A Model Context Protocol Server for Astrophysical RAG: Unified Access to HI, Dwarf, Globular Cluster, IntZ, and ALPINE Kinematic Corpora with FAISS Semantic Search

We present the EPS Research Astro-RAG MCP Server v2.3.0, a cross-platform Model Context Protocol (MCP) implementation providing unified, machine-readable access to five astrophysical corpora spanning the local universe (z = 0) to z = 5.68 (the high-redshift frontier of the ALPINE survey). The server exposes a humanreadable browser query interface, a REST API, and an LLM-native MCP endpoint, enabling deterministic retrieval, metadata filtering, and structured analysis across 2,064 objects: galaxies spanning HI rotation curve surveys, dwarf and irregular systems, and high-redshift kinematic targets, together with Milky Way globular clusters. Version 2.3.0 introduces FAISS-accelerated natural-language similarity search using pre-built 384-dimensional MiniLM-L6-v2 vector indexes, enabling corpus-wide semantic queries without fine-tuning or API keys. We describe the server architecture, unified schema design, FAISS index construction pipeline, MCP toolset, and cross-epoch use cases including rotation-curve retrieval, metadata filtering, and semantic similarity exploration. The server is publicly deployed on HuggingFace Spaces (https://dflynn5656-astro-rag-mcp.hf.space), released under the MIT License, and fully reproducible from Zenodo (DOI: 10.5281/zenodo.21154451). The full platform is available at https://github.com/eps-research/rag-corpus-series.