Ziplore: US ZIP to county, FIPS, time zone, Census demographics; radius and city ZIPs. Free, no key.
Streamable HTTP
https://ziplore.cybermaxtools.com/mcp?via=mcp-registryclaude mcp add --transport http ziplore https://ziplore.cybermaxtools.com/mcp?via=mcp-registryThis server publishes no installable package.