The extension ships across Chrome, Firefox, and Safari. It has three capabilities.
Context menu
Select text on any webpage, right-click, and create an Isonomia argument pre-populated with the selection, the page URL, and the page title. The URL is resolved through the same six-stage citation engine used everywhere else, so the evidence arrives with verified bibliographic metadata and a Wayback snapshot rather than as a bare link.
Inline previews
A content script detects Isonomia argument and claim links on Reddit, X (Twitter), and Hacker News, and injects rich inline previews showing the claim text, the argumentation scheme, the confidence, the evidence count, and the author. Readers see the structure of an argument without leaving the page they are on.
Popup composer
A compact Quick Argument Builder embedded in the extension popup lets you construct a structured argument (claim, premises, evidence) and generate a shareable link in one click, along with a list of your recent arguments.
How it relates to the rest of Isonomia
Every argument created through the extension is a first-class argument in the graph: it lands in your personal deliberation, resolves to a public permalink, and is citable and challengeable like any other. The same write primitive is exposed to agents as propose_structured_argument over the Model Context Protocol — see the argument graph docs.