MCP SmallEdit

A Model Context Protocol (MCP) server that provides tools for making small, targeted edits to files using stream editors like sed and awk.

Why SmallEdit?

When making minor changes to files (fixing typos, updating version numbers, changing config values), using full file replacement is inefficient. SmallEdit provides targeted editing capabilities that:

• Save tokens by only specifying what to change
• Reduce errors by not rewriting entire files
• Enable bulk operations across multiple files
• Provide preview capabilities before applying changes

Installation

npm install -g @bard/mcp-smalledit

Tools Available

1. sed_edit

Make small edits using sed patterns.

Examples:

// Replace all occurrences
sed_edit({
  file: "package.json",
  pattern: "s/0.1.0/0.2.0/g"
})

// Delete lines containing pattern
sed_edit({
  file: "config.ts",
  pattern: "/DEBUG_MODE/d"
})

// Preview changes first
sed_edit({
  file: "index.ts",
  pattern: "s/foo/bar/g",
  preview: true
})

2. sed_multifile

Apply patterns to multiple files.

Examples:

// Update imports across all TypeScript files
sed_multifile({
  pattern: "s/'.\\//src\\//g",
  filePattern: "*.ts",
  directory: "src"
})

// Remove console.log from all JS files
sed_multifile({
  pattern: "/console\\.log/d",
  filePattern: "*.js"
})

3. quick_replace

Simple find and replace without regex.

Examples:

// Replace text literally
quick_replace({
  file: "README.md",
  find: "version 1.0",
  replace: "version 2.0"
})

// Replace only first occurrence
quick_replace({
  file: "config.json",
  find: "localhost",
  replace: "production.server.com",
  all: false
})

4. line_edit

Edit specific lines by number.

Examples:

// Replace line 42
line_edit({
  file: "index.ts",
  lineNumber: 42,
  action: "replace",
  content: "export const VERSION = '2.0.0';"
})

// Delete lines 10-20
line_edit({
  file: "test.ts",
  lineRange: "10,20",
  action: "delete"
})

// Insert after line 5
line_edit({
  file: "imports.ts",
  lineNumber: 5,
  action: "insert_after",
  content: "import { newModule } from './new-module';"
})

5. awk_process

Process files with AWK for complex operations.

Examples:

// Sum numbers in second column
awk_process({
  file: "data.csv",
  script: "{sum += $2} END {print sum}"
})

// Extract specific columns
awk_process({
  file: "data.tsv",
  script: "{print $1, $3}",
  outputFile: "extracted.txt"
})

Configuration

Add to your MCP client config:

{
  "mcpServers": {
    "smalledit": {
      "command": "mcp-smalledit"
    }
  }
}

Common Use Cases

Version Bumping

sed_edit({
  file: "package.json",
  pattern: 's/"version": "[^"]*"/"version": "1.2.3"/g'
})

Update Import Paths

sed_multifile({
  pattern: "s|'@old/package|'@new/package|g",
  filePattern: "*.ts"
})

Remove Debug Code

sed_multifile({
  pattern: "/\\/\\/\\s*DEBUG:/d",
  filePattern: "*.js"
})

Fix Formatting

// Add missing semicolons
sed_multifile({
  pattern: "s/^\\([^;]*\\)$/\\1;/",
  filePattern: "*.ts"
})

Safety Features

• Automatic Backups: Creates .bak files by default
• Preview Mode: Test patterns before applying
• Error Handling: Clear error messages for invalid patterns
• File Validation: Checks file existence before editing

Notes

• All file paths are relative to the current working directory
• Backup files (.bak) are created by default unless disabled
• Use preview mode to test complex patterns
• Escape special characters appropriately in patterns

License

MIT -e

Known Issues

Pattern Delimiters

When using path replacements, use pipe delimiter instead of forward slash to avoid quoting issues:

// ❌ Problematic with paths
sed_edit({ pattern: "s/old/path/new/path/g" })

// ✅ Works correctly
sed_edit({ pattern: "s|old/path|new/path|g" })