---
title: "Claude Code and Claude Desktop MCP setup"
description: "Add an MCP server to Claude Code with claude mcp add over HTTP, and to the Claude desktop app over stdio, with a local browser server as the example."
canonical: "https://scalebrowser.net/docs/agents/mcp-clients/claude"
last_modified: "2026-09-22T18:16:38.000Z"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://scalebrowser.net/llms.txt
> Use this file to discover all available pages before exploring further.

# Claude Code and Claude Desktop MCP setup

> Add an MCP server to Claude Code with claude mcp add over HTTP, and to the Claude desktop app over stdio, with a local browser server as the example.

Claude Code speaks the HTTP transport directly. The Claude desktop app validates only stdio servers in its configuration file, so it takes the daemon's own stdio mode instead.

## Before you start

Everything below assumes a daemon that is already running and a token to reach it with.

<CardGroup columns={2}>
  <Card title="Windows desktop app">
    The app starts the daemon for you. The token is the contents of
    `%LOCALAPPDATA%\Scalebrowser\token`, and the address it is listening on is the
    `native_addr` field of `%LOCALAPPDATA%\Scalebrowser\runtime.json`. That is usually
    `127.0.0.1:8787`, but the app moves up a port when something else already holds it.
  </Card>
  <Card title="Self-hosted daemon">
    `scalebrowser-daemon --generate-token` prints a token and stores it under
    `<data_dir>/token`. The address is whatever `bind_addr` says, which is `127.0.0.1:8787`
    unless you changed it. See [Install & run](/docs/install#the-api-token).
  </Card>
</CardGroup>

<Warning>

**The token is a full-power credential.** It reaches every profile, every stored session
and the whole management API. Treat it like a password: keep it out of a repository, and
prefer your client's environment-variable syntax over a literal in a config file that
gets committed.

</Warning>

## Claude Code

One command, and the server is registered:

```bash
claude mcp add --transport http scalebrowser http://127.0.0.1:8787/v1/mcp \
  --header "Authorization: Bearer $SCALEBROWSER_TOKEN"
```

It writes to the current project unless you add `--scope user`. The same entry written by
hand, in a project's `.mcp.json` or in `~/.claude.json`, looks like this:

```json .mcp.json
{
  "mcpServers": {
    "scalebrowser": {
      "type": "http",
      "url": "http://127.0.0.1:8787/v1/mcp",
      "headers": { "Authorization": "Bearer <token>" }
    }
  }
}
```

<Warning>

**Leaving out `type` is a silent failure, not a default.** Claude Code reads an entry that
has a `url` but no `type` as a stdio server, skips it, and reports
`has a "url" but no "type"`. Write `"type": "http"`.

</Warning>

Check it with `claude mcp list`; the server should report as connected.

## Claude desktop app

Its `claude_desktop_config.json` validates stdio servers only, so point it at the daemon's
own stdio mode. No token appears in this file, because the process resolves it from the data
directory you name.

```json claude_desktop_config.json
{
  "mcpServers": {
    "scalebrowser": {
      "command": "C:\\Users\\<you>\\AppData\\Local\\Programs\\Scalebrowser\\resources\\daemon\\scalebrowser-daemon.exe",
      "args": ["--mcp-stdio", "--data-dir", "C:\\Users\\<you>\\AppData\\Local\\Scalebrowser"]
    }
  }
}
```

<Warning>

**`--data-dir` is not optional with the desktop app.** Without it the process looks in the
daemon's default directory, which is `%ProgramData%\Scalebrowser` on Windows and is not the
one the app uses. What happens next depends on what is in that directory, and neither
outcome announces itself: if an earlier standalone run left a `runtime.json` there, the
process finds a daemon on the address it names, attaches to it and answers every call with
`unauthorized`; if the directory is empty, it starts a second daemon that responds normally
and knows none of your profiles.

Since 0.9 the process detects both and stops with the directory it expected, the one it
found and the command that fixes it. Older builds attach silently.

</Warning>

The app's own values are in **Settings → General → Connect an agent**, ready to copy: it
fills in this exact block with the paths on your machine. The process becomes a relay to the
daemon that already owns that data directory rather than a second daemon. See
[over stdio](/docs/agents/mcp-server#over-stdio).

## Claude Code inside WSL

The HTTP entry above will not connect from a WSL shell: WSL reaches Windows over its own
network adapter, so `127.0.0.1` there is the Linux side, not Windows. Use the stdio entry,
with both paths translated. See [WSL and containers](/docs/agents/wsl-and-containers).

## What the agent can do now

Ask it to open a page and it will lease a profile, bind a tab and start reading. The tool
set, the page map and the failure shapes are on [MCP server](/docs/agents/mcp-server); what the
agent is **allowed** to do is decided by the daemon, not by the client, so see
[tool profiles](/docs/agents/mcp-server#the-tool-set).