Quickstart — ZeroDev × AgentKit (LangChain chatbot)

mkdir zerodev-agentkit-bot && cd zerodev-agentkit-bot
npm init -y
 
# Core runtime deps
npm i @coinbase/agentkit @coinbase/agentkit-langchain viem @langchain/core @langchain/openai @langchain/langgraph dotenv
 
# Nice-to-have for TypeScript
npm i -D ts-node typescript @types/node

import {
  AgentKit,
  ViemWalletProvider,
  ZeroDevWalletProvider,
  NETWORK_ID_TO_VIEM_CHAIN,
  walletActionProvider,
} from "@coinbase/agentkit";
 
import { getLangChainTools } from "@coinbase/agentkit-langchain";
import { ChatOpenAI } from "@langchain/openai";
import { createReactAgent } from "@langchain/langgraph/prebuilt";
import { HumanMessage } from "@langchain/core/messages";
 
import { privateKeyToAccount } from "viem/accounts";
import { createWalletClient, http } from "viem";
 
import * as dotenv from "dotenv";
dotenv.config();
 
function mustGet(name: string) {
  const v = process.env[name];
  if (!v) throw new Error(`Missing env var ${name}`);
  return v;
}
 
async function main() {
  /* 1️⃣  Wallet setup (Viem → ZeroDev smart account) */
  const networkId = process.env.NETWORK_ID ?? "base-sepolia";
 
  const signerAccount = privateKeyToAccount(mustGet("PRIVATE_KEY") as `0x${string}`);
 
  const viemWalletProvider = new ViemWalletProvider(
    createWalletClient({
      account: signerAccount,
      chain: NETWORK_ID_TO_VIEM_CHAIN[networkId],
      transport: http(),
    }),
  );
 
  const zeroDevWalletProvider = await ZeroDevWalletProvider.configureWithWallet({
    signer: viemWalletProvider.toSigner(),
    projectId: mustGet("ZERODEV_PROJECT_ID"),
    entryPointVersion: "0.7",
    networkId,
  });
 
  /* 2️⃣  AgentKit instance */
  const agentkit = await AgentKit.from({
    walletProvider: zeroDevWalletProvider,
    actionProviders: [walletActionProvider()],
  });
 
  /* 3️⃣  LangChain agent */
  const llm = new ChatOpenAI({
    openAIApiKey: mustGet("OPENAI_API_KEY"),
    model: "gpt-4o-mini",
  });
 
  const tools = await getLangChainTools(agentkit);
 
  const lcAgent = createReactAgent({ llm, tools });
 
  console.log("Smart-account address:", zeroDevWalletProvider.getAddress());
  console.log("Ask me to do something on-chain (type ‘exit’ to quit)…\n");
 
  const rl = require("readline").createInterface({ input: process.stdin, output: process.stdout });
  for await (const line of rl) {
    const prompt = line.trim();
    if (prompt.toLowerCase() === "exit") break;
 
    const stream = await lcAgent.stream({ messages: [new HumanMessage(prompt)] });
    for await (const chunk of stream) {
      if ("agent" in chunk) process.stdout.write(chunk.agent.messages[0].content);
      else if ("tools" in chunk) console.log("\n[tool]", chunk.tools.messages[0].content);
    }
    console.log("\n---\n");
  }
}
 
main().catch(err => console.error(err));

npx ts-node --env-file=.env index.ts

Smart-account address: 0xAAc5…eF32
Ask me to do something on-chain (type ‘exit’ to quit)…

Prompt: transfer 0.001 eth to 0x000000000000000000000000000000000000dEaD
✅  Sent a gas-sponsored transaction – hash 0x9eab…1d3a
---

Prompt: what’s my eth balance?
Your smart-account holds ~0.42 ETH on Base Sepolia.
---