Side-by-side comparison of two Model Context Protocol servers — install paths, tools, quality signals, and directory engagement so you can pick the right one for Claude, Cursor, and other MCP clients.
Chemistry toolbox computed from authoritative data: molecular weight / molar mass of any formula (nested groups, isotope labels, propagated NIST uncertainties, percent composition), isotope-distribution mass spectra (m/z peaks for a given charge), and name⇆formula lookup with isomer resolution. Element masses from the NIST Atomic Weights and Isotopic Compositions database; offline and deterministic, with an optional on-by-default online fallback (PubChem/Wikidata/EPA CompTox) that can be disabled. uvx mcp-molecules.
MCP server for SPARKIT, a scientific research agent that searches the literature, reads papers, and returns cited Markdown reports. Submit a question via the research tool from Claude Desktop / Cursor / Claude Code; get back a 90-second cited report without leaving the chat. uv tool install sparkit-mcp or pip install sparkit-mcp.