DCP-AI + LangChain Template

A walkthrough of the DCP flow around a LangChain call.

A walkthrough, not a signer. The keys and signatures in index.js are placeholders («generated», «sig»): the template shows the shape of the DCP v2.0 flow, but it generates no keys, signs nothing, and its bundles do not verify. It reads nothing from .dcp/. For real keys and signatures, follow docs/QUICKSTART_LANGCHAIN.md.

The template pins LangChain.js 0.3 (langchain and @langchain/openai ^0.3.0); the guide shows the current LangChain.js v1 API.

Quick Start

1. Install dependencies:

   npm install
   

2. Run it. With OPENAI_API_KEY the template calls the OpenAI API (billed by OpenAI). If the call fails for any reason (no key, network, quota, model), it prints a simulated response and still records outcome: "success", so the audit entry does not show that the call succeeded. Set the key in your environment:

   node index.js
   

What this template does

• Wraps a LangChain call in the DCP flow
• Every action is declared as an Intent; the policy step is a stub that always returns approve (risk 50), so the escalate and block branches show the flow but are not reached
• Every response gets an audit entry
• The agent's Citizenship Bundle carries placeholder signatures

Files

• index.js — LangChain call with the DCP flow
• package.json — Dependencies