Webarchive Agent Skill

The user wants to extract a .webarchive file using WebArchiveExtractor.

If arguments were provided ($ARGUMENTS), use them to infer the input file and optionally the output directory or URL prepend. Otherwise, ask the user for the path to the .webarchive file.

How to run WebArchiveExtractor

/Applications/WebArchiveExtractor.app/Contents/MacOS/WebArchiveExtractor [-h] [-o <OutputDirectory>] [-p <URLPrepend>] -i <WebArchiveFile>

Options:

• -i <WebArchiveFile> — required — path to the .webarchive file
• -o <OutputDirectory> — directory to write extracted files into (optional; defaults to a directory named after the archive next to it)
• -p <URLPrepend> — URI prefix to prepend to all asset URLs in the extracted HTML (optional; useful when serving the result from a subdirectory)

Shorthand (no flag):

WebArchiveExtractor website.webarchive

A positional argument is treated as the -i value.

Prerequisites

The app must be installed at /Applications/WebArchiveExtractor.app. Check with:

test -x /Applications/WebArchiveExtractor.app/Contents/MacOS/WebArchiveExtractor && echo "found" || echo "not installed"

If not found, tell the user to build and install from source (xcodebuild -project WebArchiveExtractor.xcodeproj) or drag a release build to /Applications.

To use WebArchiveExtractor without the full path, the user can add it to PATH:

export PATH="$PATH:/Applications/WebArchiveExtractor.app/Contents/MacOS/"

Or create a symlink:

ln -s /Applications/WebArchiveExtractor.app/Contents/MacOS/WebArchiveExtractor ~/.local/bin/WebArchiveExtractor

Steps

• Check the binary exists using the test command above. If not found, stop and direct the user to install the app.
• Determine the input .webarchive file from $ARGUMENTS or ask the user.
• Determine the output directory:
• If the user explicitly provided one in $ARGUMENTS, use that.
• Otherwise, default to ~/Downloads/<archive-name> (where <archive-name> is the input filename without the .webarchive extension).
• If the user asks why ~/Downloads is the default, explain: macOS sandboxes the WebArchiveExtractor app, which restricts which directories the CLI can write to. The ~/Downloads folder is one of the few locations reliably accessible, so it's used as the default to avoid silent failures.
• Determine (optional) URL prepend from $ARGUMENTS or ask if needed.
• Run the extractor using the Bash tool:

   /Applications/WebArchiveExtractor.app/Contents/MacOS/WebArchiveExtractor -i "<input>" -o "<output>" [-p "<prepend>"]

• If successful, list the output directory contents with ls and summarise:
• The output directory path
• How many files were extracted
• The main HTML file name (if identifiable)
• Offer to open the extracted HTML in the browser with open <file>.

Notes

• .webarchive is a macOS-specific binary plist format used by Safari's "Save As Web Archive" feature.
• The CLI and the GUI app are the same binary — running with -i suppresses the GUI.
• Running with no arguments launches the GUI instead of extracting anything.