@402md/agent-tools

Ready-made tools for AI agents to discover and pay for 402.md skills. Framework-agnostic core with a LangChain adapter.

Note: LangChain is currently the only supported framework adapter. Support for Vercel AI SDK, CrewAI, and others is planned. The framework-agnostic core (ToolDef) can be used to build custom adapters for any framework.

Install

npm install @402md/agent-tools @402md/cli

For LangChain:

npm install @402md/agent-tools @402md/cli @langchain/core

Quick Start

Initialize your project with one of the two payment modes:

Wallet-pay — uses a managed wallet created on the 402.md dashboard. The backend handles gas and signing on your behalf (recommended for getting started):

npx @402md/cli init \
  --mode wallet-pay \
  --api-key sk_your_api_key \
  --wallet 0xYOUR_WALLET_ADDRESS \
  --network base-sepolia

x402 — self-custody mode. You provide your own private key and the agent signs USDC transfers directly on-chain:

npx @402md/cli init \
  --mode x402 \
  --key 0xYOUR_PRIVATE_KEY \
  --network base

To point at a custom backend (e.g. local development):

npx @402md/cli init \
  --mode wallet-pay \
  --api-key sk_your_api_key \
  --wallet 0xYOUR_WALLET_ADDRESS \
  --network base-sepolia \
  --api-url http://localhost:3001

Then install a skill:

npx @402md/cli add <skill_name>

import { ChatAnthropic } from '@langchain/anthropic'
import { createAgent } from 'langchain'
import { HumanMessage } from '@langchain/core/messages'
import { createAll402Tools } from '@402md/agent-tools/langchain'
import type { StructuredToolInterface } from '@langchain/core/tools'

const paymentTools = createAll402Tools() as StructuredToolInterface[]

const agent = createAgent({
  model: new ChatAnthropic({ model: 'claude-sonnet-4-6' }),
  tools: paymentTools,
  systemPrompt: 'You are an AI agent with a USDC wallet on Base.',
})

const result = await agent.invoke({
  messages: [new HumanMessage('Check my balance and call ditto at /test')],
})

API

LangChain (@402md/agent-tools/langchain)

import {
  create402Tools,                  // 2 core tools: balance, call
  create402SearchTool,             // 1 tool: search (opt-in)
  createToolsFromInstalledSkills,  // 1 tool per installed skill
  createAll402Tools,               // all combined (core + search + skills)
} from '@402md/agent-tools/langchain'

All functions return DynamicStructuredTool[] and accept an optional { projectDir?: string }.

Framework-Agnostic (@402md/agent-tools)

import { createCoreTools, createSearchTool, createSkillTools } from '@402md/agent-tools'

// Core tools (balance + call)
const tools = [...createCoreTools(), ...createSkillTools()]

// Add search if needed
const allTools = [...createSearchTool(), ...tools]

// Each tool: { name, description, schema, execute }
const result = await tools[0].execute({ query: 'sentiment' })

Tools

| Tool | Source | Description | |------|--------|-------------| | check_balance | create402Tools | Check USDC wallet balance | | call_skill | create402Tools | Call any skill with automatic payment | | search_skills | create402SearchTool | Search the 402.md marketplace (opt-in) | | <skill-name> | createToolsFromInstalledSkills | One tool per installed skill (auto-generated) |

Error Handling

Tools never throw. If payment isn't configured, they return:

{ "error": "No payment configured. Run:\n  npx @402md/cli init ..." }

Examples

See the examples repo for complete working demos, including an interactive LangChain agent with autonomous payments.

License

MIT