smalltalk-validator-mcp-server

A simple MCP server for validating and linting Tonel formatted Smalltalk source code using tree-sitter-tonel-smalltalk.

• The purpose is that we would like to validate and lint AI-generated tonel files and Smalltalk method definitions before loading them into a real Smalltalk environment.

Tools

Validation Tools

validate_tonel_smalltalk_from_file(file_path, options)

• Validate Tonel formatted Smalltalk source code from a file

validate_tonel_smalltalk(file_content, options)

• Validate Tonel formatted Smalltalk source code from content string

validate_smalltalk_method_body(method_body_content)

• Validate a Smalltalk method body for syntax correctness

Validation Options

without-method-body: true
    if true, it only validates tonel structure only (mainly for testing)

Linting Tools

lint_tonel_smalltalk_from_file(file_path)

• Lint Tonel formatted Smalltalk source code from a file

lint_tonel_smalltalk(file_content)

• Lint Tonel formatted Smalltalk source code from content string

See docs/lint-checks.md for the full list of checks.

Installation

Quick install (uvx)

Run directly without cloning:

uvx --from git+https://github.com/mumez/smalltalk-validator-mcp-server.git@main smalltalk-validator-mcp-server

Development setup (git clone)

git clone https://github.com/mumez/smalltalk-validator-mcp-server.git
cd smalltalk-validator-mcp-server
uv sync

Usage

Running the MCP Server

• Using uvx (recommended for quick run):

uvx --from git+https://github.com/mumez/smalltalk-validator-mcp-server.git@main smalltalk-validator-mcp-server

• From a cloned repo:

uv run smalltalk-validator-mcp-server

Configuration Examples

Cursor Configuration

Add to your .cursor/settings.json:

{
  "mcpServers": {
    "smalltalk-validator": {
      "command": "uvx",
      "args": [
        "--from",
        "git+https://github.com/mumez/smalltalk-validator-mcp-server.git@main",
        "smalltalk-validator-mcp-server"
      ]
    }
  }
}

If you prefer using a local clone, use this instead:

{
  "mcpServers": {
    "smalltalk-validator": {
      "command": "uv",
      "args": [
        "--directory",
        "/path/to/smalltalk-validator-mcp-server",
        "run",
        "smalltalk-validator-mcp-server"
      ]
    }
  }
}

Claude Code Configuration

Add to your Claude Code settings:

claude mcp add smalltalk-validator -- uvx --from git+https://github.com/mumez/smalltalk-validator-mcp-server.git@main smalltalk-validator-mcp-server

Using a local clone instead:

claude mcp add smalltalk-validator -- uv --directory /path/to/smalltalk-validator-mcp-server run smalltalk-validator-mcp-server

Tool Usage Examples

Validate Tonel file from filesystem

# Validate a complete Tonel file with method bodies
validate_tonel_smalltalk_from_file("/path/to/MyClass.st")

# Validate only Tonel structure (without method body validation)
validate_tonel_smalltalk_from_file("/path/to/MyClass.st", {"without-method-body": true})

Validate Tonel content directly

tonel_content = """
Class {
    #name : #MyClass,
    #superclass : #Object,
    #category : #'My-Package'
}

{ #category : #accessing }
MyClass >> getValue [
    ^ 42
]
"""

validate_tonel_smalltalk(tonel_content)

Validate Smalltalk method body

method_body = "^ self name asUppercase"
validate_smalltalk_method_body(method_body)

Lint Tonel file from filesystem

# Lint a Tonel file for best practices and style issues
result = lint_tonel_smalltalk_from_file("/path/to/MyClass.st")

# Example result:
# {
#   "success": true,
#   "file_path": "/path/to/MyClass.st",
#   "issue_list": [
#     {
#       "severity": "warning",
#       "message": "Method 'longMethod' long: 18 lines (recommended: 15)",
#       "class_name": "MyClass",
#       "selector": "longMethod",
#       "is_class_method": false
#     }
#   ],
#   "issues_count": 1,
#   "warnings_count": 0,
#   "errors_count": 0
# }

Lint Tonel content directly

tonel_content = """
Class {
    #name : #MyClass,
    #superclass : #Object,
    #instVars : [
        'name',
        'age'
    ],
    #category : #'My-Package'
}

{ #category : #accessing }
MyClass >> getName [
    ^ name
]
"""

result = lint_tonel_smalltalk(tonel_content)

Development

# Install dependencies
uv sync

# Run tests
uv run pytest

# Lint and format
uv run ruff check
uv run ruff format

# Install pre-commit hooks
uv run pre-commit install