MCP Server around https://expr-lang.org
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{:target=“_blank”}
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{:target=“_blank”} file for details.
Made with ❤️ by Ivan Saorin
Mcp Llms Txt Explorer
MCP to explore websites with llms.txt files
Nmap Mcp Server
A Model Context Protocol (MCP) server that enables AI assistants to perform network scanning operations using NMAP
Mcp Codex Keeper
An intelligent MCP server that serves as a guardian of development knowledge, providing Cline assistants with curated access to latest documentation and best practices across the software development landscape
A open-source library enabling AI models to control hardware devices via serial communication using the MCP protocol. Initial support for Raspberry Pi Pico.
MCP server for RAG-based document search and management
MCP server providing a knowledge graph implementation with semantic search capabilities powered by Qdrant vector database