# Anti-detect browser for AI agents > An anti-detect browser for AI agents gives each account the agent works in its own profile. Mosaic's MCP server and REST API let it drive them on your computer. Source: https://mosaicbrowser.com/use-cases/ai-agents ## Anti-detect browser for AI agents An anti-detect browser for AI agents gives the agent a real, headed browser profile per account, with its own fingerprint, cookies and proxy exit that persist between runs. Mosaic exposes those profiles to an agent through a built-in MCP server and a local REST API, on Pro. ![Browser profiles an assistant can drive, beside a screenshot: the Mosaic MCP server: let an AI assistant manage profiles, proxies and launches](https://mosaicbrowser.com/covers/ai-agents.webp) An agent that works in a website on your behalf needs what you need when you sign in: a browser that keeps its cookies between sessions, comes from a sensible address and looks like one ordinary computer. When the agent works across several of your accounts, each one needs that separately, or the agent becomes the thing that joins them. Mosaic gives every account a profile and lets an agent create, start and drive those profiles through a Model Context Protocol server built into the app. ## What the sites you automate allow Automation rules belong to each site, and they differ. Instagram's Terms of Use, for one, forbid accessing or collecting information "in unauthorized ways", including in an automated way, without Instagram's express permission (Instagram Help Center, read 2 November 2026). Read the terms of the site your agent works in before you point it there. Mosaic is for automating your own accounts within those terms. It keeps accounts you are entitled to run apart; it does not change what a site allows, and we do not build for scraping behind a login you were not given or for making accounts in bulk. ## Why a hosted or headless browser is the wrong default A common setup gives the agent a fresh Chromium for each task, often headless, run locally or by a hosted service. That is fine for reading public pages. It goes wrong for signed-in work for three reasons. A headless Chrome names itself in its User-Agent and drops the real GPU. A fresh browser every run has no cookies, so the site sees a new device each morning and asks for a code. And a hosted browser comes out of its host's addresses unless you give it a proxy of your own. Mosaic profiles are the opposite on each count. The browser is Tesseract Chrome, our own Chromium with fingerprint values changed in C++ inside the engine, headed, on your computer. The profile keeps its cookie jar between runs. Its proxy is its own, checked before every launch, and its timezone and language follow the exit. Background work can run off-screen: the window is parked outside the visible desktop, and the browser stays headed, with the real GPU. Mosaic is a desktop app Email yourself the link and open it on your computer. [How it works: MCP server](https://mosaicbrowser.com/features/mcp-server) ## Two ways in: MCP and the REST API ### MCP, for an assistant Turn the server on in Settings › MCP, make an API key on the API screen and paste the config block into your client. The server registers more than 150 tools: profiles and projects, proxies and providers, cookies and two-factor codes, and the live page. The [MCP server page](https://mosaicbrowser.com/features/mcp-server) lists them by group. The Model Context Protocol itself is an open standard for connecting AI applications to tools and data (modelcontextprotocol.io, read 2 November 2026). ### REST, for your own agent code The [local REST API](https://mosaicbrowser.com/features/rest-api) runs at `http://127.0.0.1:7317/api/v1`. `POST /profiles/:id/start` returns a `wsEndpoint`, and Playwright's `connectOverCDP` attaches to it (Playwright docs, read 2 November 2026), so a framework that already speaks Playwright gets a browser with the profile's fingerprint, proxy and cookies applied. ![Mosaic's MCP settings: the server switch, port 39218 and the stdio config block for an MCP client](https://mosaicbrowser.com/shots/settings-mcp.png) *Settings › MCP: off by default, with the config block to paste* ## How the agent reads and clicks a page `page_snapshot` returns the page as a tree of roles, names and states, with a `ref` on everything the agent can press or type into. That is a few hundred lines where the HTML is