v1.1.0 to v1.1.1

---

name: filesystem

description:

'File and directory operations using Claude Code built-in tools — replaces

the Filesystem MCP server. Maps all 11 MCP tools to native equivalents: Read, Write,

Edit, Glob, Grep, and Bash. Covers file reading with line ranges, parallel reads,

pattern-based file search, regex content search, directory listing, tree traversal,

move/copy/rename, and metadata inspection. Trigger phrases: "read this file", "write

to file", "create a file", "edit file", "find files matching", "search for text

in files", "list directory", "show directory tree", "move file", "rename file",

"copy file", "file info", "find all Python files", "search codebase for". Use this

skill when performing file operations, navigating codebases, or managing directories.

'

metadata:

category: content

tags: [files, directories, search, navigation]

difficulty: beginner

---

# Filesystem

All file and directory operations use Claude Code's built-in tools. No MCP server

needed — native tools are faster, more capable, and cost zero context tokens when idle.

## Quick Reference

| Filesystem MCP Tool | Replacement | Notes |

| ----------------------------- | ------------------------------ | ---------------------------------------------------------------------- |

| `read_file(path)` | `Read` tool | Supports line offset and limit |

| `read_multiple_files(paths)` | Multiple parallel `Read` calls | Faster than sequential MCP calls |

| `write_file(path, content)` | `Write` tool | Overwrites entire file |

| `edit_file(path, edits)` | `Edit` tool | Exact string replacement; surgical edits |

| `list_directory(path)` | `Glob` or `Bash ls` | Glob for patterns, ls for simple listing |

| `directory_tree(path)` | `Bash fd` or `Glob **/*` | fd is fastest; Glob for pattern filtering |

| `search_files(pattern, path)` | `Grep` tool | Full regex, file type filters, context lines |

| `create_directory(path)` | `Bash mkdir -p` | `-p` creates intermediate directories |

| `move_file(src, dst)` | `Bash mv` | Also handles renames |

| `get_file_info(path)` | `Bash stat` or `Bash ls -la` | Size, permissions, timestamps |

| `list_allowed_directories` | N/A | Claude Code operates in the working directory; no sandbox restrictions |

---

## Reading Files

### Read a Single File

Use the `Read` tool with an absolute path:

```text

Read: /path/to/file.py

```

For large files, use offset and limit to read specific sections:

```text

Read: /path/to/file.py (offset: 100, limit: 50)

```

This reads 50 lines starting from line 100. Use this for files with thousands of lines

to avoid flooding context.

### Read Multiple Files in Parallel

Issue multiple `Read` calls in a single response. Claude Code executes them concurrently:

```text

Read: /path/to/file1.py

Read: /path/to/file2.py

Read: /path/to/file3.py

```

Parallel reads are faster than the MCP's `read_multiple_files` which serialized internally.

### Read Images and PDFs

The `Read` tool handles binary formats:

- **Images** (PNG, JPG, SVG): displayed visually

- **PDFs**: extracted text; use `pages: "1-5"` for large documents (max 20 pages per call)

---

## Writing and Editing Files

### Write a New File

Use the `Write` tool to create a file or overwrite an existing one:

```text

Write: /path/to/new-file.py

Content: <full file content>

```

The `Write` tool requires reading the file first if it already exists. For new files,

write directly.

### Edit an Existing File

Use the `Edit` tool for surgical modifications — replace exact string matches:

```text

Edit: /path/to/file.py

old_string: "def old_function():"

new_string: "def new_function():"

```

The `Edit` tool fails if `old_string` is not unique in the file. Provide enough

surrounding context to make the match unique, or use `replace_all: true` for

find-and-replace across the entire file.

**Prefer Edit over Write** for existing files. Edit preserves everything outside the

changed region and shows a clear diff. Write replaces the entire file.

---

## Finding Files

### By Name Pattern (Glob)

```text

Glob: **/*.py → all Python files recursively

Glob: src/**/*.ts → TypeScript files under src/

Glob: *.md → Markdown files in current directory

Glob: **/test_*.py → test files anywhere in the tree

```

Results are sorted by modification time (most recent first).

