macOS, Linux, or Git Bash
Install and verify
curl -fsSL https://x.ai/cli/install.sh | bash
grok --versionGrok Build browser MCP
Give Grok Build a browser that survives the terminal task.
Hronaut runs a separate visible Chromium application. The local Grok Build CLI connects through native Streamable HTTP MCP while named workspaces, sign-ins, tabs, and debugging state remain available after one Grok session ends.
Hronaut is an independent project and is not affiliated with or endorsed by xAI or X.
Local MCP endpoint
http://127.0.0.1:47812/mcp
This guide is for the local Grok Build CLI running on the same computer as Hronaut. The hosted grok.com and @grok surfaces cannot reach this computer's loopback endpoint.
Official local CLI
Install Grok Build for your platform.
Use xAI's released binary installer, then confirm the command is available. Review the installer source or use the repository's source-build instructions if your environment does not permit piped installers.
Windows PowerShell
Install and verify
irm https://x.ai/cli/install.ps1 | iex
grok --versionThese are the current commands published by the official Grok Build repository ↗.
User-level setup
Add Hronaut through Grok's native HTTP transport.
Start Hronaut first. Without --scope project, Grok stores this server in the user configuration at ~/.grok/config.toml, or %USERPROFILE%\.grok\config.toml on Windows, so it remains available across repositories.
Authentication disabled
Add the loopback server
grok mcp add --transport http hronaut http://127.0.0.1:47812/mcpThis command intentionally contains no credential. A new Hronaut profile starts with MCP authentication disabled.
Equivalent user configuration
~/.grok/config.toml
[mcp_servers.hronaut]
url = "http://127.0.0.1:47812/mcp"Authentication enabled
Keep the bearer value out of TOML
[mcp_servers.hronaut]
url = "http://127.0.0.1:47812/mcp"
headers = { "Authorization" = "Bearer ${HRONAUT_MCP_TOKEN}" }Enable Require MCP authentication in Hronaut and load the owner token into HRONAUT_MCP_TOKEN before starting Grok. Grok expands environment variables in headers. Do not put the token in project configuration, chat, screenshots, or shell history.
Observable verification
Diagnose the server, then prove browser behavior.
1 · Configuration
Inspect and diagnose Hronaut
grok inspect
grok mcp list
grok mcp doctor hronautDoctor checks the saved definition and live connection instead of only confirming that TOML parses.
2 · Runtime
Watch Hronaut Home
Open Hronaut Home and confirm Grok appears under Connections. In Grok's TUI, /mcps opens the MCP server panel.
3 · Browser task
Create an isolated workspace
Ask: “Using Hronaut, create a 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.”
Expect a visible first-check workspace showing Example Domain.
Local reachability and approval
Keep browser authority visible and local.
Ask is Grok Build's default permission mode. Keep MCP browser actions reviewable when the workspace contains valuable signed-in state; do not use always-approve for an unfamiliar repository or prompt.
A new Hronaut profile starts without authentication, so any process running as your user can control it. Enable authentication for sensitive browser profiles and pause MCP before entering passwords, security keys, payment details, or other human-only information.
Hosted Grok products run outside this desktop boundary. Do not expose or tunnel Hronaut to make grok.com or @grok reach the loopback server; use the local Grok Build CLI instead.
Primary sources
Installation, configuration, and permission evidence.
- Official Grok Build repository — released installers, supported platforms, binary name, and local coding-agent scope.
- Grok Build MCP servers — HTTP transport, user and project scopes, environment-backed headers, list, doctor, and TUI management.
- Grok Build settings — user configuration paths and config discovery.
- Grok Build permissions — Ask, Auto, and Always-approve behavior.
Keep the browser; change the task
Use a named Hronaut workspace for every durable browser job.
Named workspaces isolate cookies and storage from the human Default workspace while remaining available to the next local Grok Build task—or another compatible local MCP client.