LangChain geonames-mcp-server geonames_find_postal_codes
How to: LangChain geonames-mcp-server geonames_find_postal_codes
Add geonames-mcp-server to LangChain
-
01
Open pip install langchain-mcp-adapters and merge this in. Keep any servers already there.
from langchain_mcp_adapters.client import MultiServerMCPClient
client = MultiServerMCPClient({
"geonames-mcp-server": {
"transport": "streamable_http",
"url": "https://geonames.caseyjhand.com/mcp",
}
})
tools = await client.get_tools()
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02
Save the file and restart LangChain.
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03
Ask for something geonames_find_postal_codes does. LangChain lists the server's tools on connect and calls geonames_find_postal_codes itself — you do not invoke it by name.
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04
If nothing happens, check the server is running and that geonames-mcp-server's identifier in your config matches the one above exactly.
get_tools() returns the server's tools as LangChain tools, ready for an agent. LangChain docs
Set these first
geonames-mcp-server will not start until these are set, so geonames_find_postal_codes never becomes available.
-
GEONAMES_USERNAME -
MCP_LOG_LEVEL
Same tool, other clients
This list was read from the server itself, by connecting to it and calling tools/list on 2 October 2026. It is what
the server actually exposes, not what its listing claims.
Mutating and Read-only are read off each tool's name, not its schema — a hint, not a guarantee. The registry stores tool names only; connect the server for its live schemas.