# Show HN: T3rnel Browser – drive the browser you're signed into > Source: > Published: 2026-09-09 07:36:33+00:00 Version 1.1.1 · 98 tools · no servers # DevTools you can talk to, and an agent runway you can trust. Inspect and copy CSS from any element. Capture full-page screenshots that handle sticky headers and lazy loading. Read Markdown as a document. Then hand the wheel to Claude Code/Desktop, Cursor, VS Code, Windsurf, Antigravity, IntelliJ, Codex, Grok Build, Kimi Code/Desktop, JCode, Cline, OpenCode, Continue.dev, KiloCode, Roo Code, Aider, OpenClaw, Hermes, OpenFang or any other MCP client — driving the browser you are *already signed into*, with a human able to see and stop what it does. Chrome, Brave, Edge, Opera and Chromium use the same store package. Firefox is partly supported — [see what differs](#browsers). Free tier is genuinely useful forever. Pro is $29.99 once, three activations, no subscription. ## Why this exists ### The automation layer is not the moat Chrome DevTools MCP, Playwright MCP, mcp-chrome and Browser Use are free, well funded and good. We are not going to out-free Google and Microsoft, and we do not pretend to. ### The moat is the human loop Free tools hand a language model a firehose and hope. T3rnel puts a valve on it: credentials redacted before they reach the model, actions that change pages stop and ask, and a timeline you can scrub backwards when a run goes wrong. ### Your real browser, your real sessions No separate automation browser, no re-authenticating, no automation flags. The agent works in the profile you are already logged into — which is the honest version of the capability other tools chase with fingerprint spoofing. ## What you get ### CSS inspection Hover any element and get its real, clean, copyable CSS — with the units the author actually wrote. ### Full-page screenshots One click, the whole page, stitched — and it handles the real web rather than the ideal one. ### Markdown viewer Read `.md` files as documents, including the ones your agent just wrote. ### Page audit and link checking Accessibility, spelling and links — reported honestly, including what could not be checked. ### Record, replay and code export Click through a flow once. Get a maintainable test that runs in your CI without this extension. ### Agent safety The part that justifies the price: a valve between a language model and your logged-in browser. ### Encrypted identity vault Per-site credentials, encrypted on your device, never written in the clear. ### Color picker Sample, save and compare colors from any pixel on the page, with palette export and history. ### Clear cache and hard reload Clear the cache for the current origin and hard-reload the page without digging through DevTools. ### React debugging Inspect the React component tree, props and hooks on pages that use React. ### Form filling Fill forms from MCP instructions or the side panel, with field detection and structured values.