Screaming Frog SEO Spider MCP Server

An MCP (Model Context Protocol) server that gives Claude (or any MCP-compatible client) programmatic access to Screaming Frog SEO Spider, crawl websites, export crawl data, and manage your crawl storage, all from your AI assistant.

See it in action

The Pre-Launch Website Audit skill for Claude Code uses this MCP server for its technical SEO and on-page audits, site-wide crawl data, custom extractions, bulk analysis across all URLs. The skill runs 5 coordinated sub-audits and works without SF (bash fallbacks), but Screaming Frog is the biggest upgrade for crawl-dependent checks.

Prerequisites

1. Screaming Frog SEO Spider installed on your machine (tested with v23.x, should work with v16+). Download from: https://www.screamingfrog.co.uk/seo-spider/

2. A valid Screaming Frog license. The free version has a 500-URL crawl limit. Most MCP features (headless CLI, saving/loading crawls, exports) require a paid license.

3. Python 3.10+

Important: How the Workflow Works

Screaming Frog uses an internal database that can only be accessed by one process at a time. This means:

You must close the Screaming Frog GUI before the MCP server can access crawl data.

The typical workflow is:

1. Run your crawl — either through the SF GUI (with all your custom settings, filters, etc.) or via the MCP crawl_site tool.
2. Close the Screaming Frog GUI — the GUI locks the crawl database. The MCP server's headless CLI cannot read or export data while the GUI is running.
3. Use the MCP tools — once the GUI is closed, you can list crawls, export data, read CSVs, and more through your AI assistant.

If you forget to close the GUI, the server will detect it and show a clear error message telling you to quit SF first.

Setup

Option A: Install from PyPI (recommended)

Install as a persistent uv tool so the server starts instantly:

uv tool install screaming-frog-mcp

This puts a screaming-frog-mcp executable on your PATH (typically ~/.local/bin/screaming-frog-mcp). Update later with uv tool upgrade screaming-frog-mcp.

Alternatively, install with pip:

pip install screaming-frog-mcp

Avoid uvx screaming-frog-mcp in MCP client configs. uvx resolves and downloads the package environment at launch — on a cold cache this can exceed the client's 60-second initialize timeout, causing intermittent "Could not attach to MCP server" errors. A persistent install never touches the network at startup.

Option B: Clone and install from source

git clone https://github.com/bzsasson/screaming-frog-mcp.git
cd screaming-frog-mcp
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Configure the CLI path

The default Screaming Frog CLI path works for macOS. If you're on Linux or Windows, set the SF_CLI_PATH environment variable:

If you cloned the repo, copy .env.example to .env and edit it.

Add to Claude Code

If installed via uv tool install or pip:

{
  "mcpServers": {
    "screaming-frog": {
      "command": "/path/to/screaming-frog-mcp",
      "args": [],
      "env": {
        "SF_CLI_PATH": "/path/to/ScreamingFrogSEOSpiderLauncher"
      }
    }
  }
}

Find the executable path with which screaming-frog-mcp (e.g. ~/.local/bin/screaming-frog-mcp for uv tool installs). Use the full absolute path — GUI apps don't inherit your shell's PATH.

If cloned from source:

{
  "mcpServers": {
    "screaming-frog": {
      "command": "/path/to/screaming-frog-mcp/.venv/bin/python",
      "args": ["/path/to/screaming-frog-mcp/sf_mcp.py"]
    }
  }
}

Add to Claude Desktop

Add to your Claude Desktop config (claude_desktop_config.json), using the same absolute executable path:

{
  "mcpServers": {
    "screaming-frog": {
      "command": "/path/to/screaming-frog-mcp",
      "args": [],
      "env": {
        "SF_CLI_PATH": "/path/to/ScreamingFrogSEOSpiderLauncher"
      }
    }
  }
}

Restart Claude Desktop after editing the config.

Available Tools

Usage Examples

Check installation

"Is Screaming Frog installed and licensed?"

The assistant will call sf_check and report version/license info.

Work with existing crawls (recommended flow)

For most use cases, crawl in the Screaming Frog GUI where you have full control over configuration, JavaScript rendering, crawl scope, custom extraction, etc. Then close the GUI and use the MCP to analyze the results:

After you've crawled a site in the Screaming Frog GUI and closed it:

"List my saved crawls" "Export the crawl for example.com" "Show me all pages with missing meta descriptions" "What are the 404 pages?"

Crawl a site via MCP (optional)

"Crawl https://example.com"

The crawl_site tool can kick off headless crawls via CLI. This is useful for quick re-crawls or automated workflows, but note the limitations compared to the GUI:

• Uses default crawl settings (no custom extraction, JavaScript rendering config, etc.)
• You can pass a .seospiderconfig file to customize settings (including crawl URL limits), but the GUI is easier for complex setups
• The crawl must finish and save before you can export data

Export options

The server supports all of Screaming Frog's export tabs, bulk exports, and reports. Ask the assistant to read the screaming-frog://export-reference resource for the full list, or specify them directly:

export_tabs: "Internal:All,Response Codes:All,Page Titles:All"
bulk_export: "All Inlinks,All Outlinks"
save_report: "Crawl Overview"

Configuration

Environment variables

Filtering modes

read_crawl_data supports three filter modes via the filter_mode parameter:

Temp file cleanup

Exported CSVs are stored in ~/.cache/sf-mcp/exports/ and are automatically cleaned up after 1 hour (configurable via SF_EXPORT_TTL_SECONDS).

Troubleshooting

Server won't connect at all? ("Could not attach to MCP server", "failed to connect") — see TROUBLESHOOTING.md for a step-by-step diagnostic guide: testing the server manually, verifying the MCP handshake, and finding your client's logs.

License

MIT