Screaming Frog SEO Spider 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)

pip install screaming-frog-mcp

Or run directly with uvx (no install needed):

uvx screaming-frog-mcp

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:

OS	Default Path
macOS	/Applications/Screaming Frog SEO Spider.app/Contents/MacOS/ScreamingFrogSEOSpiderLauncher
Linux	/usr/bin/screamingfrogseospider
Windows	C:\Program Files (x86)\Screaming Frog SEO Spider\ScreamingFrogSEOSpiderCli.exe

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

Add to Claude Code

If installed via pip/uvx:

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

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):

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

Available Tools

Tool	Description
sf_check	Verify Screaming Frog is installed, check version and license status
crawl_site	Start a headless background crawl (see note below)
crawl_status	Check progress of a running crawl
list_crawls	List all saved crawls with their Database IDs
export_crawl	Export crawl data as CSV files (many export options available)
read_crawl_data	Read exported CSV data with pagination and filtering
delete_crawl	Permanently delete a crawl from the database
storage_summary	Show disk usage of SF's crawl storage

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

Variable	Description	Default
SF_CLI_PATH	Path to the Screaming Frog CLI executable	macOS default path
SF_ALLOWED_DOMAINS	Comma-separated list of allowed crawl target domains. When set, crawl_site only accepts URLs matching these domains.	Empty (all domains allowed)
SF_CONFIG_DIR	Directory containing .seospiderconfig files that crawl_site can load.	~/.config/sf-mcp/configs/
SF_EXPORT_TTL_SECONDS	How long exported CSV files are kept before auto-cleanup. Increase for multi-hour audit sessions.	3600 (1 hour)
SF_EXPORT_TIMEOUT_SECONDS	Max time to wait for an export_crawl operation to complete. Increase for very large crawls (100k+ URLs).	300 (5 minutes)

Filtering modes

read_crawl_data supports three filter modes via the filter_mode parameter:

Mode	Behavior	Example
contains (default)	Case-insensitive substring match	filter_value="4" matches 400, 204, 1450
exact	Case-insensitive exact match	filter_value="404" matches only 404
regex	Python regex (case-insensitive)	filter_value="^[45]" matches 4xx and 5xx

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

Problem	Solution
"GUI is already running" error	Quit the Screaming Frog application, then retry
Empty CSV exports (headers only, 0 data rows)	The GUI likely has the database locked — close it and re-export
CLI not found	Check that SF_CLI_PATH in .env points to the correct executable
Crawl not appearing in list_crawls	Make sure you saved the crawl in the GUI (File > Save) before closing
Export times out	Large crawls may need more time — set SF_EXPORT_TIMEOUT_SECONDS to a higher value (e.g. 600), or export fewer tabs
list_crawls fails on Windows	Fixed in v0.2.2 — update with uvx screaming-frog-mcp@latest or pip install -U screaming-frog-mcp

License

MIT