in one of two ways:
- Shown to you. Linnworks displays the token after installation, and you paste it into the developer's system.
- Posted back. If the developer has set a postback URL, Linnworks sends the token straight to their server and you never see it.
The second route is tidier for you, but it means the app's server receives a working credential for your account the moment you finish the install. That's normal. It's also why the rest of this post is about what happens to that token next.
What access does a Linnworks app get from that token?
The token on its own isn't a session. The setup guide says the app exchanges it for a session token by calling AuthorizeByApplication with three things: its application ID, its application secret and your permanent token. The session token has a limited lifetime. When it expires, the app authorises again with the same permanent token. The authentication guide puts it simply: the access token is used to create a session, and the session is used to talk to the API.
In practice, that means installing an app gives it ongoing access, not one visit. As long as the app holds the token and its own secret, it can open a new session whenever it needs one, including while you're asleep. Linnworks' applications overview describes this as an authorisation service that lets an app work with your account without having your password, under a defined set of rules and permissions.
Linnworks also publishes a list of permissions nodes in its Application Manifest help section. It covers areas such as open, processed and returned orders, inventory and stock, purchase orders, customers, settings, dashboards, and account and billing pages. That page lists the nodes but doesn't explain how they apply to a particular app, so don't treat it as a checklist you'll be shown at install. Ask the developer instead which of those areas their app reads, and which it changes.
Is an app's token the same as a Linnworks API key?
It does the job people usually mean by an API key. The authentication guide says an access token is obtained by a user installing an application, and even a developer testing their own app gets one that way. So there is normally no separate key for you to copy out of Linnworks. If an app asks for your Linnworks username and password instead, ask why: the documented install flow doesn't need them.
What to check before you install a Linnworks app
None of these questions is a trick. A developer who has thought about security will answer them in a sentence each.
- What does it read, and what does it change? An app that only reports on orders is a different risk from one that edits prices or archives stock. Apps that change data should show you the change first, the pattern we describe in how to decide what an AI agent may do on its own.
- Does it copy your data, and where to? Some apps read live and keep nothing. Others store orders or stock in their own database. Ask where that database is and how long records are kept.
- How is the token stored? The token is a working credential for your account. It should be encrypted at rest and never written to logs.
- Who supports it, and what does it cost? Linnworks' Application Store article says some apps are paid, asks you to read the terms for third-party apps before installing, and says technical support for third-party apps comes from the developer directly.
- What happens when you disconnect? Ask whether disconnecting deletes the token and any copied data, or just hides the app.
How one app handles the token: an example
The Hosted MCP Server for Linnworks, which is coming very soon, is built by the team behind this site, so we can show you its code rather than describe it from the outside. Here is what its connect flow does with your token:
- It ties the install to your account. When you press Connect, it sends you to Linnworks' install page with a signed tracking code that expires after 24 hours. When the token comes back, the code must match your account, or nothing is saved.
- It tests the token before keeping it. It calls AuthorizeByApplication straight away. If Linnworks doesn't accept the token, the app tells you so and stores nothing.
- It stores the token encrypted. The token is encrypted before it is saved. The short-lived session is cached for about 25 minutes, then a new one is opened from the token.
- Disconnect deletes its copy. Pressing Disconnect deletes the stored token and the cached session, and marks your account as not connected.
Note what that last step does and doesn't do. It removes the app's copy of the token. It's a separate thing from anything you do inside Linnworks itself. You can read more about what the service does in our introduction to the Hosted MCP Server for Linnworks.
Removing a Linnworks app: what we couldn't confirm
The Linnworks developer and help pages we read cover installing an app and using its token in detail. They don't set out the steps to uninstall an app, and they don't say whether uninstalling stops the app's token from working. We'd rather tell you that than describe a menu we haven't been able to check.
Until you've confirmed it for your own account, treat removal as three steps:
- Disconnect inside the app, and ask the developer to confirm in writing that your token and any copied data have been deleted.
- Ask Linnworks support how to remove the app from your account, and whether that ends the app's access.
- Check that the app can no longer show you any of your data.
If you're tidying up more than apps, the same careful approach applies to your catalogue: see how to archive Linnworks stock items safely.
Want to ask Claude about your Linnworks orders, stock and purchase orders, with a token you can see handled in the open? Join the waiting list for the Hosted MCP Server for Linnworks.