Web Algebra MCP server

Web-Algebra

<!-- mcp-name: io.github.AtomGraph/web-algebra -->

A composable RDF operations system that translates natural language instructions into JSON-formatted domain-specific language operations for loading, querying, and writing RDF Linked Data.

Overview

This system implements generic operations for RDF Linked Data and SPARQL management, as well as some LinkedDataHub-specific operations. Operations can be consumed in two ways:

1. Executable JSON format: Operations are composed into JSON structures and executed by the provided execution engine
2. Model Context Protocol (MCP): Operations are exposed as tools for AI agents to use interactively

Instead of agents executing semantic workflows step-by-step through individual MCP tool calls, Web-Algebra enables agents to compile entire workflows into optimized JSON "bytecode" that executes atomically - enabling complex multi-operation compositions.

Demo

See WebAlgebra in action - translating natural language into RDF operations.

Architecture

The system is built around the Operation abstract base class that provides:

• Registry System: Auto-discovery of operations from src/web_algebra/operations/
• JSON DSL: Operations use @op key with args for parameters, supporting nested operation calls
• RDFLib Type System: Uses URIRef, Literal, Graph, and Result types internally for proper RDF handling
• Execution Engine: Both standalone execution and MCP server integration
• Context System: ForEach operations set row context for inner operations to access via Value
• URI Resolution: Proper semantic URI construction with ResolveURI operation

Key Components

• System Prompt: Complete operation definitions and JSON format specification
• Formal Semantics: Complete type system and operation catalog
• Operation Interface: Base class and JSON interpreter
• Operation Implementations: Directory containing all available operations
• Examples: Real-world plans over live Linked Data, each with its result and checks

Operations

The operations cover read-write Linked Data, SPARQL queries, URI manipulation, and LinkedDataHub-specific resource creation. Non-exhaustive list:

• Linked Data
• GET
• PATCH
• POST
• PUT
• SPARQL
• CONSTRUCT
• DESCRIBE
• SELECT
• Substitute
• Values
• SPARQLString

Usage

Pre-requisites

uv venv uv sync

1. Install uv
2. bash

### Standalone

#### Natural language instruction

uv run python src/web_algebra/main.py

Shortened. The full README is on GitHub.