### By Content (Grep)

```text

Grep: pattern="def process_data" type="py"

Grep: pattern="TODO|FIXME" glob="*.py"

Grep: pattern="class.*Controller" output_mode="content" -C=2

```

| Grep Parameter | Purpose |

| ---------------- | -------------------------------------------------- |

| `pattern` | Regex pattern to match |

| `type` | File type filter (py, js, ts, rust, go, etc.) |

| `glob` | Glob pattern filter (`*.tsx`, `src/**/*.py`) |

| `output_mode` | `files_with_matches` (default), `content`, `count` |

| `-C`, `-A`, `-B` | Context lines: around, after, before matches |

| `-i` | Case-insensitive search |

### Directory Listing

Simple listing:

```bash

ls -la /path/to/directory

```

Recursive tree with `fd`:

```bash

fd . /path/to/directory --type f

```

Tree with depth limit:

```bash

fd . /path/to/directory --type f --max-depth 2

```

Filter by extension:

```bash

fd -e py /path/to/directory

```

---

## File Operations

### Create Directory

```bash

mkdir -p /path/to/new/directory

```

The `-p` flag creates all intermediate directories. Always verify the parent path

exists first with `ls`.

### Move / Rename

```bash

mv /path/to/source.py /path/to/destination.py

```

Rename a file (same directory):

```bash

mv /path/to/old-name.py /path/to/new-name.py

```

Move a directory:

```bash

mv /path/to/source-dir /path/to/destination-dir

```

### Copy

```bash

cp /path/to/source.py /path/to/destination.py

cp -r /path/to/source-dir /path/to/destination-dir

```

### Delete

```bash

rm /path/to/file.py

rm -r /path/to/directory

```

Always confirm with the user before deleting files or directories.

### File Metadata

```bash

stat /path/to/file.py

ls -la /path/to/file.py

wc -l /path/to/file.py

```

| Command | Returns |

| -------- | ------------------------------------------- |

| `stat` | Size, permissions, timestamps, inode |

| `ls -la` | Permissions, owner, size, modification date |

| `wc -l` | Line count |

| `file` | MIME type detection |

---

## Common Workflows

### Find and Replace Across Files

```bash

# Find all files containing the old string

Grep: pattern="old_function_name" type="py" output_mode="files_with_matches"

# Then Edit each file

Edit: /path/to/file1.py (old_string → new_string, replace_all: true)

Edit: /path/to/file2.py (old_string → new_string, replace_all: true)

```

### Explore an Unfamiliar Codebase

1. Check project structure: `fd . --type f --max-depth 2`

2. Read configuration: `Read: package.json` or `Read: pyproject.toml`

3. Find entry points: `Grep: pattern="def main|if __name__" type="py"`

4. Read key files identified above

### Find Large Files

```bash

fd --type f --exec stat -f '%z %N' {} \; | sort -rn | head -20

```

---

## Error Handling

| Error | Cause | Resolution |

| --------------------------- | --------------------------------------- | ------------------------------------------------- |

| Read: file not found | Path incorrect or file deleted | Verify with `ls` or `Glob` |

| Edit: old_string not unique | Multiple matches in the file | Add more surrounding context to make it unique |

| Edit: old_string not found | Content changed since last read | Re-read the file, then retry with current content |

| Write: file not read first | Attempting to overwrite without reading | Read the file first, then Write |

| Permission denied | Insufficient OS permissions | Check with `ls -la`; use `chmod` if appropriate |

| Glob: no files found | Pattern too restrictive | Broaden the pattern; check path spelling |

---

## Limitations

- **Read** returns up to 2000 lines by default. Use offset/limit for larger files.

- **Read** truncates lines longer than 2000 characters.

- **Edit** requires exact string matching — whitespace and indentation must match precisely.

- **Write** overwrites the entire file. No append mode. To append, read first, then write

the combined content.

- **Glob** only matches files, not directories. Use `Bash ls` or `fd` to list directories.

- **PDF reading** is limited to 20 pages per call. Specify page ranges for large documents.

---

## Calibration Rules

1. **Read before Edit.** Always read a file before editing it. The Edit tool enforces this.

2. **Edit over Write for existing files.** Edit is surgical and shows diffs. Write is a

full replacement — use it only for new files or complete rewrites.

3. **Glob over Bash for file search.** Glob is optimized for pattern matching. Only fall

back to `fd` or `find` for queries Glob cannot express (size filters, date filters).

4. **Grep over Bash for content search.** Grep is optimized for ripgrep-based search with

proper permissions. Never use `grep` or `rg` via Bash.

5. **Parallel reads for multiple files.** Issue all Read calls in a single response for

concurrent execution.

6. **Always use absolute paths.** Claude Code tools require absolute paths. Never pass

relative paths to Read, Write, or Edit.