The Catalysis Hub MCP Server provides a Model Context Protocol interface to Catalysis Hub's GraphQL API, enabling programmatic access to catalysis research data through flexible GraphQL queries. It exposes comprehensive data domains including catalytic reactions (equations, conditions, catalysts), material systems (structures, properties, descriptors), research publications (titles, DOIs, authors), and surface reaction data (adsorption energies, binding sites). The server is MCP standard–compliant, designed for AI-agent interoperability, and supports parameterized queries with variables for dynamic querying. It emphasizes robust error handling and clear diagnostics for connectivity and query failures. Implementation relies on the httpx asynchronous HTTP client and uses standard MCP transport over standard input/output. Server configuration mirrors claude_desktop_config.json to facilitate seamless integration within Claude-based environments. Setup involves cloning the repository, installing dependencies, and verifying installation with a version check that prints catalysishub-mcp-server 0.1.0. Usage examples demonstrate how to issue GraphQL queries via the MCP client, including parameterized queries that fetch systems, reactions, and related data. The repository also provides guidance on query optimization and troubleshooting to help users build efficient queries against the Catalysis Hub database.