Why we built Sigil

Browser agents are crossing the line from answering questions to doing real work: filing expenses, updating records, pulling reports from the dozen tools you use every day. That shift is exciting, and it is also where the risk starts.

The problem with giving an agent a browser

Most agent tools open a brand-new browser somewhere in the cloud, show the AI a copy of whatever is on the page, and trust a written instruction to keep it in line. That approach has three problems:

• It is wasteful. Sending a fresh copy of every page on every step is slow and runs up the cost.
• It is cut off from your work. A browser running on some far-off server is not signed in to your accounts or set up with the tools you already use.
• It is hard to control. “Please don’t send email” written in an instruction is a request, not a guarantee.

How Sigil is different

Sigil drives the real Chrome already on your computer. The agent works where you work, signed in to the accounts you already use. Nothing gets copied to a shared system you do not control, and the limits you set are actually enforced, not just politely asked for.

You decide exactly what the agent is allowed to touch, and that decision holds. We will go deeper on how those controls work in a future post.