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LangChain Date Math date_range

How to: LangChain Date Math date_range

client:LangChain transport:streamable-http tool:date_range

Add Date Math to LangChain

  1. 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({
        "date-math": {
            "transport": "streamable_http",
            "url": "https://date-math.datemath.workers.dev/mcp",
        }
})

tools = await client.get_tools()
  1. 02

    Save the file and restart LangChain.

  2. 03

    Ask for something date_range does. LangChain lists the server's tools on connect and calls date_range itself — you do not invoke it by name.

  3. 04

    If nothing happens, check the server is running and that Date Math'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

Date Math will not start until these are set, so date_range never becomes available.

  • DATE_MATH_PRIVATE_KEY
  • DATE_MATH_MAX_PRICE

Same tool, other clients

This list was read from the server itself, by connecting to it and calling tools/list on 14 November 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.