Browser Harness is an open-source tool from the Browser Use team that lets coding agents such as Claude Code, Codex, and Cursor drive your real Chrome browser, logged in as you. One setup prompt is all it takes: the agent can then open pages, click, type, read, and download through your actual sessions. The project has over 18,000 stars on GitHub and was updated in October 2026.
Most browser automation starts from a cold, logged-out profile, which fails on any site that needs your account. Browser Harness takes the opposite approach: it connects to the Chrome you already use, through the Chrome DevTools Protocol, so agents work with your real logins, cookies, and tabs. Uniquely, the harness improves itself as it goes: when the agent hits a task it lacks a helper for, it writes the missing helper, so repeated workflows get faster and more reliable. It is MIT licensed, and an optional Browser Use Cloud mode covers cases where a managed cloud browser fits better.
Browser Harness is free and open source under the MIT license for local use. The optional Browser Use Cloud service for managed cloud browsers is paid, making the overall offering freemium.
Browser Harness is for developers who want their coding agent to handle web tasks that require real accounts: checking dashboards, filling web tools, testing logged-in flows, and automating browser chores without maintaining separate automation scripts.