Proposition 65 is a Model Context Protocol (MCP) server: Is a chemical on California's Proposition 65 list, and does it need a warning? Because it speaks the Model Context Protocol, AI assistants can use Proposition 65 as a set of callable tools instead of you copy-pasting between apps.
You can run Proposition 65 two ways: connect to the hosted endpoint at https://prop65.toolstop.dev with no local install, or run it on your own machine via the npm package @toolstop/prop65. The current release is v0.1.0, published under the MIT license, with source at toolstop/toolstop on GitHub.
On mcp.site, Proposition 65 sits in the Cloud Service category. Any MCP client can use it — Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, Zed among them — via the install snippets below. If you maintain Proposition 65 for toolstop.dev, claim this listing to verify ownership, earn the Verified badge, and keep the details current.
