#XQuery MCP Server

An MCP server that gives AI agents access to XQuery spec reference and the PhoenixmlDb XQuery engine. Look up expressions, functions, and error codes. Validate and execute queries.

#Install

#Self-contained binary (no .NET required)

Download from GitHub Releases:

#.NET tool

dotnet tool install -g xquery-mcp
                          

#Configure

#Claude Code

Add to .mcp.json in your project root:

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

#Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "xquery": {
      "command": "xquery-mcp",
      "args": []
    }
  }
}
                          

#Tools

#Spec Reference

• xquery_lookup_expression — Look up XQuery expressions (FLWOR, path, typeswitch, etc.)

• xquery_lookup_function — Look up XPath/XQuery functions (signature, parameters, examples)

• xquery_lookup_prolog — Look up prolog declarations (namespaces, functions, modules)

• xquery_lookup_error_code — Look up error codes with descriptions and fix suggestions

• xquery_search — Full-text search across all spec entries

• xquery_list_expressions — List all expression types

• xquery_list_functions — List all functions by category

#Execution

• xquery_evaluate — Execute an XQuery expression with optional XML input

• xquery_validate — Compile a query without executing

• xpath_evaluate — Evaluate an XPath expression against XML

• xquery_explain_error — Explain an error code with causes and fixes

#Utilities

• xml_validate_schema — Validate XML against an XSD schema

• xml_format — Pretty-print XML

#How It Works

The server bundles spec reference files covering XQuery 3.1, XPath 3.1, Functions & Operators, and the Update Facility. At startup, it loads them into an in-memory index. Lookup tools search the index; execution tools delegate to the PhoenixmlDb.XQuery engine.

#Source

github.com/phoenixmldb/xquery-mcp