Durable browser
Restart Claude Code, keep the session
The desktop application owns Chromium and its profile. Closing one Claude Code session does not intentionally close the browser or discard its local state.
Claude Code browser MCP
Give Claude Code a browser that stays open.
Hronaut owns a separate visible Chromium browser. Claude Code connects over loopback MCP, while tabs, sign-ins, cookies, storage, windows, and named workspaces remain available between coding sessions.
Hronaut is an independent project and is not affiliated with or endorsed by Anthropic.
Local MCP endpoint
http://127.0.0.1:47812/mcp
Start Hronaut once. Claude Code can disconnect, restart, or switch repositories without owning the browser process. The endpoint listens on loopback rather than exposing a hosted browser.
The ownership difference
The browser belongs to the workspace, not one Claude Code run.
Claude Code can connect to many kinds of MCP servers. Choose Hronaut when the browser itself should remain a separate visible application with durable local state, human controls, and isolated agent workspaces. See how task, MCP transport, and browser lifetimes differ →
Human control
See, pause, and take over
Watch browser actions, pause MCP before a sensitive step, sign in yourself, then resume Claude Code inside the same browser session.
Workspace isolation
Keep tasks out of Default
Ask Claude Code to create a named Hronaut workspace. Agent workspaces use separate persistent browser profiles and do not expose the human Default workspace through MCP.
Local boundary
Browser data stays on this device
Hronaut is a local Electron/Chromium application with a loopback MCP endpoint. It is not a hosted browser, proxy, CAPTCHA service, or multi-browser CI runner.
One user-level command
Connect Claude Code to Hronaut.
Anthropic documents HTTP as the transport for URL-based MCP servers. The user scope keeps Hronaut available across repositories on this computer; use local or project scope only when you intentionally want a narrower configuration.
Authentication disabled
Run from any repository
claude mcp add --transport http --scope user hronaut http://127.0.0.1:47812/mcpClaude Code stores user-scoped servers in its user configuration and makes them available across projects. Official Claude Code MCP documentation ↗
Authentication enabled
Copy from Hronaut Home
Enable Require MCP authentication, then copy the generated Claude Code command from Hronaut Home. It reads the owner-only token file and adds the required authorization header without putting the token in this page, chat, or source control.
Verify before using a login
Prove the connection in an isolated workspace.
- 1
Check the configured server
Start Hronaut, then run
claude mcp listandclaude mcp get hronaut. The server should use HTTP and the same loopback endpoint shown on Hronaut Home. - 2
Check it inside Claude Code
Open the
/mcppanel. Confirm Hronaut is connected and exposes tools before asking it to touch a signed-in page. - 3
Create a clean first workspace
Ask: “Create a Hronaut workspace named first-check, open https://example.com inside it, and tell me the page title and workspace ID. Do not use my Default workspace.”
- 4
Confirm the observable result
A visible
first-checkworkspace opens Example Domain, and Claude Code reports its stable workspace ID.
Security boundary
Treat both the server and page content as untrusted until reviewed.
Anthropic recommends connecting only MCP servers you trust because content fetched through tools can carry prompt-injection risk. Hronaut is local and source-available, but websites can still contain malicious instructions. Keep sensitive work in a dedicated profile, review surprising requests, and use Hronaut's pause and interaction-lock controls.
A new profile starts without MCP authentication for simple local setup. In that mode, another process running as your operating-system user could connect. Before using valuable signed-in sessions, enable Require MCP authentication and copy the exact token-aware setup from Hronaut Home.
Choose deliberately
Use the browser ownership model your task actually needs.
Choose Hronaut for a separate visible browser that should outlive one Claude Code task. If repeatable ephemeral testing is the primary goal, use a test-runner-owned browser. If the agent must inspect the exact tabs already open in everyday Chrome, use a tool designed to connect to that profile instead.