Warp browser MCP
Hronaut runs as a separate visible Chromium application. Warp's local Agent can use it through one user-level Streamable HTTP server while named workspaces, sign-ins, and debugging state remain available between conversations.
Hronaut is an independent project and is not affiliated with or endorsed by Warp.
Local MCP endpoint
http://127.0.0.1:47812/mcpThis guide is for a local Agent in the Warp desktop app on the same computer as Hronaut. A Warp-hosted cloud agent runs elsewhere and cannot reach your desktop's loopback address.
Terminal-native fit
Warp supports URL-based Streamable HTTP and SSE servers for local agents. A global Warp MCP file makes Hronaut available across repositories and auto-spawns the server definition, while the browser remains a person-visible desktop process you can take over or pause.
User-level setup
Create or update ~/.warp/.mcp.json, then keep Hronaut running. Warp also accepts the same JSON through Settings → Agents → MCP servers → + Add.
Authentication disabled
{
"mcpServers": {
"hronaut": {
"url": "http://127.0.0.1:47812/mcp"
}
}
}A new Hronaut profile starts without MCP authentication. Any process running as your user can control that profile, so use it only where local processes are equally trusted.
Authentication enabled
{
"mcpServers": {
"hronaut": {
"url": "http://127.0.0.1:47812/mcp",
"headers": {
"Authorization": "Bearer <owner-token>"
}
}
}
}Enable Require MCP authentication in Hronaut, then replace only the placeholder with the value from the owner-only token file identified on Hronaut Home.
Warp documents custom headers but does not document file or environment interpolation for URL-server headers. Treat this global file as secret-bearing local configuration: keep it owner-readable and never put the token in a project file, chat, screenshot, shell history, or shared server definition.
Warp's current file-based MCP documentation uses ~/.warp/.mcp.json for global definitions and requires individual approval for project-scoped server files. This guide uses the global file so a cloned repository cannot silently redefine the browser connection. Current Warp MCP reference ↗
Observable verification
1 · Server state
Open Settings → Agents → MCP servers. Start hronaut if needed; a running server shows its available tools and resources.
2 · Two-sided evidence
Use View Logs on the Warp server if it fails. Then confirm Warp appears under Connections on Hronaut Home. Redact secrets before sharing MCP logs.
3 · Browser task
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.
Tool and browser authority
Warp Agent Profiles can allowlist, denylist, or let the agent decide whether to call each MCP server. Keep hronaut on the denylist or decision-based approval until you have reviewed the task and workspace. Do not use Run until completion with a valuable signed-in browser session unless you intentionally accept its broader autonomy.
Pause MCP before entering passwords, security keys, payment details, or other human-only information. Resume only after the sensitive interaction has finished.
Primary sources
One browser beyond one conversation
Named workspaces isolate cookies and storage from the human Default workspace while remaining available after a Warp Agent conversation ends or another compatible local MCP client takes over.