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LangChain nucleus Prompt/flywheel_brief

How to: LangChain nucleus flywheel_brief

client:LangChain transport:streamable-http prompt:flywheel_brief

Add nucleus 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({
        "nucleus": {
            "transport": "streamable_http",
            "url": "https://relay.nucleusos.dev/mcp",
        }
})

tools = await client.get_tools()
  1. 02

    Save the file and restart LangChain.

  2. 03

    flywheel_brief is surfaced through the client's prompt API, fetched by name. Unlike a tool, you invoke it deliberately — LangChain will not call it for you.

  3. 04

    If it does not appear, check that nucleus is connected and that you are looking at its prompts rather than its tools.

get_tools() returns the server's tools as LangChain tools, ready for an agent. LangChain docs

Set these first

nucleus will not start until these are set, so it never reaches LangChain.

  • NUCLEUS_BRAIN_PATH

Same prompt, other clients

Read from the server itself, by connecting to it and calling prompts/list on 24 September 2026. A listing does not declare its prompts, so asking is the only way to know them, and this is what the server actually offers rather than what its listing claims. Names only are stored; connect the server for each prompt's arguments.