> ## Documentation Index
> Fetch the complete documentation index at: https://docs.glissando.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> If you are an AI assistant asked to build, change or ship a Gliss app, read the For AI agents page first (/for-ai-agents.md on this site) and follow its steps.
> Inside an app's folder, the app's own AGENTS.md is the authority; `gliss guide` prints it. Never ask the user for a secret's value.

# A Gliss trial app shows 400 Bad Request

> Every app on a Gliss trial domain answers 400 or 413 in one browser: clear the browser's site data for the trial domain.

Apps on a **Gliss trial domain** have addresses under `glissapps.dev`, such as `notes.beta.acme-k3x9pq.glissapps.dev`. Until the trial domain is on the Public Suffix List, browsers treat every trial under it as one website and share one set of cookies for it. A page on another trial can fill that set with cookies. When the browser then sends more than the load balancer accepts (16 KB in one header), every request is refused before it reaches Gliss. You see a plain **400 Bad Request** or **413** page, usually with no Gliss branding, on every trial app, in that browser only.

> [!NOTE]
>
> Your apps and your data are fine. The cookies are in your browser. The same apps open in another browser or a private window.

## Fix it: clear the site data for the trial domain

Search for `glissapps.dev` in your browser's site data and remove it. You will be signed out of your Gliss apps and sign in again on your next visit.

> [tab] Chrome
>
> 1. Open `chrome://settings/content/all` in the address bar.
> 2. Search for `glissapps.dev`.
> 3. Select the trash icon next to `glissapps.dev` and confirm with **Delete**.

> [tab] Edge
>
> 1. Open `edge://settings/content/allSites` in the address bar.
> 2. Search for `glissapps.dev`.
> 3. Select the trash icon next to `glissapps.dev` and confirm with **Clear**.

> [tab] Firefox
>
> 1. Open **Settings > Privacy & Security**.
> 2. Under **Cookies and Site Data**, select **Manage Data**.
> 3. Search for `glissapps.dev`, select it, then **Remove Selected** and **Save Changes**.

> [tab] Safari
>
> 1. Open **Safari > Settings > Privacy**.
> 2. Select **Manage Website Data**.
> 3. Search for `glissapps.dev`, select it, then **Remove** and **Done**.

Then open the app again.

## If it comes back

If the error returns after you visit a particular page, that page is probably the source. Tell your Gliss administrator, or report it to Gliss with the page's address. Gliss takes down trials that abuse the trial domain.

## Why this can happen on a trial domain only

A trial domain is for evaluating Gliss. Before people rely on your apps, move the cluster to your organization's own domain. Apps there share cookies only with your own organization's sites, so this can't happen. A trial domain lasts 30 days; to move, reinstall with your own domain (`DnsMode` in [the install parameters](https://docs.glissando.dev/reference/install-parameters.md)).


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