LangChain — Python Tools

The DPX LangChain tools let any Python agent price settlements, check stability, and retrieve ESG scores using the standard @tool decorator pattern.

Installation

pip install langchain langchain-openai httpx

Tool file

/Users/victoriacase/Documents/GitHub/dpx-protocol/dpx-agents/langchain_tools.py

Available tools

Tool	Description
dpx_get_manifest	Protocol capabilities and contract addresses
dpx_get_quote	Full fee breakdown for a settlement
dpx_get_esg_score	Live E, S, G scores
dpx_get_reliability	Stability signals
dpx_verify_fees	On-chain fee verification
dpx_get_fee_schedule	Complete fee table
dpx_compare_fees	DPX vs Stripe, Wise, SWIFT

Usage

from langchain_tools import dpx_tools
from langchain_openai import ChatOpenAI
from langchain.agents import create_tool_calling_agent, AgentExecutor

llm = ChatOpenAI(model="gpt-4o")
agent = create_tool_calling_agent(llm, dpx_tools, prompt)
executor = AgentExecutor(agent=agent, tools=dpx_tools)

result = executor.invoke({
    "input": "Price a $2M cross-border settlement with ESG score 75"
})

MCP adapter (recommended for production)

For production LangChain deployments, use the MCP adapter instead of direct HTTP tools. This gives you automatic schema updates whenever the protocol changes.

from langchain_mcp_adapters.client import MultiServerMCPClient

client = MultiServerMCPClient({
    "dpx": {
        "command": "node",
        "args": ["/path/to/dpx-mcp/index.js"],
        "transport": "stdio"
    }
})

tools = await client.get_tools()

Environment

STABILITY_ORACLE_URL=http://localhost:3000
ESG_ORACLE_URL=http://localhost:3001

Beta partners: Replace the localhost URLs with the production endpoints provided upon approval.