Install Sephir
One click to add it to your browser. The free tier needs no account — connect your own ChatGPT, Claude or Gemini key and the agent works in any tab.
After you install
A welcome tab opens automatically with the two-minute setup: pick a provider, paste a key, run your first agent turn.
Firefox and other browsers
The Chrome listing covers Chrome, Edge, Brave, Arc and Opera. A Firefox build ships alongside it.