What is mcp-molecules?
mcp-molecules is a MCP server by laszlopere that chemistry tools from NIST data: molar mass with uncertainties, isotope-distribution mass spectra and name-formula lookup, offline or with online fallback. It is listed under Knowledge & memory and has 1 GitHub stars.
| Type | Mcp server |
|---|---|
| Author | laszlopere |
| Repository | laszlopere/mcp-molecules |
| Popularity | 1 GitHub stars |
| Category | Knowledge & memory |
| Security | Low risk (84/100) |
| Rank | #3,535 of 4,418 MCP servers; #378 in Knowledge & memory |
| License | GPL-3.0 |
| Last commit | 2026-10-13 |
| Runs | Locally and in the cloud |
| Language | Python |
| Platforms | macOS, Linux |
Is mcp-molecules safe to install?
mcp-molecules scores 84/100 on the MCPMods security check: Low risk. Things to review: sends your data to a cloud service. It passed 4 of 6 checks.
MCP server results come from listing signals: who publishes it, where your data goes and what it can do. The code itself is not scanned yet.
| Check | Result |
|---|---|
| Community-built server | Note |
| Sends your data to a cloud service | Review |
| No credentials mentioned | Pass |
| Read-only by description | Pass |
| No code execution | Pass |
| Source on GitHub | Pass |
How do I install mcp-molecules?
- Find the launch command. The README says how the server starts (npx, uvx, docker or a remote URL) and which API keys it needs.
https://github.com/laszlopere/mcp-molecules
- Add it to Claude Code. Replace the part after -- with the command from the README. Remote servers use --transport http with a URL.
claude mcp add mcp-molecules -- <command from README> claude mcp add --transport http mcp-molecules <server-url>
- Check it connected. This lists your MCP servers and their status.
claude mcp list
Or ask Claude to set it up
Paste this into Claude Code and it installs mcp-molecules for you:
Add the "mcp-molecules" MCP server from https://github.com/laszlopere/mcp-molecules to Claude Code. Read its README for the launch command and any API keys I need, run claude mcp add, then check that it connects.