Allow or block a site for an agent
Each agent has its own rules for sites. Sval asks you the first time an agent opens a site, and your answer becomes a rule for that site. You can also set rules yourself before the agent gets there.
Your agent is researching flights. You want it to read any travel site, and you never want it on your bank’s site.
Answer when an agent opens a new site
Section titled “Answer when an agent opens a new site”Sval asks in the agent’s window, and brings that window forward.
- Read which site the agent wants to open.
- Optional: where the alert shows Remember for, choose the address alone or the whole site.
- Select Allow, Allow all sites, read only, or Deny.
With the default as it starts, Allow lets the agent read the site and asks you before it sends anything there. Deny blocks the site for this agent. Allow all sites, read only lets the agent open any site with no rule, to read only.
Add a rule in Settings
Section titled “Add a rule in Settings”- Open Settings › Agents.
- Under Paired agents, select Permissions next to the agent.
- Under Site rules, select Add site.
- Type the site, or paste an address from the agent’s tab.
- Choose a level: Blocked, Read only, Ask before writes, or Full.
- Select Add.
Change or remove a rule
Section titled “Change or remove a rule”- Open the agent’s Permissions page.
- In the site’s row, choose another level under Access.
To remove a rule, select Remove rule at the end of its row. The default for sites with no rule then applies there, or the rule for the whole site. The page offers Undo.
Details
Section titled “Details”- The levels are these:
- Blocked: the agent can’t open the site.
- Read only: the agent reads pages. It never clicks, types, or submits.
- Ask before writes: the agent reads freely. Sval asks you before it clicks, types, or submits.
- Full: the agent clicks, types, and submits on its own, without asking.
- Default for sites with no rule starts at Ask on first visit. You can set it to any level, and then sites with no rule get it without asking.
- Even with a default level, Sval asks first before an agent opens a service on this computer or a device on your local network.
- On an address like nas.example.com, you choose whether the rule covers that address alone or all of example.com. A rule for one address wins over the rule for its whole site.
- When Sval asks before writes, it lists what the page is about to send. Always allow writes sets the site to Full. Always deny writes sets it to Read only.
- Downloads, Uploads, Console, and Apps each have their own column in the rules table. Each starts at Ask, and Sval asks the first time an agent needs it on that site.
- For a download or an upload, Allow and Deny answer once. The Always choices save a rule for the site.
- Sval remembers your answer about a site’s console.
- An upload rule allows files only from the folders you approved when Sval asked. You choose This folder only or This folder and the folders inside it.
- Apps lists each app a site asked to open, once it has asked.
- Rules belong to the app. Every session of the app follows them.
- Rules are kept on this device.
If something goes wrong
Section titled “If something goes wrong”- already has a rule. The site has a rule already. Select Show it to find it in the table.
- Enter a site like ebay.co.uk, or paste an address. Sval couldn’t read what you typed as a site.
Related pages
Section titled “Related pages”© 2026 Ellm Tree, Inc. Sval is not officially associated with Mozilla or its products. Firefox is a trademark of the Mozilla Foundation in the US and other countries.