wp-filesystem-api

What problem does it solve?

This Skill prevents broken plugin file writes on shared hosting by using WordPress' WP_Filesystem abstraction instead of direct PHP filesystem calls that may fail when the web user lacks permissions.

Core Features & Use Cases

• When to use this Skill: writing outside wp-content/uploads (generated CSS/cache/logs/exports), handling hosts that require FTP/SSH for file operations, and any scenario where WP administrators may be prompted for filesystem credentials.
• Bootstrap flow: loads wp-admin/includes/file.php, runs request_filesystem_credentials() to obtain credentials (or trigger the credential form), then initializes WP_Filesystem() and uses the global $wp_filesystem instance.
• Transport selection & constants: explains direct/ssh2/ftpext/ftpsockets selection via get_filesystem_method(), including FS_METHOD, FS_CHMOD_FILE, and FS_CHMOD_DIR for correct permissions.
• Correct method usage: covers the key read/write/delete operations (exists/is_file/get_contents/put_contents/mkdir/copy/delete, etc.) and how to pass chmod constants for consistent behavior.
• Guardrails: clarifies what NOT to use (uploads pipeline uses wp_handle_upload/media_handle_upload; reads can be plain PHP; avoid WP_Filesystem in REST/AJAX/cron unless you explicitly handle transport gating).

Quick Start

Use the wp-filesystem-api skill when your WordPress plugin needs to write files outside uploads but shared hosting may require an FTP/SSH credentials prompt.