aiworker x402 tools for LangChain.js

One import that turns the public aiworker OpenAPI catalogue into LangChain tools. Each tool pays for its own call over x402 from the buyer's wallet.

Install

pnpm add @langchain/core @x402/core @x402/evm @x402/fetch viem zod

Then copy src/ (catalog.ts, schema.ts, payer.ts, tools.ts, index.ts) into your project.

Wallet

You need a Base wallet funded with USDC. The key lives only in an env var, never in code:

export AIWORKER_BUYER_KEY=0x...

Use

import { aiworkerTools } from "./src/index.js";
const tools = await aiworkerTools({
  privateKey: process.env.AIWORKER_BUYER_KEY as `0x${string}`,
  maxPriceUsd: 0.05, // skip anything pricier; omit for no cap
});

Routes and prices

| Route | Price | |---|---| | GET /v1/token/info | $0.005 | | POST /v1/polymarket/backtest | $0.25 | | POST /v1/scrape/markdown | $0.02 |

The live catalogue has seventeen paid routes; the table above is the trimmed fixture in test/fixtures/openapi.json.

Example

AIWORKER_BUYER_KEY=0x... pnpm example

Lists the tools under the cap, then calls token/info once for Base USDC and prints the answer plus the settlement hash.

What it does not do

• No Solana: EVM (Base) only.
• No MCP wrapper.
• No retries of a failed settlement: a non-2xx answer is returned as an {"error", "body"} string for the agent to handle.
• No price negotiation: catalogue prices are fixed per route.