MCP Expr-Lang provides a seamless integration between Claude AI and the powerful expr-lang expression evaluation engine.
A powerful expression evaluation tool for Claude Desktop using the Model Context Protocol (MCP).
MCP Expr-Lang provides a seamless integration between Claude AI and the powerful expr-lang expression evaluation engine. This tool allows you to perform complex data manipulations, calculations, and transformations directly within your Claude conversations.
With MCP Expr-Lang, you can:
To install MCP Expr-Lang for Claude Desktop automatically via Smithery:
npx -y @smithery/cli install @ivan-saorin/mcp-expr-lang --client claude
git clone https://github.com/ivan-saorin/mcp-expr-lang.git
cd mcp-expr-lang
go mod download
go build -o bin/server.exe
go build -o bin/server
chmod +x bin/server
config.json
:{
"mcpServers": {
"eval": {
"command": "C:\\path\\to\\mcp-expr-lang\\bin\\server.exe"
}
}
}
{
"mcpServers": {
"eval": {
"command": "/path/to/mcp-expr-lang/bin/server"
}
}
}
Once installed, you can use the eval
tool directly in your conversations with Claude. Simply ask Claude to evaluate an expression using the tool.
User: Use eval to calculate "10 + 5 * 3"
Claude: [Uses eval tool]
Result: 10 + 5 * 3 = 25
User: We have users = [{"Name": "John", "Age": 30},{"Name": "Ivan", "Age": 51},{"Name": "Eve", "Age": 15}]
Use eval to calculate "sortBy(users, .Age, "desc")"
Claude: [Uses eval tool]
Result: The expression returns the users sorted by age in descending order:
[
{"Age": 51, "Name": "Ivan"},
{"Age": 30, "Name": "John"},
{"Age": 15, "Name": "Eve"}
]
For more examples please see EXAMPLES
MCP Expr-Lang supports all features of the expr-lang engine, including:
For a complete guide to the expression language syntax and capabilities, see the expr-lang documentation.
Tool not appearing in Claude: Make sure the path in your config.json
is correct and Claude Desktop has been restarted.
Execution errors: Check that the expression syntax is correct according to the expr-lang documentation.
Permission issues (macOS/Linux): Ensure the server binary has execution permissions (chmod +x bin/server
).
If you encounter any issues or have questions:
Contributions are welcome! If you'd like to improve MCP Expr-Lang:
git checkout -b feature/amazing-feature
)git commit -m 'Add some amazing feature'
)git push origin feature/amazing-feature
)This project is licensed under the MIT License - see the LICENSE file for details.
Made with ❤️ by Ivan Saorin
Assists AI developers with requirement clarification, module design, and technical architecture.
An MCP server for interacting with the Postman API, requiring an API key.
Arbitrary code execution and tool-use platform for LLMs by Riza
A Ruby gem for integrating Large Language Models (LLMs) via the Model Context Protocol (MCP) into development workflows.
Advanced code search and transformation powered by ugrep and ast-grep for modern development workflows.
Provides LLMs with essential random generation abilities, built entirely on Python's standard library.
Introspects Laravel codebases to provide structured information about views, routes, classes, and models using the mateffy/laravel-introspect package.
Official MCP server for Buildable AI-powered development platform. Enables AI assistants to manage tasks, track progress, get project context, and collaborate with humans on software projects.
An MCP server for AI coding assistants to control, inspect, and modify Bevy applications using the Bevy Remote Protocol (BRP).
Navigate your OpenTelemetry resources, investigate incidents and query metrics, logs and traces on Dash0.