Read the contents of a file. Returns the file content and size in bytes. Errors: ENOENT if the file does not exist, EISDIR if the path is a directory.

Write content to a file, creating it if it doesn't exist. Parent directories are created automatically (mkdir -p). Overwrites existing file content entirely. Errors: EISDIR if the path is an existing directory, EINVAL if writing to root.

Append content to the end of a file. Creates the file if it doesn't exist. Parent directories are created automatically. Useful for logs or incrementally building files. The 10 MB limit is per call — total file size is not capped. Errors: EISDIR if the path is an existing directory, EINVAL if appending to root.

Check whether a path exists and get metadata about it. Returns exists (boolean), and if it exists: type (file or directory), size (bytes, for files), or children count (for directories). Never errors — returns {exists: false} for missing paths.

List the contents of a directory. Returns an array of entries, each with a name and type (file or directory). Entries are sorted with directories first, then alphabetically. Errors: ENOENT if the directory does not exist, ENOTDIR if the path is a file.

Create a directory and any missing parent directories (mkdir -p behavior). Idempotent — succeeds even if the directory already exists. Returns whether the directory already existed. Errors: EEXIST if a file (not directory) already exists at the path.

Remove a file or directory. Directories are removed recursively including all descendants. This operation is non-recoverable — there is no undo or trash. Returns the total number of nodes deleted. Errors: ENOENT if the path does not exist, EINVAL if attempting to remove root.

Move or rename a file or directory. Moves all descendants when moving a directory. Parent directories at the destination are created automatically. Errors: ENOENT if source doesn't exist, EEXIST if destination already exists, EINVAL if moving root or moving a directory into itself.

Find files matching a glob pattern. Supports wildcards (.ts), recursive matching (**/.md), and brace expansion ({py,json}). Returns an array of matching file paths. Only matches files, not directories.

Search file contents using a regular expression. Returns matching lines with file path and line number. Optimized for fast content search across all files. Optionally filter which files to search with a path glob.

List all named persistent stores. Stores are cross-session namespaces for long-term data that persists indefinitely. Returns an array of store names.