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

1. Check the binary exists using the test command above. If not found, stop and direct the user to install the app.
2. Determine the input .webarchive file from $ARGUMENTS or ask the user.
3. 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.

1. Determine (optional) URL prepend from $ARGUMENTS or ask if needed.
2. Run the extractor using the Bash tool:

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

1. 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)

1. 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.