tens of thousands. A ref belongs to the snapshot that made it, so after a navigation an old ref is refused by name instead of landing on whatever now sits in that spot. None of the page tools enable the DevTools `Runtime` domain. We measured that one call flipping a bot detector to its bot verdict, and Playwright turns it on as soon as it attaches, which is why the page tools are a separate implementation. Snapshots and queries run in an isolated world the page cannot see. Clicks go through a cursor that travels to the element, keys are typed with human timing, and scrolling uses a real wheel. ## Guard rails for an agent with your sessions An agent with access to logged-in browsers can do real damage, so the server starts switched off and every request needs an API key. Calls appear on the API activity screen under the key that made them. A destructive call with no scope, such as emptying the trash without naming what to empty, is refused rather than read as "all of it". An unknown field is refused with the field named, because a model cannot ask what was meant. ## Limits Both automation surfaces are Pro only. Mosaic is a desktop app: no Docker, no headless server mode, no hosted endpoint, and the API answers on `127.0.0.1` alone, so the agent runs on the same computer. Profiles stay on that computer too, as [local first](https://mosaicbrowser.com/features/local-first) explains. Free covers 3 profiles; Pro is $49 a month with a 14-day free trial, on the [pricing page](https://mosaicbrowser.com/pricing). ## Sources 1. [Model Context Protocol: What is MCP?](https://modelcontextprotocol.io/docs/2026-07-28/getting-started/intro), read November 2, 2026 2. [Playwright docs: BrowserType.connectOverCDP](https://playwright.dev/docs/api/class-browsertype#browser-type-connect-over-cdp), read November 2, 2026 3. [Instagram Help Center: Terms of Use](https://help.instagram.com/581066165581870), read November 2, 2026 ## Questions ### Which AI assistants can use Mosaic? Any client that speaks the Model Context Protocol, Claude included. Most clients launch a local command over stdio, so Mosaic writes a small bridge script and Settings › MCP prints the config block to paste. ### Can my agent run Mosaic on a server? No. Mosaic is a desktop app, and both the MCP server and the REST API answer only on 127.0.0.1. There is no Docker image and no hosted endpoint. ### Is the MCP server on the Free plan? No. The MCP server and the REST API are part of Pro, $49 a month with a 14-day free trial. Free has every browser feature but neither automation surface. ### Will a site know an agent is driving the browser? A site can judge behaviour as well as the browser, and what it decides is its call. Mosaic's page tools never enable the DevTools Runtime domain, which we measured flipping a detector to its bot verdict, and they click and type through human-timed input. ## Related [An anti-detect browser MCP server for your AI assistant](https://mosaicbrowser.com/features/mcp-server): Mosaic's anti-detect browser MCP server lets Claude or any MCP client create, launch and drive your profiles. 150+ tools, off by default, key-gated. [Anti-detect browser REST API: profiles from your scripts](https://mosaicbrowser.com/features/rest-api): Mosaic's anti-detect browser REST API runs on 127.0.0.1 with API keys. Create and start profiles, then attach Puppeteer or Playwright over CDP. [An anti-detect browser with its own Chromium engine](https://mosaicbrowser.com/features/engine): Mosaic is an anti-detect browser with its own Chromium engine, Tesseract Chrome: stock source plus 64 patches that change fingerprint values in C++. [Local first: your profiles stay on your computer](https://mosaicbrowser.com/features/local-first): Mosaic has no cloud copy of your profiles. Profiles, cookies and proxies stay on your computer, encrypted on disk, with app lock, daily backups and a trash. [What is an anti-detect browser?](https://mosaicbrowser.com/guides/what-is-an-anti-detect-browser): An anti-detect browser gives each profile its own fingerprint, proxy and cookies, so sites see separate visitors. What it changes, how, and its limits.    ## Set Mosaic up for ai agents Projects per client, a preset that mints each profile its own exit, and logins with 2FA codes kept per profile. Free holds 3 profiles. Pro is $49 a month for any number. Mosaic is a desktop app Email yourself the link and open it on your computer.