Skip to content
0xGasless Developer Documentation

Getting Started

In this guide we’ll build an agent that can find a tool, run it, and pay for it — from a custodied wallet, gaslessly, under a spending policy you control.

Prerequisites

Section titled “Prerequisites”
  • Node.js 18+
  • An LLM API key (OpenAI in the example — any LangChain-supported model works)
  • A 0xGasless API key from your Dashboard project (Project → API Key)

1. Install

Section titled “1. Install”
Terminal window
mkdir my-agent && cd my-agent
npm init -y
npm install @0xgasless/agentkit @langchain/openai @langchain/langgraph @langchain/core dotenv

Create .env:

OPENAI_API_KEY="sk-..."
OXGAS_API_KEY="0xgas_live_sk_..."

2. Configure — platform mode

Section titled “2. Configure — platform mode”

The API key authenticates every action; the wallet lives in 0xGasless KMS. No private key ever touches your process.

import { Agentkit, AgentkitToolkit } from "@0xgasless/agentkit";
import "dotenv/config";


const agentkit = await Agentkit.configureWithPlatform({
  apiKey: process.env.OXGAS_API_KEY!,
  agentId: "my-first-agent",     // created on first use, or via the dashboard
  chain: "avalanche-fuji",       // Avalanche is the primary network
});

3. Hand the tools to your agent

Section titled “3. Hand the tools to your agent”
import { ChatOpenAI } from "@langchain/openai";
import { createReactAgent } from "@langchain/langgraph/prebuilt";


const tools = new AgentkitToolkit(agentkit).getTools();
const app = createReactAgent({ llm: new ChatOpenAI({ model: "gpt-4o" }), tools });

4. Let it work

Section titled “4. Let it work”
const result = await app.invoke({
  messages: [{ role: "user", content:
    "Find a tool that can read a web page, then read https://example.com and summarize it." }],
});
console.log(result.messages.at(-1)?.content);

Behind that one prompt: the agent calls search_tools (free), picks the web reader, calls browse_web → which pays ~$0.05 in USDC from its custodied wallet via x402, settled on Avalanche by the 0xGasless facilitator → and gets the page back. All under the spending policy set on your project.

Funding the agent

Section titled “Funding the agent”

The agent spends stablecoin only — it needs zero AVAX. Send a little USDC (Fuji test USDC works on the free tier) to the agent’s address — ask the agent itself (“what’s your wallet address?”, it calls get_agent_wallet) or copy it from Dashboard → Onchain Agents.

Self-custody mode

Section titled “Self-custody mode”

If you hold the key yourself and want the classic gasless DeFi actions (transfers, swaps, bridges through an ERC-4337 smart account):

const agentkit = await Agentkit.configureWithWallet({
  apiKey: process.env.OXGAS_API_KEY!,
  privateKey: process.env.PRIVATE_KEY as `0x${string}`,
  chainID: 43113,
});

Same toolkit — actions that require the platform (payments, tools, identity) will say so at runtime.

Next steps

Section titled “Next steps”