---
id: mhattingpete/claude-skills-marketplace/code-transfer
version: "c8216811"
license: Apache-2.0
install: manual
updated: 2026-07-25
---

# code-transfer — Code Transfer handles moving code blocks between files with exact line-number control. Choose between basic mode for small operations or execution mode for batch transfers across many files. Perfect for reorganizing functions, extracting classes, or inserting code at specific locations.

Publisher: mhattingpete · Stars: 657 · Updated: 2026-07-25

Install (manual): `git clone https://github.com/mhattingpete/claude-skills-marketplace`

## SKILL.md

# Code Transfer

Transfer code between files with precise line-based control. **Dual-mode operation**: native tools (1-10 files) or execution mode (10+ files, 90% token savings).

## Operation Modes

### Basic Mode (Default)
Use Read, Edit, Bash scripts for 1-10 file operations. Works immediately, no setup required.

### Execution Mode (10+ files)
```python
from api.filesystem import batch_copy
from api.code_analysis import find_functions

functions = find_functions('app.py', pattern='handle_.*')
operations = [{
    'source_file': 'app.py',
    'start_line': f['start_line'],
    'end_line': f['end_line'],
    'target_file': 'handlers.py',
    'target_line': -1
} for f in functions]
batch_copy(operations)
```

## When to Use

- "copy this code to [file]"
- "move [function/class] to [file]"
- "extract this to a new file"
- "insert at line [number]"
- "reorganize into separate files"

## Core Operations

### 1. Extract Source Code
```
Read(file_path="src/auth.py")                              # Full file
Read(file_path="src/auth.py", offset=10, limit=20)         # Line range
Grep(pattern="def authenticate", -n=true, -A=10)           # Find function
```

### 2. Insert at Specific Line
Use `line_insert.py` script for line-based insertion:

```bash
python3 skills/code-transfer/scripts/line_insert.py <file> <line_number> <code> [--backup]
```

**Examples:**
```bash
# Insert function at line 50
python3 skills/code-transfer/scripts/line_insert.py src/utils.py 50 "def helper():\n    pass"

# Insert with backup
python3 skills/code-transfer/scripts/line_insert.py src/utils.py 50 "code" --backup

# Insert at beginning
python3 skills/code-transfer/scripts/line_insert.py src/new.py 1 "import os"
```

**When to use:**
- User specifies exact line number
- Inserting into new/empty files
- Inserting at beginning/end without context

### 3. Insert Relative to Content
Use **Edit** when insertion point is relative to existing code:

```
Edit(
  file_path="src/utils.py",
  old_string="def existing():\n    pass",
  new_string="def existing():\n    pass\n\ndef new():\n    return True"
)
```

## Workflow Examples

### Copy Function Between Files
1. Find: `Grep(pattern="def validate_user", -n=true, -A=20)`
2. Extract: `Read(file_path="auth.py", offset=45, limit=15)`
3. Check target: `Read(file_path="validators.py")`
4. Insert: Use `line_insert.py` or Edit based on context

### Extract Class to New File
1. Locate: `Grep(pattern="class DatabaseConnection", -n=true, -A=50)`
2. Extract: `Read(file_path="original.py", offset=100, limit=50)`
3. Create: `Write(file_path="database.py", content="<extracted>")`
4. Update imports: `Edit` in original file
5. Remove old class: `Edit` with replacement

### Insert at Specific Line
1. Validate: `Read(file_path="main.py", offset=20, limit=10)`
2. Insert: `python3 skills/code-transfer/scripts/line_insert.py main.py 25 "logger.info('...')" --backup`
3. Verify: `Read(file_path="main.py", offset=23, limit=5)`

### Reorganize Into Modules
1. Analyze: `Read(file_path="utils.py")`
2. Identify groups: `Grep(pattern="^def |^class ", -n=true)`
3. Extract each category: `Write` new files
4. Update original: Re-export or redirect

## Best Practices

**Planning:**
- Understand dependencies (imports, references)
- Identify exact start/end of code block
- Check target file structure
- Ensure necessary imports included

**Preservation:**
- Include docstrings and comments
- Transfer related functions together
- Update imports in both files
- Maintain formatting/indentation

**Validation:**
- Verify insertion placement
- Check syntax
- Test imports
- Suggest running tests

**Backups:**
- Use `--backup` for significant changes
- Critical file operations
- Large deletions

## Integration

- **code-refactor**: Refactor after transferring
- **test-fixing**: Run tests after reorganizing
- **feature-planning**: Plan large reorganizations


[View on SkillFed](https://skillfed.io/mhattingpete/claude-skills-marketplace/code-transfer) · [View on GitHub](https://github.com/mhattingpete/claude-skills-marketplace)