HCS Agent Protocol

mkdir hello-hedera-agent-kit
cd hello-hedera-agent-kit
npm init -y

Add "type": "module" to package.json.

npm install @hiero-ledger/sdk @hashgraph/hedera-agent-kit @hashgraph/hedera-agent-kit-langchain langchain @langchain/openai dotenv

Create a .env file with your Hedera credentials and AI provider API key.

// index.ts
import { Client, PrivateKey } from '@hiero-ledger/sdk';
import { AgentMode } from '@hashgraph/hedera-agent-kit';
import { allCorePlugins } from '@hashgraph/hedera-agent-kit/plugins';
import { HederaLangchainToolkit } from '@hashgraph/hedera-agent-kit-langchain';
import { ChatOpenAI } from '@langchain/openai';
import { createAgent } from 'langchain';
import * as dotenv from 'dotenv';

dotenv.config();

async function main() {
  const client = Client.forTestnet().setOperator(
    process.env.ACCOUNT_ID!,
    PrivateKey.fromStringECDSA(process.env.PRIVATE_KEY!)
  );

  const toolkit = new HederaLangchainToolkit({
    client,
    configuration: {
      plugins: allCorePlugins,
      context: { mode: AgentMode.AUTONOMOUS },
    },
  });

  const agent = createAgent({
    model: new ChatOpenAI({ model: 'gpt-4o-mini' }),
    tools: toolkit.getTools(),
    systemPrompt: 'You are a helpful assistant with access to Hedera blockchain tools',
  });

  const response = await agent.invoke({
    messages: [{ role: 'user', content: 'Send 1 HBAR to 0.0.1234' }],
  });
  console.log(response);
}

main().catch(console.error);