Rescriptum

Rescriptum Tab

Your browser, wired to your IDE

A browser extension that lets the agent research with sources, see the element you are pointing at, and check the running page. Works in Chrome, Edge, and Brave.

Download extension (v2.0.6)Read the docs

Needs the Rescriptum IDE for file and agent features

Try it

See what the agent gets

A small interactive version of the three things you will use most.

Research · read 3 pages

React Strict Mode mounts, unmounts, and re-mounts each component once in development so missing cleanup shows up early [1]. Production builds run effects once [1][3]. Return a cleanup function and the second run is harmless [2].

  • [1]useEffect – React reference
  • [2]You Might Not Need an Effect
  • [3]Strict Mode double-invocation, explained

Sample answers for illustration. In the product, Tab searches the web and reads the pages itself.

Capabilities

What Tab does

Ask Tab: research with sources

Tab searches the web, reads up to three of the most relevant pages, and answers with numbered citations. Use it from the Tab panel, or let the agent call ask_tab mid-task. Research and Chat modes, with an option to include the page you are on.

Element picker

Press Alt+Shift+C and click anything. The pin carries the selector, outer HTML, computed styles, design tokens, and bounding box. On a React dev build it also carries the component hierarchy and the source file and line.

Live page inspection

The agent can read page text and console and network errors, click, type, scroll, screenshot, navigate, and run JavaScript. It checks a UI fix by loading the page, not by trusting the diff.

Linked, locally

The IDE and the extension talk over a loopback WebSocket on 127.0.0.1:49281. Nothing routes through a Rescriptum server, and the link reconnects on its own after an IDE restart.

Agent tools added by Tab
  • ask_tabCited research in the browser
  • tab_read_contentPage text, selection, console and network errors
  • browser_get_pinned_elementThe element you pinned, with source mapping
  • browser_qa_inspectDOM mount state, React tree, console, selector checks
  • browser_interactClick, type, scroll, wait, screenshot, read a tab
  • browser_navigateGo to a URL
  • browser_evalRun JavaScript in the page
  • browser_list_tabsOpen http and https tabs

Install

Four steps

  1. 1Download the extension zip and unzip it somewhere permanent.
  2. 2Open chrome://extensions (or edge://, brave://) and turn on Developer mode.
  3. 3Choose Load unpacked and select the folder that contains manifest.json.
  4. 4Start Rescriptum. The Tab panel shows Linked and connects automatically.

Chrome 116 or newer. Firefox is not supported today. Source file and line in pins need a React development build.

Privacy

What stays, what leaves

Link to the IDE

Stays on your machine. Bound to loopback, origin-checked.

Ask Tab and chat

Questions and the page text they rely on go to the model and search providers set up for Tab.

Page reading

Happens when you pin, ask with the active tab, or when the agent calls a browser tool in a turn you started.

API key

While linked, the IDE can share your OpenRouter key with the extension over the local link so Tab can use models.

Internal pages

chrome:// and extension pages are never tracked.

The local link has no pairing token; it relies on loopback binding and origin checks. Details in Security and privacy.

Pair it with the IDE

Tab is most useful with Rescriptum running: the agent can fix what you pin and confirm it on the page.

Download the IDETab documentation